Jeep check engine codes for the Jeep Wrangler YJ and the XJ Cherokee. These codes and video may work with other OBD1 Jeeps.When Chrysler / Jeep came up with this idea for getting the engine codes, it was a very smart move. This generation of Wranglers and Cherokees had the most simple diagnostics of any other. You need no special scanner to get the trouble code. Just a series of light flashes and the little light becomes a trouble shooting narc!! Below is the list of all the various Jeep check engine codes that the on-board computer can generate. At the bottom of the page is a YouTube video of how to get the trouble codes from Jeep PCM. Want a clean printable copy of the Engine codes ... Using the ignition switch, at no point do you actually start the Jeep: Start with the ignition in the OFF position, *= Check Engine light will not illuminate at all times if this Trouble Code it present. **= Check Engine light will illuminate during engine operation if this Trouble Code is present. 

Diagnostic trouble code and descriptions: 11*: No crank reference signal detected during cranking. Timing belt skipped one or more teeth; or intermittent loss of either camshaft or crankshaft position sensor 12*: Battery or computer recently disconnected within the last 50 start cycles). This is a very common code. Will not trigger a "Check engine light". 13**: No change in Manifold Absolute Pressure sensor (MAP) from start to run.14**: MAP sensor voltage too high or too low. 15**: No speed sensor signal detected. 17*: Engine stays cold too long. Bad thermostat or temp sensor. 21**: Oxygen sensor detection neither rich or lean -or- 21**: Oxygen sensor input voltage stayed above normal operating range. 22**: Coolant temperature sensor signal above or below acceptable voltage. 23**: Intake air temperature sensor signal above or below acceptable voltage. 24**: Throttle position sensor signal above or below acceptable voltage. 25**: Automatic Idle Speed (AIS) motor driver circuit shorted.27*: One of the Injectors output drivers does not respond properly to control signal. 

33*: Air conditioning clutch relay circuit open or shorted. If your Jeep doesn't have AC you will always get this code. 34*: Speed control vacuum or vent solenoid circuits open or shorted. hissing noise from outside ac unitSwitch is above or below acceptable voltage.35*: (XJs only) Cooling fan relay circuit open or shorted.37: Relationship between engine speed and vehicle speed indicates no torque converter clutch engagement. delonghi wall mounted air conditioning unitsAn open or shorted condition detected in the torque converter part throttle unlock solenoid control circuit. car air conditioning repair mariettaIncorrect input state detected for the Park/Neutral switch. 41**: Alternator field control circuit open or shorted.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. Misfire detected in one or more cylinders 1 thru 6. (4 and 6 cyls).44*: Open or shorted condition in the engine coolant temp sensor circuit or a problem exists in the PCMs battery temp voltage circuit.  46**: Battery voltage too high during charging.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 rich 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 module internal problem. 

55*: PCM has finished telling you the codes. This means you are done reading codes. 62: EMR mileage cannot be stored in EEPROM.62: PCM failure SPI mile not stored.63*: Controller cannot write to EEPROM.64: Catalytic converter efficiency failure.65: Power steering switch failure.  ****This information was gotten from the Chrysler FSM, Quadratec & various posts on WranglerBoard forum. So, I can’t and will not promise or guarantee it’s complete accuracy. Diagnosing trouble codes and changing parts can still be like chasing a needle in a haystack. But, it’s always a good place to start. Click here for a clean printable copy of the Jeep Check Engine Codes.On 1991 to1997 models ( 1984 to 1986 V6 models as well as 1998 to 2002 follow ) you have a way of reading for fault codes which can be accessed without any scanners like other models by reading how the check engine light flashes. Start by turning the ignition key to the last stop before it starts, on and off three

times within 5 seconds ending in the on position on the third time, ( i.e. on, off, on, off then on and leave ), ( OBDII 96-97, 4 times ) . The check engine light will start to flash quickly with a small pause in between then a medium pause to indicate the next number in the to digit number and then a long pause before the next set of flashing for the next code. If all is well you will get a code 55 which would read like this: 5 fast flashes, medium pause then aThis is how all codes end with is this 55 code if you have air conditioning or with a code 33 without and any other codes would have been before it separated by a long pause. The codes will remain after this test so you can cycle through it as many times as it takes to read them. After a problem has gone the code will be removed after 50 on off key cycles or if the battery left disconnected over night which will cause a code 12 though. On 1984 to 1986 V6 only models the codes can also be read.

First locate the diagnostics connector which is on the left fender well and is divided into two sections with six in the lower section ( 3 rows of 2 ) and fifteen in the upper section ( 3 rows of 5 ). In the upper section you have to run a wire between terminal six ( first row 4 down from the top ) and terminal 7 ( third row 3 down from the top ). turn the key into the on position making sure not to start it while these terminals are connected at any time. It should flash the code 12 ( 1 flash, pause, 2 flashes ) three times in a row and will repeat this sequence until disconnected if no other codes areIf there are any faults stored then they will follow afterwards repeating themselves three times before moving on to the next code. To clear to codes remove negative cable for 10 seconds or longer. For the 1998 to 2002 models you can access the trouble codesInsert the key but do not turn. Fully depress the trip reset button and holdNext turn the key to the on position three times and then leave in the on position.