Jeep Diagnostic Trouble Codes OBD1
Step by step guide on how to retrieve trouble codes from Jeep vehicles made before 1995 Step 1 - Trouble codes are identified by a two digit code. To activate the code gathering sequence turn the ignition key on and off five times in rapid secession ending with the key in the "ON" position. This will start the code gathering, by watching the check engine light and counting the number of times it flashes. The first set of flashes will be the first digit of the trouble code. There will be a short pause and then start flashing again, count the number and that will be the second digit in the trouble code. For example if the first blink number is four and the second number blink is six the code number is 46. Step 2 - To restart the code gathering, turn the the ignition key to the off position and wait 5 minutes and start over. When the code gathering has been completed the system will flash a number fifty five which means the code display has ended. To clear codes after the repairs have been performed remove the negative battery cable and within two minutes and reconnect. Trouble Code Table 11 No crank reference signal 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 (atmospheric) pressure reading at start-up 14 MAP sensor below minimum acceptable voltage 15 No vehicle speed sensor signal detected 17 Engine coolant temperature below normal operating temperatures 21 Neither rich nor lean condition detected from the oxygen sensor 22 Engine coolant temperature sensor input above maximum acceptable voltage 23 Intake manifold air temperature sensor input above maximum acceptable voltage 24 Throttle position sensor input above maximum acceptable voltage 25 A short condition detected in the idle air control motor 27 Injector output driver does not respond properly to the control signal or injector 33 An open or shorted condition detected in the A/C clutch relay circuit 34 An open or shorted condition detected in the speed control vacuum or vent solenoid circuits 35 An open or shorted condition detected in the radiator fan relay circuit 41 An open or shorted condition detected in the generator field control circuit 42 An open or shorted condition detected in the auto shutdown relay circuit 44 An open or shorted condition exists in the engine coolant temperature sensor circuit 46 Battery voltage sense input above target charging voltage during engine operation 47 Battery voltage sense input below target charging voltage during engine operation 51 Oxygen sensor signal input indicates lean air/fuel ratio condition during engine operation 52 Oxygen sensor signal input indicates rich air/fuel ratio condition during engine operation 53 PCM internal fault condition detected 54 No fuel sync (camshaft signal) detected during engine cranking 55 Completion of diagnostic trouble code display on the malfunction indicator lamp (check engine lamp) 62 Unsuccessful attempt to update SRI (service reminder indicator) miles in the PCM EEPROM 63 Unsuccessful attempt to write to an EEPROM location by the PCM Helpful Information When you see a check engine light blink or stay on steady while you drive it means the computer has stored a diagnostic trouble code or codes. These codes are meant to help define a particular problem is the engine or emissions system.