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
- Mass air flow sensor may be faulty
Tech notes
The P0171 is a very common code for the 2003 Ford Windstar. Here a link to a web site with information how to repair:
1999-2003 Fords Windstar Code P0171
When is the code detected?
- The amount of mixture ratio compensation is too large. (The mixture ratio is too rich.)
- Fuel injection system does not operate properly.
P0171 2003 FORD WINDSTAR Description
The Powertrain Control Module (PCM) monitors the engine Air/Fuel mixture ratio, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The PCM calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the PCM judges the condition as the fuel injection system malfunction and light up the engine light.
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Lack/loss of power
- Hard start
- Engine hesitation
Possible causes
- Improper spark plug at cylinder #2
- Insufficient compression at cylinder #2
- Incorrect fuel pressure
- The injector circuit is open or shorted at cylinder #2
- Fuel injector #2 may be faulty
- Intake air leak at cyli
Possible solution
- Perform Injector Service
- Replaced Spark Plug #2
- Replaced Injector #2
- Replaced Ignition Coil #2
When is the code detected?
- Engine Cylinder #2 is Misfiring.
P0302 Description
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, The Powertrain Control Module (PCM) or Engine Control Module (ECM) can determine that a misfire is occurring.
P0603 FORD - ECM Keep Alive Memory Test Error
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Engine may not start
Possible causes
- Loose or poor battery terminal connection
- Low battery charge
- ECM power supply circuit is open or shorted
- ECM Programing
- Faulty ECM
Possible solution
- Recharge battery
- Resecure and clean battery terminal connection
- Reprogram ECM
- Replaced ECM
Tech notes
Start by charging the vehicles battery and clean terminal, once the battery is charged and the terminals are clean and secure, erase code. If the code comes back ON you may have to reprogram or replaced ECM
When is the code detected?
Indicates the ECM has experienced an internal memory fault.
P0603 FORD Description
Battery voltage is supplied to the ECM even when the ignition switch is turned OFF for the ECM memory function of the DTC memory, the air-fuel ratio feedback compensation value memory, the idle air volume learning value memory, etc.