Diagnostic Codes

From the Chrysler FAQ

Start with the ignition off. Within five seconds, switch the key on,
off, on, off, on. (On is not start!)

The "check engine" light will flash. Count the flashes
Each code is a two digit code, so a (for example) 23 would be
FLASH FLASH  FLASH FLASH FLASH 

It will never flash more than 9 times, watch for pauses!

55 is end of codes, 33 is normal if you dont have air conditioning.

Please note that some codes are NOT included below, this
is not a complete listing, but it IS very close to complete.

88  Start of test (This only appears on DRBII, it's not blinked out)
11  No ignition reference signal detected during cranking (bad hall
    effect)
    OR timing belt skipped one or more teeth; or intermittent
    loss of either camshaft or crankshaft position sensor
12  Memory Standby power lost (battery cable disconnected)
13* No change in MAP from start to run
14* MAP sensor circuit open or shorted; voltage too low
15  No speed/distance sensor signal
16* Loss of battery voltage detected with engine running
17  Engine stays cold too long (bad thermostat)
21  Oxygen sensor signal out of range, possibly shorted
22* Coolant sensor signal out of range (or disconnected to set timing)
23  Intake air temperature signal out of range
24* Throttle position circuit out of range
25  Automatic Idle Speed (AIS) motor driver circuit shorted
    or target idle not reached, vacuum leak found
26  Peak injector circuit voltage has not been reached
27  Logic module fuel circuit internal problem
                OR
27  TBI injector does not respond properly to control signal
31  Evaporator Purge solenoid circuit open or shorted OR
     Evaparator solenoid circuit
32  EGR system failure OR
      Power loss lamp open or shorted
33  Air conditioning clutch relay circuit open or shorted
34  Speed control vacuum or vent solenoid circuits open or shorted
35  Cooling fan relay circuit open or shorted
36  Wastegate control circuit open or shorted
37  Shift indicator light failure, 5-speed (blown bulb) OR
    Park/neutral switch failure
                OR
37  Torque converter unlock circuit open or shorted, A-413 4-speed auto
41* Alternator field control circuit open or shorted
42  Automatic shutdown relay circuit open or shorted
42  Fuel pump relay control circuit
42  Fuel level unit - no change over miles
                OR
42  Z1 voltage missing when autoshutdown circuit energized (whatever
    that means)
43  Peak primary coil current not achieved with max dwell time
                OR
43  Cylinder misfire
43  Problem in power module to logic module interface
44  No FJ2 voltage present at logic board
                OR
44  Logic module self-diagnostics indicate problem
                OR
44  Battery temperature out of range (see Note #1!)
45  Turbo boost limit exceeded (engine was shut down by logic module)
46* Battery voltage too high during charging or charging system
    voltage too low
47  Battery voltage too low and alternator output too low
51  Oxygen sensor stuck at lean position
                OR
51  Internal logic module fault ('84 turbo only)
52  Oxygen sensor stuck at rich position
                OR
52  Internal logic module fault ('84 turbo only)
53  Logic module internal problem
54  No sync pickup signal during engine rotation (turbo only)
                OR
54  Internal logic module fault ('84 turbo only)
55  End of codes
61  "Baro" sensor open or shorted
62  EMR mileage cannot be stored in EEPROM
62  PCM failure SRI mile not stored
63  Controller cannot write to EEPROM
64  Catalytic converter efficiency failure
65  Power steering switch failure

* Activates Power Limited/Check Engine light.

  These codes cover multiple years and engines (2.2l, 2.5l,
3.0l). NOTE #1. The power module has an air-cooled resistor which
is used to sense the incoming air temperature.  This information
is fed to the logic module and is used to control the duty cycle
of the field current in the alternator.  This code applies ONLY
to alternators whose voltage is computer regulated.  The battery
voltage is sensed by the logic module -- there is an internal
takeoff from the wire feeding the NVRAM keep-alive power circuit
which is fed to a voltage comparator.  So...if you lose the feed
to keep RAM information stored when the engine's off, you also
lose battery voltage sensing.

    -- Bohdan Bodnar