How to Check Heated Seats

The heated seats in newer automobiles produce heat via a coiled wire. As power travels through the coil, its winding design resists the electricity and therefore generates friction and heat. Heated seats can malfunction for a number of reasons. Whether the defect lies in the fuse, the electrical connections or the heating coil, having a thorough troubleshooting protocol will enable you to determine the problem with your heated seats quickly every time.

Instructions

Locate the fuse box in your vehicle, and check the fuse for the heated seats to see whether or not it is broken. If it is broken, remove it and install a new fuse.

Start your vehicle, and then flip the relay switch for the heated seats on. Most vehicles feature a "heated seat" light on the dash that comes on when you turn the relay switch on. If this light fails to come on, there is a problem with the relay switch. Unscrew the dash using a Phillips screwdriver, and then touch one of the voltmeter probes to any of the wires connected to the relay switch. Touch the other probe to the relay switch grounding wire and read the meter. Any wires that fail to register any electrical current at all will need to be replaced.

Turn the relay switch on, and then test the electrical circuit that feeds the heated seat. Place one probe on the power lead that connects to the heated seat connection and the other probe on any metal part of the seat. If the meter does not register any current, the power circuit will need to be replaced.

Pull off the electrical connection for the heated seat by hand. Test each of the three pins in the connector by placing on voltmeter probe on a pin and the other probe on any metal part of the seat. If any pin fails to register current, the connector any need to be replaced. If the pins are covered with dirt and debris, clean them off with a rag. This may be enough to fix the problem.

Place one probe on the power lead that is fed by the heated seat connection and the other probe on any metal part of the seat. If the meter does not register any current, the circuit that is fed by the heated seat connection will need to be replaced.

Unbolt the seat from the vehicle using a ratchet and socket, then unplug the two electrical connections that are attached to the seat. Pull the seat out of the vehicle and remove the circular "hog rings," which connect the seat cover to the seat, with pliers. Pull the seat cover off and look for burn marks. If every other test has been positive, the heating coil needs to be replaced.

How Oxygen Sensors Work to Control Fuel Trim And Emissions

The O2 sensor measures the oxygen content of the exhaust. The O2 sensor’s sensing ability comes about by producing a small voltage proportionate to the exhaust oxygen content. In other words, if the oxygen content is low it produces a high voltage (0.90 Volts - Rich mixture) and if the oxygen content is high it produces a low voltage (0.10 Volts - Lean mixture). Although theoretically the O2 sensor should cycle between 0.00 volts and 1.00 volts, in reality it cycles between 0.10 volts and 0.90 volts.

A GM O2 sensor signal stuck at 450 mV is an indication of an open O2 sensor circuit (signal wire) or faulty O2 signal ground. The 450 mV value (GM) is called a bias voltage and it is not the same for all manufacturers. Some manufacturers employ a dedicated O2 sensor ground. Such a ground lead is attached to the engine block or chassis and feeds an ECM O2 ground pin only. The O2 circuit is then grounded through the inside of the ECM electronic board by this ground wire. A loss of this ground would also put the O2 sensor signal at around 450 mV, which also makes it look like an open circuit. The same holds true for Chrysler, but these use a different O2 bias voltage, which is usually 2.00 to 4.00 volts

1) A few key issues are very important in the analysis of O2 sensor signals. 2) An O2 sensor will cycle between 0.10 to 0.90 or almost 1 volt. 3) An O2 sensor has to reach the 0.8x Volts amplitude mark while at full operation. 4) An O2 sensor also has to reach the 0.1x Volts amplitude mark while at full operation. 5) Full operation means the engine is fully warmed up, O2 sensor above the 600 deg. F. operating temperature, and no fuel or mechanical problems present. 6) The O2 sensor must cycle at least once per second, which would show 3 cross counts on the scan tool PID. 7) Silicone is the leading cause of O2 contamination. 8) It is easier for an O2 sensor to go from rich to lean than vise-versa. 9) O2 sensors tend to fail on rich bias. In other words, they tend to shift their cycling to the upper side or rich side of the voltage scale. 10) Contrary to what many people think, an O2 sensor WILL NOT cycle by itself. The O2 sensor cycle is a direct result of the ECM response to the changes in the mixture. 11) Any time the O2 cycles and crosses the 0.450 volts mark, the system is in CLOSE-LOOP. 12) Even though an O2 sensor is cycling and crossing 0.450 volts (ECM in close loop) it DOES NOT mean that it is working properly. 13) O2 sensor operation is extremely important not only to keep HC & CO emissions low but also to the NOx as well. 14) Proper O2 sensor cycling will determine the catalytic converter’s efficiency. The catalytic converter needs the O2 sensor cycling at its proper amplitude and frequency for it to function at its maximum efficiency. 15) An O2 sensor with a high voltage reading does not necessarily mean that the mixture is rich or high in fuel content. An EGR valve problem will send the O2 signal high as well.

A big misconception among technicians trying to understand O2 sensors is that they cycle by themselves. The O2 sensor just reads oxygen content in the exhaust, THAT’S IT. Excess oxygen in the form of regular ambient air will send the O2 sensor voltage signal low (under 0.450 volts) and lack of it will send the voltage signal high (over 0.450 volts). A stuck open EGR valve will create a lack of oxygen in the exhaust, since the re-circulating exhaust has all its oxygen already burnt. The ECM sometimes uses the O2 sensor to check for proper EGR operation and sets a code if necessary. So, be aware of the fact that a vehicle might be running lean because the ECM sees a rich O2 signal due to a defective (stuck open) EGR valve. Since the ECM sees a rich signal, it will try to correct with a lean command and try to lower the O2 sensor’s high voltage signal.

CONDITION THAT AFFECT OPERATION

NOTE: WHEN PERFORMING O2 SENSOR CHECKS, IT IS IMPORTANT TO TAKE MEASUREMENTS AT IDLE AND 2000 RPM. BE AWARE THAT O2 SENSOR PRE-CONDITIONING IS IMPORTANT, EVEN ON THE NEWER STYLED HEATED O2 SENSORS. PRE-CONDITION THE O2 SENSOR BY RAISING THE ENGINE SPEED TO 2000 RPM FOR ABOUT 15 SECONDS OR SO. THE O2 SENSOR HAS TO BE ABOVE 600 º F. TO BE ABLE TO OPERATE PROPERLY. LONG PERIODS OF IDLE TIME CAN RENDER A NON-HEATED OR OLDER O2 SENSOR TOO COLD FOR IT TO FUNCTION AT ALL. AT THE SAME TIME, DO NOT TRY TO FORCE A HEATED O2 SENSOR INTO OPERATION. AN O2 SENSOR WITH A FAULTY HEATER WILL GO INTO CLOSED-LOOP AFTER A GOOD WARM-UP SESSION.

After an engine has ran through its warm up period (O2 sensor has no effect on engine operation while the engine is cold), the ECM then looks for the O2 value. The 0.450 volts mark is considered almost universally as the midway point or crossover point for O2 sensor operation. If the signal is on the rich side (above 0.45 volts), then the ECM will answer with a lean command (reducing injector pulsation), or if the signal is on the lean side (below 0.45 volts) then the ECM will answer with a rich command (increasing injector pulsation). The amount of injector pulse correction is proportional to the voltage seen by the ECM at the O2 sensor signal wire. The higher the voltage the more the ECM reduces on-time to the injector. The lower the voltage the more the ECM increases the injector on-time. The ECM is constantly doing exactly just that, slightly increasing and decreasing injector pulsation. The constant adjustment is what gives the O2 sensor signal the switching appearance (sine wave) on the scope screen.

NOTE: The ECM’s fuel pulse corrections performed constantly to the injector signal is called SHORT TERM FUEL TRIM (GM called it INTEGRATOR) and LONG TERM FUEL TRIM (GM called it BLOCK LEARN) on the scanner. FUEL TRIMS is the system’s deviation of the BASE-INJECTION pulse. Analyzing LTFT and STFT is a great way to know a particular vehicle’s fuel consumption trend or how well that vehicle has been performing with regards to fuel control. STFT and LTFT is the first thing to look for when assessing fuel control problems.

The fact that the O2 sensor signal is switching rich-lean-rich-lean also reveals that the ECM is controlling the injector pulsation and therefore that the system is in close loop mode. An ECM in full control (O2 sensor cycling) is said to be in close loop because of the close-circuit action of O2 sensor-to ECM-to injector pulse control then to O2 sensor and back to the ECM. The ECM must be in control at all times except during warm up, WOT, power enrichment, and deceleration mode.

The O2 sensor not only has to cycle, it also has to cycle fast enough (proper frequency) and wide enough (proper amplitude). At least one cycle per second (1 Hz) must be seen at the signal wire in order for the O2 to be considered good (not lazy). A one cycle per second will make the scope trace go across the 0.450 volts mark approximately 3 times, which the ECM recognizes as 3 cross counts. A slow O2 sensor will have a damaging effect on the catalytic converter and release excessive amounts of emissions to the atmosphere.

A cycle is the complete rich and lean crests of the O2 sensor signal, while crossing the 0.45 voltage point. Proper amplitude refers to the O2 sensor’s ability to reach full rich (0.90 volts) and full lean (0.10 volts) when cycling. The higher the voltage seen at the O2 signal line the more the ECM reduces pulsation to the injectors. The lower the voltage seen at the O2 signal line the more the ECM increases injector pulsation. This is the reason why an O2 sensor that is not reading the mixture properly, at full amplitude and frequency, will actually misguide the ECM into a wrong fuel control pattern. Once the O2 sensor has reached its correct temperature of 600 º F, look for an O2 signal cycle with the correct amplitude and frequency and it will surely indicate a perfectly operating O2 sensor.

COMPONENT TESTING

NOTE: On early OBD II systems, the post catalytic converter O2 sensor has no effect on fuel control. The post catalytic O2 sensor was originally responsible for only monitoring catalytic converter efficiency. On most systems, the post converter O2 sensor signal should never mimic or follow the pre-cat O2 signal. That would indicate a defective or low oxygen storage capability at the converter. On early OBD II systems, the post-cat O2 sensor should show little or no voltage fluctuations on a scope waveform, since all the mixture fluctuations are being absorbed by the catalytic converter.

Stating around model year 1999, a new type of converter came on the market, called “Low Oxygen Storage Converter” or LOC. With an LOC, the pre and post O2 sensors cycle at the same rate. These converters are tested by measuring the lag-time between the two signals. A further development of this system is that the post converter signal is also used for A/F correction, but to a less extent.

These simple steps should be followed whenever testing O2 sensors.

           

Scan the vehicle for any O2 sensor codes and analyze the data stream PID. O2 sensor voltage should cycle normally with proper amplitude and frequency. An O2 sensor stuck at a fixed bias voltage is an indication of an open O2 circuit or lack of O2 sensor (dedicated) ground. If possible use a graphing multi-meter to analyze the O2 sensor data to determine any possible problems.

           

While reading the scan values, goose the throttle and observe for O2 sensor minimum and maximum values (0.1x volts to 0.9x volts). Although this is not a conclusive evidence of correct O2 sensor operation, it serves as a preliminary indication of proper operation.

           

Some automotive manufacturers employ a dedicated O2 sensor ground wire that is grounded somewhere at the engine block or chassis. A loss or rupture of this ground wire will render the O2 sensor useless. This ground wire feeds only the ECM’s O2 sensor circuit. The main engine ground does not feed this type of O2 sensor circuit.

           

Verify the O2 sensor wire integrity. Most O2 sensors are biased and an open signal wire will give a reading of whatever the bias voltage is. Later model Jeep/Chrysler O2 circuits tend to be biased at around 2 or 4 volts; therefore, a constant reading of around 2 or 4 volts on a Chrysler is also an indication of an open circuit. In many of these cases, the ECM will put an “O2 sensor High Voltage” code.

           

Finally, verify for correct O2 sensor operation with a scope or graphing multi-meter. Check for proper amplitude and frequency. Remember that the scanner O2 sensor readings are only interpreted values and may not show the real voltage reading. This is the reason for doing this final manual test.

  

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Find That Short

 Nothing can be more frustrating or confusing than trying to find a short in your car's electrical system.  Especially when it's not enough to blow a fuse but still drains your battery!  Obviously, if you find a blown fuse, replace it; turn the key on, and the fuse blows immediately you've found the circuit within your car's electrical system that the short is in.  However, if the draw does not create enough current to blow a fuse, than we have to find out which circuit it's in to fix it.   Before I get started, my intention in this Tech Tip is not to teach Electrical Systems and Electronics.  Instead, I just hope that this article will give anybody a systematic approach to finding a short.  So let’s get started...

First, let’s make sure that you have a short!  Electrical systems have a specific route for electricity to travel along and any change from this route causes problems.  If electricity can find an easier route it will always take it.  So let’s find out if the electricity in your car is finding a ground sooner than it's suppose to...  What we're going to do is take a test light and attach the clip end to the negative battery cable and put the tip on the negative battery post.   Then we're going to remove the

Negative battery cable making sure we don't touch the test light.  Now we haven't broken the electrical connection here.  All we're doing is letting the current, if any, flow out of the negative battery post, through our test light to see if it illuminates, and continue on along the negative battery cable to the short.  Word of caution, If you're attempting this on a computer controlled car it is very important not to break the connection of the test light to the negative battery post.

By not breaking the connection, the computer will maintain it’s learned driving strategy in the Keep Alive Memory (KAM).  It will also ensure your computer will not have to go to factory baseline and relearn controlling your car's engine for maximum fuel economy and performance.  While we're on the subjects of computer control, module equipped cars have a small parasitic drain caused by the modules' KAM.  This is normal and module or modules can draw 10-21 milliamps (mA) with the key off. 

If you have a parasitic draw that is in the milliamp range and is beyond normal specs, you will have to use an Amp Probe for a Digital Volt Ohm Meter (DVOM) to diagnose this and the method below may not work due to the very low current draw.  

by the way, a DVOM can be used in place of a test light.  Just ensure your leads are in the proper connections to measure Amps.   Using this tool will not only tell you if you have a current draw when you're not supposed to, but will also tell you how many Amps are being drawn.

Okay, you've confirmed you have a short, now how do you find it?  The first and easiest test is disconnecting the alternator and see if the test light goes out or the DVOM display changes.  Often old or worn out alternators ground themselves internally causing a short.  If it does you've found your short and repair or replace the alternator or appropriate components.  If the test light remains lit or the amperage on the DVOM does not change, you have to try and start isolating which circuit within your car's wiring has the short.  This can be done by pulling fuses one at a time.   A fuse is nothing more than system protection.  All the current that flows through a circuit must go through the fuse.  By pulling a fuse we've created an open and current can no longer flow.  Continue doing this until the light goes out or the DVOM display changes showing no current draw.  Once you've found the circuit that has the short you must find where in that circuit the short is located.  It's always best to take the least intrusive method to diagnose.  Besides, who wants to tear out the dash or remove the interior just to trace a wire? 

When electricity flows through a wire it creates  magnetism.  We're going to use this magnetism to find our short!  Many tool vendors and auto parts stores sell short detectors.  The one in my tool box is from MAC.  It's convenient for me because it also has an audible alarm which I can hear in a noisy shop environment.  I'm pretty sure NAPA sells one also.  The tool consists of a 10 Amp circuit breaker with buzzer, wire leads, clips, and a compass.  But for our purposes we're going to make our own which I believe is better than the ones you can buy. To make our short detector, we'll need the following items: 1 x 20 Amp circuit breaker 2 x alligator clips 2 x spade connectors 2 x 2 foot pieces of 18ga wire 4 x 1 foot  pieces of 18ga wire 1 x magnetic compass of any type *modify length of wires to meet your needs*

Connect the pieces together as shown. This should allow you to hook your tool up in place of a fuse no matter what type of fuses your car uses.  The reason I recommend a 20 Amp circuit breaker instead of a 10 Amp one is it allows current to flow longer and thus building more magnetism.   This is important especially if the wire that the short is in is buried under items like the carpet, rocker cover, door panel, pillars, etc.  The more magnetism we can build the easier it will be to pick it up with our compass.

At this point it helps to know how the wiring loom or wires run for the circuit that has the short.  A schematic is very helpful here especially if it has component locations.  If you cannot find one or your vehicle is older you will have to trace the wire(s) from the fuse on...but this is not that hard and you'll see why.  The reason we want to know which way the wire is going from the fuse box is because we're going to use the magnetism that is built buy the electricity along that wire to locate the short.  Place your tool into your fuse box or where you pulled the burnt fuse from instead of the fuse and turn the key on to the RUN position.  Now what's going to happen is electricity is going to flow to the short.  Because we have a circuit breaker in there instead of a fuse we're allowing magnetism to build along the wire.  As the current flows through the circuit breaker it starts to heat up (careful the tool may get very hot).  The bi-metal strip inside the circuit breaker will eventually bend away from the contact breaking the circuit and creating and open before any damage can be done.  This is always associated with an audible "CLICK" from the circuit breaker.  With an open, no current can flow through the circuit breaker and the shorted circuit.  With no current flowing, the bi-metal strips cools very quickly and reforms itself back to its original shape and touches the contact allowing current to flow and once again creating magnetism.

We're going to use this magnetism and our compass to locate the short. A wire (conductor) will build magnetism.   A short will not.  So we put our compass along the wire or wire loom and the current flowing through the wire is building magnetism.  This magnetism will draw the north seeking arrow on the compass towards it (one way or another).  We leave our compass in place until we hear the "CLICK" from the circuit breaker.  When the circuit breaker opens the magnetism will be lost and the north seeking arrow of the compass will deflect back towards the magnetic pole of the earth momentarily.  This deflection is important!   Because once we get to our short there will be very little or no deflection at all.   So after each click and deflection we move the compass about 6-12 inches along the wire, wait, and watch for the needle to deflect as the circuit breaker opens and closes.  We continue doing this until we come to a portion of the wire where the needle is not being drawn towards the wire (weak or no magnetism) and there's no deflection of the compass needle when the circuit breaker opens.   Congratulations! You've found the area where the short is located.  However, you still have not found the short, but at least you know where to dig in.  Expose that portion of the wire and locate the short in the wire.  Here's a hint - if there's a bunch of wires there, shorts create heat.  So look for the hot wire, hot metal, or hot component.  Then look for any wire or component that may be broken, cracked, smashed, exposed, or punctured.

Now that you've found the short, repair it by splicing in a new piece of wire, fixing, or replacing the shorted component.  You can cut & solder, use a butt connector, or electrical tape if you have nothing else.  At one time automobile manufactures only recommend solder, however, the quality of butt connectors are so good today that many allow this type of repair.

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Why does my Battery Drain - Parasitic Draw Testing

 Battery Drain 

Parasitic Draw Testing

What is parasitic draw? All vehicles draw some power from the batteries when the car is shut off. Certain accessories such as clocks, radios remote door openers and alarms always need power. The normal power used is called parasitic draw. It is always a very low draw so it doesn't run the battery down. If you install accessories or plug things like invertors into the accessory socket and operate them too long without the engine running you can drain your batteries to the point where the engine won't start. If there is an electrical short in the vehicle or a malfunctioning accessory it could be drawing much more than its normal load causing a drain on the batteries. If you leave your door open and the inside lights stay on all night you could drain the battery down till the car won't start. 

The first thing to do is a test for a major short. Remove the positive and negative cables from the batteries. Put an Ohm-meter across the positive and negative cable. If your reading is close to 0 Ohms then you have a direct short. You need to trace the short before you can perform the following tests.

In order to check for parasitic draw, you need to be careful so you don't ruin your meter.
 If you don't already have one, get a digital meter capable of reading up to 10 amps DC. Sears sells them for less than $50.
Your battery must have a reasonable charge for this test - it won't work if your battery is dead. Quick proof - if your dome light operates normally, you're fine.

·        Check to make sure ALL loads are turned off. Unplug anything you may have plugged into the cigarette lighter. Remove your keys from the ignition. Close all doors so the dome lights are off.

·        Disconnect the thick positive (Red) cable that goes down to the starter.

·        To start make sure your meter is set to the 10 amp DC range. Some meters have a special connector for the red probe when you are reading current. The meter pictured on the left has one jack for high amps and one for low amps. If yours does make sure the meter end of the probe is in the right connector. You can either do this next step by just holding the meter probes to their respective contact points (you won't get a shock from 12 volts) or you can use probes with alligator clips to snap them in place so your hands are free to do something else.

·        Connect the positive probe to the battery - either battery is fine, electrically speaking, since they are connected together by the negative (Black) wires. Polarity on digital meters doesn't matter because they are auto-sensing.

·        Connect the negative probe to the red cable that is still connected to the vehicle. Make sure this cable and your probe do not touch ground.

·        If there is a severe current draw (more than 10 amps) it will either pop a fuse in your meter or destroy it outright. That's why you need to test for a short; otherwise, your meter should now be reading the current drain on your battery.

·        If your vehicle has an alarm system or remote locks, the current draw may be around 2-3 amps for a few minutes after you last close the door. This is normal. If you're not sure, wait at least 20 minutes after you last open or close a door before you take a reading.

·        If everything is normal, you will read less than 35 milliamps, or .035 amps. If the current drain is higher than that, you need to find out what is draining your batteries: You can start by pulling fuses until the load goes away. If that doesn't reduce the draw, you need to look for a wire that is corroded or frayed.

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Evaporative Emission System

When we think of automotive emissions, we often think of the dirty stuff coming out of our exhaust pipes. The internal combustion process creates noxious chemicals (like CO2 and nitrogen oxides) that are released into the air as we drive. But tailpipe emissions are controlled using a variety of systems like catalytic converters and exhaust gas recirculation systems, and they're regulated by state and federal legislation.

However, did you know that there's another type of emission that comes from our cars? They're called evaporative emissions. The gasoline in your fuel tank and in you fuel lines slowly evaporates over time, releasing volatile organic compounds into the air. The Environmental Protection Agency says there are enough of these emissions to contribute to air pollution and pose a health risk to humans.

Because of their harmful nature, the government also regulates these evaporative emissions in new vehicles. This means that carmakers are required to install evaporative emissions control systems onto every new car and truck they build. These systems have been in place since the early 1970s. But as technology advances, car companies find newer and more innovative ways to mitigate pollution. I’ll tell you how evaporative emissions control systems work, and ways you can prevent your vehicle's fuel from evaporating under certain conditions.

Controlling Emissions

The fuel we put in our cars contains more than 150 chemicals, including benzene, toluene and sometimes even lead. These ingredients can cause dizziness, breathing problems and headaches when they're inhaled. Inhaling large amounts of gasoline fumes can even cause death. On top of all that, evaporated gasoline is one of the leading causes of smog and air pollution.

For these reasons, carmakers are required to install systems on their vehicles that help mitigate gasoline evaporations. Environmental regulation in the United States began in earnest in the early 1970s, and as a result, cars have had evaporative emission control (EVAP) systems ever since. These systems are designed to store and dispose of fuel vapors before they can escape into the atmosphere.

A typical system consists of a small canister full of charcoal, valves, hoses and vents in the fuel lines and a sealed fuel tank cap. When fuel evaporates inside the gas tank, the excess vapors are transferred to the charcoal canister. They're stored there until they can safely be transferred back to the engine to be burned with the normal air-fuel mixture.

When that's ready to happen, a valve creates a vacuum that draws the vapors into the engine. Fresh air is also drawn in through the vents and valves to mix with the vapors for better combustion. These systems can be controlled mechanically, or like on most on newer cars, through the engine's computer. The computer tells the valves when to purge the canister of vapors. This typically happens when the car is in motion, rather than at idle. As you may expect, things can go wrong with the EVAP system, too. If the canister fails to purge or does so under the wrong conditions, it can hamper the performance and emissions of your vehicle.

Keeping Gas Evaporation Down

It's no secret that gasoline is volatile. And it evaporates quickly, too. In fact, your car's fuel can turn from a liquid into a gas at a very fast rate, especially when it's hot outside. This is bad for the environment, with 20 percent of all hydrocarbon emissions from cars coming from fuel evaporation. It's bad for your wallet, too. Unless you're an executive at an oil company, you probably aren't a fan of the way gas prices have been on a steady rise over the past few years. It's bad enough that your car burns gasoline, why do you also have to lose more to evaporation? The good news is that there are things you can do to your gasoline to slow the process down from evaporating. First and foremost, make sure your fuel cap is secured tightly. Fuel can escape right out of your tank if it's not airtight. Whenever possible, park in the shade during the summer months. Even though modern cars have advanced EVAP systems to prevent too much evaporation from occurring, gas does still evaporate from the tank, especially when the car is parked in the sun. This is even worse when it's extremely hot outside. Parking in the shade helps keep the entire vehicle cooler and reduces fuel evaporation.

Buy your gas in the early morning or later at night. It's warmer in the afternoon and early evening, which means evaporation is more prevalent. That's why you're sometimes hit with that nasty gasoline smell at filling stations during the heat of the day.

P0440 OBD-II Trouble Code

This indicates that a part of the EVAP control system is no longer functioning correctly. The EVAP system consists of many parts, including (but not limited to) the gas cap, fuel lines, carbon canister, purge valve, and other hoses. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. When the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine. A code P0440 could mean one or more of the following has happened: The gas cap is not installed or working properly the purge solenoid has failed the canister is plugged and not working properly

Possible Solutions with a P0440 OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try:

• Remove and reinstall the gas cap,
• Clear the code, and drive for a day and see if the codes come back.
• Inspect the EVAP system for cuts/holes in tubes/hoses Inspect for damaged or disconnected hoses around the Evap purge solenoid
• Check and/or replace the sensor
• Check and/or replace the purge valve Have a professional use a smoke machine to detect leaks

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Diagnostic Fees

So you bring your vehicle to an auto repair shop to determine the cause of a particular problem that your car is experiencing. The mechanic takes a look at your car, hooks your vehicle to a computer for a scan, and then tells you the cause of the problem—giving you repair options and their corresponding amount. You think you’ll be able to fix the problem yourself, so you decline. Then the mechanic gives you the bill: a whopping $100 for the diagnosis! Should you or should you not pay? A mechanics service is not free so expect to be billed for all diagnosis. A mechanic cannot automatically know the repair to your vehicle unless it is diagnosed.

All auto repair shops today charge a diagnostic fee on top of the fee for the actual repair. And in reality, this is valid. You need to pay for the service of the mechanic who did the diagnosis. Mechanics compare this to paying for a doctor when you go in for a consultation. In some instances when you let the shop do the repair, it can just include the diagnostic fee on the entire fee for the repair done. In cases when the diagnostic done was just a simple one, the shop owner can also decide not to charge for the diagnosis—but that’s up to the shop owner.

In the end,you will pay a diagnosis fee if only to be sure that the person handling your vehicle is someone who is an expert at what he does and someone who is capable of determining the real problem of your ride. If you want to avoid an exorbitant diagnostic amount, you can do your shopping in advance to find the usual diagnostic rate. You can also ask the shop in advance before the mechanic does anything with your vehicle. This way, you won’t have to deal with surprises when you finally get the bill and you see a three-figure amount for a simple diagnosis. Diagnosis is usually charged by the flat rate hour and you should be asked if you want to continue diagnosis or not. If after an hour or two the mechanic has not gotten to the root of the problem you must make a decision whether you want to continue, because it will get more expensive and the repair has not begun yet.

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A Few Ways to Extend the Life of Your Car

Simple things you can do to extend the life of your car are to first of all check your oil every two weeks and follow the recommendation in your owner’s manual. If you do a lot of city driving you will want to adjust the manufacturers recommendations and choose these steps a lot sooner.

 Oil changes are an extremely important and simple way to care for your car. Oil keeps the parts of your car lubricated, which in turn reduces friction, allowing the parts to last longer. Over time, however, oil breaks down due to the high heat, becoming less effective; hence the need for oil changes.

 Don’t Ignore Problems. No matter how long you wish the check engine light would go away, it’s not going to. But the longer you drive with a problem, the more serious it will become and could end up costing you a lot more money. So take your car to a qualified mechanic sooner rather than later and you’ll spend less in the long run.

 Don’t Neglect the Air Filter. Most don’t give the air filter much thought but it’s crucial for preventing debris from getting in the engine and causing unnecessary wear. A dirty filter does this less effectively and can also cause the fuel injector to produce an incorrect air to fuel ratio needed for the car to run. Make sure to change your air filter regularly consult the manual for how often.

 Check your fan belts and hoses for wear and tear and replace them before they break. A noisy belt is a sign of it wearing out. Check the tires for abnormal wear. Rotate the tires every 7,500 miles to preserve them. Have wheel alignment done every time the tires are replaced or when there is abnormal wear found. Check battery terminals for white deposits. Use a wire brush to remove deposits. Lubricate door hinges and locks with a penetrating grease or graphite lubricant spray once a year.

 Keep the car clean inside and out. Wash and wax the outside. This will keep the paint from fading especially in hot and sunny climates. It also gets rid of road salt and other harmful substances that can cause rust and have a negative impact on your cars performance. I know that gas is expensive these days. And you may think that you are saving money by using regular instead of premium octane fuel. However, regular is going to burn slower and cause deposits and carbon build up a lot faster than premium. You will need to perform tune up and maintenance more often.

 Save hundreds of dollars by doing some simple repairs yourself. You can learn techniques for changing wiper blades, replacing your air filter, changing the oil, or replacing your battery. Before you begin, do a little homework, get the tools you need and remember to safely dispose of any liquids that come out of your car. By doing something simple, such as paying attention to leaks, you can get your car to the service dealer earlier and save money on costly repairs. Knowing the normal color of engine oil and other fluids will make it easier to detect a problem, and will also tip the service manager that you know what you’re doing. Brown fluid is engine oil; bright green or orange fluid is anti-freeze or coolant; clear or light brown fluid is clutch or brake fluid.

 Becoming familiar with how to perform your own maintenance is a great way to make sure that when the service adviser is explaining what is wrong or what is needed on your car you will clearly understand.

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