How to read the On Board Diagnostic OBD codes on a 1991-1995 Jeep Wrangler YJ.
Code Probable Cause
11 Ignition
13 Manifold Absolute Pressure (MAP) Sensor Vacuum
14 Manifold Absolute Pressure (MAP) Sensor Electrical
15 Distance sensor or circuit
17 Engine running too cool
21 Oxygen sensor or circuit
22 Coolant temperature sensor or circuit
23 MAT sensor or circuit
24 Throttle Position Sensor (TPS) sensor or circuit
25 Automatic Idle Speed (AIS) circuit
27 Fuel injector control
31 EVAP solenoid or circuit
33 Air conditioning clutch relay
41 Alternator field
42 Automatic shutdown relay
44 Battery temperature sensor
46 Battery over voltage
47 Battery under voltage
51 Oxygen sensor - lean condition
52 Oxygen sensor - rich condition
53 Internal engine controller fault
54 Distributor sync pickup
55 End of Code output
62 Emissions Maintenance Reminder (EMR) mileage accumulator
63 Controller failure EEPROM write denied
