To get the codes from your 1991-1997 Jeep Wrangler:
1) Turn the ignition key ON THREE TIMES in succession:
ON : OFF : ON : OFF : ON
(within FIVE seconds)
2) Count the number of times the check engine lamp on the dash flashes. The number of flashes represents the error code. There will be a short pause between the flashes representing the different digits of the code. Longer pauses separate individual trouble codes.
3) Code 55 will be the last code to be displayed.
4) These codes will also be displayed on the odometer, where they are much easier to read. (TJ ONLY)
Code Description
11 - No crank reference signal detected during engine cranking.
- Intermittent loss of either camshaft or crankshaft position sensor.
- CKP sensor target windows have too much variation.
12 Direct battery input to PCM was disconnected within the last 50 Key-on cycles.
13 No difference recognized between the engine MAP reading and the barometric (atmosphere) pressure reading from start-up.
14 - MAP sensor input above or below acceptable voltage.
- 5 volt output to MAP sensor open.
15 No vehicle speed sensor signal detected during road load conditions.
17 - Engine did not reach operating temperature within acceptable limits.
- Engine does not reach 20º F. within 5 minutes with a vehicle speed signal.
21 - Upstream oxygen sensor response slower than minimum required switching frequency.
- Upstream oxygen sensor heating element circuit malfunction.
- Downstream oxygen sensor heating element circuit malfunction.
- Downstream oxygen sensor input voltage maintained above the normal operating range.
- Oxygen sensor voltage too low, tested after cold start. (Upstream or Downstream)
- Left oxygen sensor input voltage maintained above the normal operating temperature.
22 Engine coolant temperature sensor above or below acceptable voltage.
23 Intake air temperature sensor input above or below acceptable voltage..
24 - Throttle position sensor input above or below acceptable voltage.
- TPS signal does not correlate to MAP sensor.
25 - A shorted or open condition detected in one or more of the idle air control motor circuits.
- Actual idle speed does not equal target idle speed.
27 Injector 3, and/or 4, and/or 5, and/or 6 output driver does not respond properly to the control signal.
31 - An open or shorted condition detected in the A/C clutch relay circuit.
- Insufficient or excessive vapor flow detected during evaporative emission system operation.
33 An open or shorted condition detected in the duty cycle purge solenoid circuit.
34 - An open or shorted condition detected in the Speed Control vacuum or vent solenoid circuits.
- Speed control switch input below the minimum acceptable voltage.
37 Relationship between engine speed and vehicle speed indicates no torque converter clutch engagement. Auto. only.
37 - An open or shorted condition detected in the torque converter part throttle unlock solenoid control circuit. (3 speed auto RH trans. Only).
- Incorrect input state detected for the Park/Neutral switch. Auto. only.
41 An open or shorted condition in the generator field control circuit.
42 - An open or shorted condition detected in the auto shutdown relay circuit.
- An open condition detected in the ASD relay output circuit.
- An open or shorted condition detected in the fuel pump relay control circuit.
- An open circuit between PCM and fuel gauge sending unit.
- Circuit shorted to voltage between PCM and fuel gauge sending unit.
- No movement of fuel level sender detected.
43 Peak primary circuit current not achieved with maximum dwell time.
43 Misfire detected in one or more cylinders 1 thru 6. (4 and 6 cyls.)
44 Battery temperature sensor in voltage above or below acceptable range.
46 Battery voltage sense input above target charging voltage during engine operation.
47 Battery voltage sense input below target charging during engine operation. Also, no significant change detected in battery voltage during active test of generator output circuit.
51 A lean air/fuel mixture has been indicated by an abnormally rich correction factor.
52 A rich air/fuel mixture has been indicated by an abnormally rich correction factor.
53 PCM Internal fault condition detected.
54 No camshaft signal detected during engine cranking.
55 Completion of fault code display on Check Engine lamp.
63 Unsuccessful attempt to write to an EEPROM location by the PCM.
64 Catalyst efficiency below required level. (Same as code 72)
65 Power steering high pressure seen at high speed. (2.5L only)
72 Catalyst efficiency below required level. (Same as code 64)
77 Malfunction detected with poser feed to speed control servo solenoids.
To get the codes from your 1997-2007 Jeep Wrangler:
To see the codes you put the key into the ignition, push and hold down the odometer reset button, turn the key to RUN, then release the odometer reset button. When you do this you are rewarded with dancing number displays, the firmware version number, any error codes, then a diagnostic test of all the dash indicators and gauges. The gauges will, one by one, go through a calibration--the needles moving and stopping at major increments so you can check their alignment with the dial markings.
Output from the newer onboard diagnostics is easier to read now, as you get full 4-digits codes for much greater detail.
Code Description
P1192 Inlet Air Temp. Circuit Low
P1193 Inlet Air Temp. Circuit High
P1195 1/1 O2 Sensor Slow During Catalyst Monitor
P1196 2/1 O2 Sensor Slow During Catalyst Monitor
P1197 1/2 O2 Sensor Slow During Catalyst Monitor
P1198 Radiator Temperature Sensor Volts Too High
P1199 Radiator Temperature Sensor Volts Too Low
P1281 Engine Is Cold Too Long
P1282 Fuel Pump Relay Control Circuit
P1283 Idle Select Signal Invalid
P1284 Fuel Injection Pump Battery Voltage Out Of Range
P1285 Fuel Injection Pump Controller Always On
P1286 Accelerator Pedal Position Sensor Supply Voltage Too High
P1287 Fuel Injection Pump Controller Supply Voltage Low
P1288 Intake Manifold Short Runner Solenoid Circuit
P1289 Manifold Tune Valve Solenoid Circuit
P1290 CNG Fuel Pressure Too High
P1291 No Temp Rise Seen From Fuel Heaters
P1292 CNG Pressure Sensor Voltage Too High
P1293 CNG Pressure Sensor Voltage Too Low
P1294 Target Idle Not Reached
P1295 No 5 Volts To TP Sensor
P1296 No 5 Volts To MAP Sensor
P1297 No Change in MAP From Start To Run
P1298 Lean Operation At wide Open Throttle
P1299 Vacuum Leak Found (IAC Fully Seated)
P1388 Auto Shutdown (ASD) Relay Control Circuit
P1389 No Auto Shutdown (ASD) Relay Output Voltage At PCM
P1390 Timing Belt Skipped One Tooth or More
P1391 Intermittent Loss of CMP or CKP
P1398 Mis-Fire Adapter Numerator at Limit
P1399 Wait To Start Lamp Circuit
P1403 No 5 Volts To EGR Sensor
P1475 Aux. 5 Volt Output Too High
P1476 Too Little Secondary Air
P1477 Too Much Secondary Air
P1478 Battery Temp Sensor Volts Out of Limit
P1479 Transmission Fan Relay Circuit
P1480 PCV Solenoid Valve
P1482 Catalyst Temperature Sensor Circuit Shorted Low
P1483 Catalyst Temperature Sensor Circuit Shorted High
P1484 Catalytic Converter Overheat Detected
P1485 Air Injection Solenoid Circuit
P1486 Evap Leak Monitor Pinched Hose
P1487 Hi Speed Rad Fan CTRL Relay Circuit
P1488 Auxiliary 5 Volt Supply Output Too Low
P1489 High Speed Fan CTRL Relay Circuit
P1490 Low Speed Fan CTRL Relay Circuit
P1491 Rad Fan Control Relay Circuit
P1492 Battery Temperature Sensor Voltage Too High
P1493 Battery Temperature Sensor Voltage Too Low
P1494 Leak Detection Pump Switch or Mechanical Fault
P1495 Leak Detection Pump Solenoid Circuit
P1496 5 Volt Supply Output Too Low
P1498 High speed Rad Fan Ground CTRL Rly Circuit
P1594 Charging System Voltage Too High
P1595 Speed Control Solenoid Circuits
P1596 Speed Control Switch Always High
P1597 Speed Control Switch Always Low
P1598 A/C Pressure Sensor Volts Too High
P1599 A/C Pressure Sensor Volts Too Low
P1602 PCM Not Programmed
P1680 Clutch Released Switch Circuit
P1681 No I/P Cluster CCD/J1850 Messages Received
P1682 Charging System Voltage Too Low
P1683 Speed Control Power Relay Or Speed Control 12 Volt Driver Circuit
P1684 Battery Disconnected Within Last 50 Starts
P1685 Skim Invalid Key
P1686 No SKIM Bus Message Received
P1687 No Cluster Bus Message
P1688 Internal Fuel Injection Pump Controller Failure
P1689 No Communication Between ECM & Injection Pump Module
P1690 Fuel injection pump CKP Sensor Does Not Agree With ECM CKP Sensor
P1691 Fuel Injection Pump Controller Calibration Failure
P1693 DTC Detected In ECM Or PCM
P1694 No CCD Messages Received From ECM
P1695 No CCD/J185O Message From BCM
P1696 PCM Failure EEPROM Write Denied
P1697 PCM Failure SRI Mile Not Stored
P1698 No CCD Messages Received From PCM
P1719 Skip Shift Solenoid Circuit
P1740 TCC Or OD Solenoid Performance
P1756 Governor Pressure Not Equal To Target At 15–20 PSI
P1757 Governor Pressure Above 3 PSI When Request Is 0 PSI
P1762 Governor Pressure Sensor Offset Improper Voltage
P1763 Governor Pressure Sensor Voltage Too High
P1764 Governor Pressure Sensor Voltage Too Low
P1765 Trans 12 Volt Supply Relay Control Circuit
P1899 Park/Neutral Position Switch Stuck In Park or In Gear