1997 Jeep TJ Diagnostic Codes

If you’re having a check engine light in your 1997 TJ, here is a list of codes that will help you find out what the problem is.

To run the check and find out what error code(s) it’s outputting do this: Turn the key ON -> OFF -> ON -> OFF -> ON within 5 seconds. It will take a bit to run some checks and output any codes into your digital odometer readout.

If you have a 1998-2006 TJ, the chart for those codes are here.

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
  • Auto transmission only!
  • Relationship between engine speed and vehicle speed indicates no torque converter clutch engagement.
  • An open or shorted condition detected in the torque converter part throttle unlock solenoid control circuit.
  • Incorrect input state detected for the Park/Neutral switch.
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.
  • Misfire detected in one or more cylinders 1 through 6.
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 or 72
  • Catalyst efficiency below required level.
65
  • Power steering high pressure seen at high speed. (2.5L only)
72 or 64
  • Catalyst efficiency below required level.
77
  • Malfunction detected with poser feed to speed control servo solenoids.