|November 10th, 2005, 06:24 PM||#1|
Join Date: 11-03-05
Location: OC - MI
1991-1995 Wrangler trouble codes.
1991-1995 Jeep Wrangler (YJ) Trouble Codes
Code Probable Cause
Manifold Absolute Pressure (MAP) Sensor Vacuum
Manifold Absolute Pressure (MAP) Sensor Electrical
Distance sensor or circuit
Engine running too cool
Oxygen sensor or circuit
Coolant temperature sensor or circuit
MAT sensor or circuit
Throttle Position Sensor (TPS) sensor or circuit
Automatic Idle Speed (AIS) circuit
Fuel injector control
EVAP solenoid or circuit
Air conditioning clutch relay
Automatic shutdown relay
Battery temperature sensor
Battery over voltage
Battery under voltage
Oxygen sensor - lean condition
Oxygen sensor - rich condition
Internal engine controller fault
Distributor sync pickup
End of Code output
Emissions Maintenance Reminder (EMR) mileage accumulator
Controller failure EEPROM write denied
The diagnostic trouble codes on all models can be extracted from the Powertrain Control Module (PCM) using a SCAN tool. On 1991 through 1995 models only, the PCM can be placed in the diagnostic mode and the trouble codes flashed on the Check Engine light.
The PCM will illuminate the CHECK ENGINE light on the dash if it recognizes a fault in the system. The light will remain lit until the problem is repaired and the code cleared or the PCM does not detect any malfunction for several consecutive drive cycles.
To extract the diagnostic trouble codes, perform the following steps:
1. Without starting the engine, turn the ignition key ON, OFF, ON, OFF and ON. The CHECK ENGINE light on the dash will begin to flash.
2. If any trouble codes are stored in the PCM memory, the CHECK ENGINE light will flash the number of the first digit, pause and flash the number of the second digit. For example, Code 23, air temperature sensor circuit would be indicated by two flashes, pause three flashes. A long pause will appear between individual codes if more than one code is present. Carefully observe the flashes and record the exact code number(s) onto paper.
3. After the stored codes have been indicated (or if everything in the self diagnosis system is functioning properly), the CHECK ENGINE light will flash a Code 55.
4. If the ignition key is turned OFF during the code extraction process and possibly turned back ON, the self diagnostic system will automatically invalidate the procedure and must be restarted.