Dear Sir/Madam: Would u pls let me know what possible causes, defects or problems would be when I get this sign on the panel: "SERVICE ENGINE SOON". Previously I wrote "CHECK ENGINE SOON". Sorry!!!!.

n the event of fuel pump "A" control circuit fault, a trouble code will be stored and a service engine soon lamp will be illuminated. Some models require multiple drive cycles (as many as 8) with a failure in order for the service engine soon lamp to be illuminated and others will activate it on the initial failure. The "A" refers to more of an area of malfunction as opposed to a particular circuit or component.

Symptoms

Symptoms may include a stored trouble code, an illuminated fuel cap malfunction lamp, and possibly an illuminated service engine soon lamp. If this code is stored, and a service engine soon lamp has not yet been illuminated, the code may be shown as pending.

Common Causes

The most likely cause of this code being stored is a defective fuel pump or relay. Most fuel pump control circuits are integrated into the PCM. Other causes may include corroded, open, or shorted wiring or connectors in the CAN Bus harness, a loose control module ground strap or broken ground wire, the CAN bus may also be defective

There are many possible causes of an engine stallng, however, The most likely cause of the symptoms you are describing would be a defective Idle Air Control Solenoid. (IAC).
It is located on the intake plenum near the throttle body and it looks like the picture below.

It could be a defective sending unit inside the tank, a defective fuel gauge/instrument cluster, or the MOST LIKELY cause would be a fuel gauge sending unit circuit that is shorted to ground.
The instrument cluster can be easilly diagnosed or eliminated as a possibility by connecting a scanner and accessing the Instrument Panel Cluster (IPC) and commanding the fuel gauge up and down with the computer. Also the IPC and/or Body Control module can be checked for fault codes that may lead to the cause of the problem. If the "Service Engine Soon" or "Service Vehicle Soon" light is on, you can BET that there are fault codes present. There also may be fault codes present that will not cause these lights to be illuminated. To be honest, a thorough scan of your entire onboard computer network is where I would BEGIN diagnosis.

P.S. I did do a search for Technical Service Bulletins (TSBs) related to your description of the problem and found none. This is not a common problem. (No published "quick-fixes")

The information below was complied by me, it explains what causes the check engine light to come on and the process of finding the cause.

When the Check Engine/Service Engine Soon light is turned on the computer control unit (called the PCM) has sensed a fault in the electronic controls of the engine and/or the emission system. When this happens you will seldom feel the car engine run any different. There are about 200 possible faults that turn the Check Engine light on, to know what has developed a problem you must have the system tested, this is called an OBD2 fault code test, Kragen and Autozone parts stores do this testing for free.

The information below was complied by me, it explains what causes the check engine light or Service Engine Soon light to come on and the process of finding the cause.

When the Check Engine light or Service Engine Soon light (depends on make) is turned on the computer control unit (called the PCM) has sensed a fault in the electronic controls of the engine and/or the emission system. When this happens you will seldom feel the car engine run any different. There are about 200 possible faults that turn the Check Engine light on, to know what has developed a problem you must have the system tested, this is called an OBD2 fault code test, Kragen and Autozone parts stores do this testing for free.

P0172 - Fuel Injection System Too Rich Bank 1 Symptoms - Engine Light ON (or Service Engine Soon Warning Light)
- Excessive Fuel Consumption Possible causes - Intake air leaks
- Front Heated oxygen sensor may be faulty
- Injectors may be faulty
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor may be faulty
- Incorrect PCV hose connec Possible solution Dirty air filter of faulty air flow sensor are common causes of the problem.

P0174 - Fuel Injection System Too Lean Bank 2 Symptoms - Engine Light ON (or Service Engine Soon Warning Light)
- Excessive Fuel Consumption Possible causes - Intake air leaks
- Front Heated oxygen sensor may be faulty
- Injectors may be faulty
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor may be faulty
- Incorrect PCV hose connection Possible solution Dirty air filter of faulty air flow sensor are common causes of the problem. Bottom line possible defective Mass airflow sensor and or O2 sensor in cylinder bank number two.

Dear Madam or Sir,

if the problem has an electrical cause, the oil temperature sensor is defective, this should be checked first.

If the sensor is working good, there is a mechanical problem with your transmission due to worn bushes and / or gaskets. The viscosity of the oil is decreasing while heating up, if there is a worn gasket the shift pressure drops and the transmission won´t shift.

Dear Madam or Sir,

this is a well known problem with the immobilizer system.

See the following official tech bulletin :

Affected vehicles:
All models with Bosch RB8 instrument panel up to 2002 MY.


Problem:

Engine starts and cuts out immediately.

Trouble code stored: 17978 (P1570) - engine control module (ECM), immobilizer active.

Trouble code stored: 18058 (P1650) - CAN data bus, instrumentation - no signal.


Cause
Immobilizer fault.
System arms when ignition switched ON.

Remedy:
Access fault memory. If trouble codes present fit modified instrument panel (incorporating immobilizer control module).

Note: Immobilizer can only be programmed using diagnostic equipment.

Hi. you can drive this vehicle around town for a while but, i wouldn't take it out to far away from the city. you don't want to get caught on an open interstate and lose the ecm. Here are some things you can check on during the troubleshooting process if you are doing it yourself.

1) Defective or corroded VSS connections
2) Maladjusted TPS sensor. The TPS should read about 0.42 volts at closed throttle
3) Defective speedometer cable
4) Bad or missing speedo drive gear(s) in tail shaft housing of the transmission
5) Defective VSS(possibility)
6) Defective ECM(possibility)

Please rate and god bless:)

THIS CAN BE CAUSED FROM ANYTHING FROM LEAVING THE GAS CAP LEAK CAUSING A EVAP EMISSIONS CODE TO A MODULE BAD TO A SENSOR IMPROPERLY READING YOU NEED TO GO TO A SHOP AND HAVE THE CODES PULLED THEN TAKE STEPS ON DIAG FROM THERE WITH OUT THEM YOUR IN THE DARK I HOPE THIS HELPS