OBDI (Pre '96) Codes
The current code list linked in FAQ is incomplete, so I'm writing up a new one...
To check the codes stored in the computer:
1. Cycle the ignition key ON-OFF -- ON-OFF--- ON within 5 seconds. To cycle the ignition key ON means to turn it only as far as it takes to get the radio to come on. It does not mean to turn the engine on.
2. Count the number of times the "check engine" lamp on the instrument panel flashes on and off. The number of flashes represents the code. There is a slight pause between the flashes representing the first and second digits of the code. Longer pauses separate individual codes. For example, flash-flash-flash [pause] flash-flash represents the code 32.
A code of "12" is generally accepted to represent the beginning of codes on our trucks.
A code of "55" represents end of codes. If this is all you get then no error codes are stored in the computer. This is the normal condition.
Code and description
11** Timing belt skipped 1 tooth or more from initial learned value, Intermittent loss of either camshaft or crankshaft position sensor, No crank reference signal detected during engine cranking
12* Direct battery input to PCM was disconnected within the last 50 key-on cycles (normal)
13** No change in MAP output voltage from start to run
14** MAP sensor output voltage outside the acceptable range (too low or too high)
15** No vehicle speed sensor signal
17* Closed loop temp not reached or engine cold too long
21** 02s sensor does not detect rich or lean condition (signal stays at center)
22** Engine coolant temp sensor signal outside the acceptable range
23** Intake air temp sensor signal outside acceptable range
24** Throttle Position sensor signal outside acceptable range
25** Idle air control motor circuit short or open condition detected
27* Injector control circuit failure
31** Evap Solenoid circuit short or open condition detected
32** EGR Solenoid circuit short or open condition detected
33* A/C clutch relay circuit short or open condition detected
34* Speed control vacuum or vent circuit short or open condition detected OR speed control switch input outside accepted range
35 Rad Fan control relay circuit short or open condition detected (4 cyl only)
37* Torque converter clutch solenoid CKT or park/neutral switch failure OR Transmission Temperature sensor to high, which is specific to Ram PCM 94-up Dakotas don't have the transmission temperature sensor.
41** Generator field not switching properly
42* Fuel pump relay control ckt, Auto shutdown relay control ckt, No ASD relay output voltage at PCM, Fuel level sending unit volts out of range, Fuel level unit No change over miles
43** Multiple/ single cylinder misfire
44* Battery temp sensor volts out of accepted range
45* Transmission OD solenoid circuit short or open condition detected
46** Charging system voltage too high
47** Charging system voltage too low
51** Fuel system lean
52** Fuel system rich
53* Internal PCM failure
54* No cam signal at PCM
55* End of error messages (If you get this only, no errors were found)
62* PCM failure SRI mile not stored
63* PCM Failure EEPROM write denied
64** Catalytic Converter Efficiency Failure
65 Power steering switch failure
Fault Codes with * - check engine lamp will not illuminate at all times if this code was recorded
Fault Codes with ** - Checking engine lamp will illuminate when the engine is running if this code was recorded
Last edited by Crazy4x4RT; 03-02-2012 at 06:32 PM.