Top 5 reasons your check engine light might come on

While maintenance is expensive, it's crucial as people hang on to their cars longer. According to R.L. Polk, an automotive data firm, the average vehicle on the road is now 10.6 years old, up from 8.8 years a decade ago.

Here are the five most common reasons your "check engine" light might come on, and what you can expect to pay for the repair, including labor, according to CarMD:

1. Faulty oxygen sensor The sensor measures the amount of unburned oxygen in the exhaust and tells the car's computer how much fuel is in the tank. If a faulty one is not repaired, the car's gas mileage could drop, since the sensor is sending incorrect information to the car. It costs less than $200 to repair.

2. Loose or missing gas cap Technicians will often tighten the gas cap for free, or replace it for a few dollars. If it's not replaced, gas will evaporate from the car and decrease its gas mileage.

3. Broken catalytic converter This one isn't good news, since it can cost up to $2,000 to replace. The catalytic converter uses a catalyst — most often a precious metal such as platinum — to convert harmful gases left over from combustion to less harmful emissions. CarMD says catalytic converters generally won't fail unless a related part, such as a spark plug, malfunctions, so it's wise to keep up with the car's maintenance schedule.

4. Malfunctioning mass air flow sensor This sensor measures the amount of air supplied to the engine, which determines how much fuel should be delivered. When it malfunctions, it can result in a loss of power to the car, surges during acceleration and a decrease in fuel economy. It costs around $375 to fix.

5. Misfiring spark plugs Spark plugs are small but essential, since they make the car go by igniting the compressed fuel in an internal combustion engine. Misfiring spark plugs can affect engine power and fuel economy and can also damage the catalytic converter. You can replace spark plugs yourself for as little as $10 or pay $300 for a technician to do it.

CarMD says the total average repair cost in the U.S. is $305.56, including $202.28 for parts and $103.27 for labor.

The report is based on data from 170,000 vehicle repairs made between 1996 and 2010. The data came from vehicle owners and technicians who downloaded information to CarMDThe most expensive cars to repair? Hybrids. They remain rare enough that their parts are pricier and fewer technicians are trained to fix them.

source: http://www.msnbc.msn.com/id/42902305/ns/business-autos/t/reasons-why-your-check-engine-light-might-be/#.Tzx0hsVOg1I

Fiat check engine list / fault code / trouble code

Get all Fiat specific code here :

http://www.permoveo.ltd.uk/tabid/123/Diagnostics/Fiat/Default.aspx

Dacia check engine list / fault code / trouble code

All Dacia trouble code here.

http://www.permoveo.ltd.uk/tabid/123/Diagnostics/Dacia/Default.aspx

Alfa Romeo check engine list / fault code / trouble code

Get all Alfa Romeo code here

http://www.permoveo.ltd.uk/tabid/123/Diagnostics/Alfa-Romeo/Default.aspx

Daewoo check engine list / fault code / trouble code

The information below may apply to Daewoo Lanos, Matiz, 1.5i and many other models Connector Diagram Note:This vehicle my not give flash codes. You may need the OBD2 / EOBD or UniPlug vehicle specific software. Auto Repair Manual - How to read codes (No Special Tools Needed) 1 If possible run the engine to bring the oxygen sensor up to operating temperature then switch the engine off. 2 Connect the terminals using your own jumper wire. 3 Turn ignition ON, the Check Engine Light (CEL) should be flashing. 4 Read codes as described in the Code Format Description below. 5 Press the continue button to enter the code numbers and get the code description(s). Code Format Diagram Fault Code Description • Each code is made up of two series of flashes. • The first series indicates the 'tens' digit. • The second series indicates the 'ones' digit. • A long pause separates each code. • A shorter pause separates the 'tens' and 'ones'. • Code Format Diagram shows code No. 32. • The first code "flashed out" is always code 12. • If Code 12 repeats at least 4 times in a row there are No Codes in memory. • Codes repeat 3 times each, then the next code repeats 3 times...

Get all Daewoo codes here !

http://www.permoveo.ltd.uk/tabid/123/Diagnostics/Daewoo/Default.aspx

How to reset check engine light

When it comes to the reset check engine lightprocess there are not as many options today as there where for cars built prior to 1996. Before the invention of OBD 2 resetting your check engine light was a simple matter of disconnecting the battery for more then 10 seconds.

OBD II was deployed in 1996 and changed the way codes are set and stored in the on-board computer. If your vehicle is newer or post mid 90's I do not recommend that you disconnect the battery for resetting the service engine soon light. Stick with me I will explain how to reset check engine lights by disconnecting the battery.

Yes, there is a trick for draining the capacitor that holds power for the electronic control module stay alive memory when power is disconnected. As a Certified professional auto mechanic it's my duty to let you know what kind of problems are common when you perform this operation! 

Remember if you have a hard failure the light will come right back on. Consider pulling the codes and following available online factory that provide diagnostic charts for the specific code set. This is how professional mechanics solve car problems.

Another reason for not disconnecting the battery is that newer vehicles have a few installed options on-board that require constant battery voltage. I know what your thinking, what if you have to replace the battery or disconnect it for cleaning.

I personally use a device called a battery tender. This is plugged into the cigar lighter socket before you disconnect the power and ground cables to not only hold the radio station presets, clock settings but also keep the on-board memory alive for the power-train control module (PCM).


Reset check engine light complications


For example if you have a theft deterrent radio and you disconnect the battery your radio may stop working when reconnected. When the power is disconnected to reset the check engine lightthe cars radio might think that it is being stolen.

The radio can go into a self defense mode and not operate until a special code has been inputted. In most cases this special code is included in your owner's manual. Or was supplied by the dealer at the time of delivery.

This may not do you any good if you have purchased the automobile in question off a used car lot. Also note that if your vehicle is equipped with a factory installed car alarm or theft deterrent system disconnecting the battery may cause a few problems with this system as well. 

The owner’s or service manual may provide a special procedure for replacing the battery and disabling the alarm system before the battery is disconnected. Some car makers provide a built in sleep mode for just this operation.

Last but not least stored in the computer along with the code is the automobiles learned memory. This stores driving habits like shift points and IAC steps for idle control. The vehicle may have stalling and hard shifting problems for a while after the battery is reconnected. It will usually recover but it may take several drive cycles for this to happen.

An easier way to clear the check engine light codes is to use an auto scan tool. The automotive scanner comes with good documentation that will walk you through how to retrieve the codes and reset the check engine light.

They can do this without disconnecting the battery power or causing any of the problems mentioned above. One of the best selling automotive scanners right now at the time of this writing is the Actron. For people that want to keep it simple see the cheaper equus 3030.

Reset check engine light the hard way

If you decide that you have what you need to disconnect the battery and would like to reset the check engine light by doing so there are a few more tips that I can provide. Most vehicles from 1996 and newer have a stay alive memory built-in to the computer system.

When you disconnect the battery from the vehicle toreset the check engine light. The computer will be able to hold the memory and the code for several minutes and in some cases several hours.

Battery voltage is stored in a capacitor and is supplied to the computer to keep the internal memory alive. The way around this is to disconnect the battery and then hold down on the horn button. The horn circuit is one of only a few that is hot at all times (regardless of key position). This is why you can blow the horn without the ignition turned on. 

Holding down on the horn button will drain the small electrical current that is stored in the control modules capacitor. This will reset check engine light on most models.

As a side note, when you do this you will be erasing all memory associated with the computer as well. When you reconnect the battery on the vehicle and confirm the reset check engine light procedure has been successful, you may find that the engine idle may be erratic for several drive cycles. This is because the memory idle learn has also been erased along with your check engine light code. 

This problem is usually short-term and will correct itself after driving the vehicle for a few miles at highway speeds. Also note if the check engine light comes back on after this reset check engine light procedure you have a hard failure code. This is when a failure is constant and will need diagnosis.

So to review you do have a few options for resetting your check engine light, but the easiest way is to use an auto scan tool to clear the code.

How to check your oil

Instructions

Things You'll Need

• 1 Quart of Motor Oil
• Paper Towels
• Rags

1. • 1
     Park the car on a level surface.
   • 2
     To get the most accurate reading you want to check your oil when the engine is cold.
   • 3
     Pull the hood release lever under the dashboard.
   • 4
     
     

     Walk around the front of the car, reach under the hood, find the latch and squeeze it. As you squeeze the latch, open the hood.
   • 5
     
     

     Find the dipstick. This is a long piece of metal sticking out of the engine with a loop at one end, usually located near the center of the engine. Many times it will be labeled with the word "Oil" or brightly colored.
   • 6
     Pull on the loop and draw the dipstick all the way out.
   • 7
     
     

     Wipe the oil off the dipstick with a paper towel or shop rag.
   • 8
     
     

     Replace the clean dipstick, making sure to push it all the way in, then pull it back out and hold it horizontally in front of you.
   • 9
     
     

     Look at the pointy end of the dipstick. If the oil on the dipstick is below the line marked "full," add a small amount of oil. Many dipsticks simply have 2 lines with a cross hatch design in between. The oil level should be halfway between these 2 lines.
   • 10
     
     

     Add the oil by unscrewing the oil filler cap, which is about 3 inches in diameter and located on the very top of the engine. It will usually be marked with the words "Engine Oil".
   • 11
     Check the oil level with the dipstick after adding oil. Add more if necessary. It's easier to add more oil several times, then to take oil out.
   • 12
     Put the oil filler cap back on and secure it tightly.

Read more: How to Check Your Oil | eHow.com http://www.ehow.com/how_103_check-oil.html#ixzz1mVFxBzrR

Peugeot and Citroen check engine list / fault code / trouble code

P11XX - Fuel and Air Metering

P1100   MAF (Mass Air Flow) sensor intermittent / Systems check not complete

P1101   MAF (Mass Air Flow) sensor Out of self test range

P1102   MAF (Mass Air Flow) sensor in range but lower than expected

P1103   MAF (Mass Air Flow) sensor in range but higher than expected

P1104   MAF (Mass Air Flow) ground malfunction

P1105   Dual alternator upper fault

P1106   Dual alternator lower fault / MAP (Manifold Absolute Pressure) sensor circuit Intermittent high voltage

P1107   Dual alternator lower circuit malfunction / MAP (Manifold Absolute Pressure) sensor circuit Intermittent low voltage (EDC15C2-Swirl solenoid valve)

P1108   Dual alternator battery lamp circuit malfunction / Baro to MAP (Manifold Absolute Pressure) sensor comparison too high

P1109   Intake air temperature (IAT) B sensor intermittent

P1110   Intake air temperature (IAT) sensor (D/C) open/short.

P1111   Intake air temperature (IAT) sensor circuit Intermittent high voltage

P1112   Intake air temperature (IAT) sensor circuit Intermittent low voltage

P1113   Intake air temperature (IAT) sensor circuit open/short

P1114   Engine coolant temperature (ECT) sensor circuit Intermittent low voltage / IAT - B sensor circuit low input

P1115   Engine coolant temperature (ECT) sensor circuit Intermittent high voltage / IAT - B sensor circuit high input

P1116   Engine coolant temperature (ECT) sensor out of range

P1117   Engine coolant temperature (ECT) sensor circuit Intermittent

P1118   Manifold absolute temperature sensor circuit Low input

P1119   Manifold absolute temperature sensor circuit High input

P1120   Throttle position sensor (TPS) out of range

P1121   Throttle position sensor (TPS) circuit Intermittent high voltage

P1122   Throttle position sensor (TPS) circuit Intermittent low voltage

P1123   Throttle position sensor (TPS) In range but higher than expected

P1124   Throttle position sensor (TPS) Out of self test range

P1125   Throttle position sensor (TPS) circuit Intermittent

P1126   Throttle position sensor (TPS) circuit (Narrow range) Malfunction

P1127   Exhaust not warm Downstream oxygen sensor

P1128   Upstream heated oxygen sensor (HO2S) Swapped

P1129   Downstream heated oxygen sensor (HO2S) Swapped

P1130   Lack of HO2S switching - Adaptive fuel at limit

P1131   Lack of HO2S switching - Sensor indicates lean

P1132   Lack of HO2S switching - Sensor indicated rich  

P1133   HO2S 1 Insufficient switching

P1134   HO2S 1 Transition time ratio

P1135   Pedal position sensor circuit A Intermittent

P1136   Fan control circuit Malfunction

P1137   Lack of HO2S 2 switching - Sensor indicates lean

P1138   High pressure rail sensor fault / Lack of HO2S 2 switching - Sensor indicates rich

P1139   Water in fuel indicator circuit Malfunction

P1140   Water in fuel condition

P1141   Fuel restriction indicator circuit Malfunction

P1142   Fuel restriction Condition

P1143   Air assist control valve Range / Performance

P1144   Air assist control valve circuit Malfunction

P1145   Lucas DCN2 - Noise on the needle lift sensor. Incoherence

P1150   Lack of HO2S 21 switching - Adaptive fuel at limit

P1151   Lack of HO2S 21 switching - Sensor indicates lean

P1152   Lack of HO2S 21 switching - Sensor indicated rich

P1153   Bank 2 Fuel control shifted lean. MM6LP - Throttle stop learning. Malfunction

P1154   Bank 2 Fuel control shifted rich

P1155   Alternative fuel controller

P1156   Fuel select switch malfunction

P1157   Lack of HO2S 22 switching - Sensor indicates lean

P1158   Lack of HO2S 22 switching - Sensor indicates rich

P1159   Fuel stepper motor Malfunction

P1164   Fuel pressure sensor test

P1165   SID 803 - Fuel Pressure signal. Pressure change coherence.

P1167   Invalid test throttle not pressed (AL4 - Fault in pressure regulation - variation/recommendation)

P1168   Fuel rail sensor In range low failure

P1169   Fuel rail sensor In range high failure / EDC15C2-Condenser 1 voltage

P1170   Engine shut off (ESO) solenoid Fault / EDC15C2-Condenser 2 voltage

P1171   Rotor sensor Fault / EDC15C2-Engine stop test by injector cut-off

P1172   Rotor control Fault

P1173   Rotor calibration Fault

P1174   Cam sensor Fault

P1175   Cam control Fault

P1176   Cam calibration Fault

P1177   Synchronisation Fault

P1178   (open)

P1180   Fuel delivery system Malfunction - low

P1181   Fuel delivery system Malfunction - high

P1182   Fuel shut off solenoid Malfunction

P1183   Engine oil temperature circuit Malfunction

P1184   Engine oil temperature Out of self test range

P1185   Fuel pump temperature sensor (FTS) high

P1186   Fuel pump temperature sensor (FTS) low

P1187   Varient selection

P1188   Calibration memory fault

P1189   Pump speed signal Fault

P1190   Calibration resistor out of range

P1191   Key line voltage

P1192   Voltage external

P1193   EGR drive Overcurrent

P1194   ECU A/D converter

P1195   SCP HBCC Failed to Inititialise

P1196   Key off voltage high

P1197   Key off voltage low / Piezo-electric injector, power stage

P1198   Pump rotor control Underfuelling - SID801 - Diesel high pressure monitoring. Flow regulator at stop.

P1199   Fuel level Input circuit low