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Getting and Using Chrysler, Plymouth, and Dodge Computer Codes
Originally from the Mopar Mailing List. "From Herb with additions by Charles Hobbs." Updated / modified by Allpar.
Getting the codes
If you have fuel injection, this works on most Chrysler, Plymouth, and Dodge cars made in the 1980s and 1990s.
- 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 (pause) FLASH FLASH FLASH (loong pause)
- It will never flash more than 9 times, watch for pauses!
- 55 is end of codes, 33 is normal on earlier models if you don't 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. Most of it comes from the Mopar Mailing List.
- * Activates Power Limited/Check Engine light on some models.
On newer cars (mid-to-late 1990s, 2000s):
- On later models with a digital odometer, the codes may be displayed on the odometer rather than blinking the check engine light. (This is the case on Peter Galambos' 1997 Dakota).
- On 1995 and later Neons, and probably other Chrysler, Plymouth, Dodge, and Jeep models, when the check engine light goes on, you may be able to get the codes simply by putting in the key and moving it to the RUN position; the light will blink out the codes without all that OFF-ON stuff. This will not work if the check engine light is not already on.
- Simultaneously press the trip reset and trip/odometer switches; while holding them, turn the ignition to RUN (not start), and wait about five seconds. This sends the car through a short self-test sequence that ights all segments of the odometer and shift selector read-out (where applicable). It will then display the stored error codes. (Courtesy Theodore M. Farabee of the U.S. Navy)
- On Elko Tchernev's 1998 Stratus, where there is only one combined trip/odometer and reset switch, waiting for 5 seconds will just reset the trip odometer. The procedure that does something is a little different:
- Press the switch, turn the ignition to ON, and release the switch as soon as the odometer displays "Check 1". This causes the computer to go through several check sequences (5, IIRC), for all lamps, LED segments and gauges, indicated by "Check 2" etc. and terminated by "End".
Note: When the computer indicates major failure, it will activate Limp In mode, which guesses about data to compensate for sensor failure. This is a nice feature not used by all automakers.
If you don't find your code in this list, try clicking here for a different site's lists.
- 11 No ignition reference signal detected during cranking (bad Hall effect) OR timing belt skipped one or more teeth; OR loss of either camshaft or crankshaft position sensor
- 12 Battery or computer recently disconnected
- 13* MAP sensor or vacuum line may not be working
- 14* MAP sensor voltage below .16V or over 4.96V
- 15 No speed/distance sensor signal
- 16* Loss of battery voltage detected with engine running
- 17 Engine stays cool too long (bad thermostat or coolant sensor?)
- 17 (1985 turbo only): knock sensor circuit
- 21 Oxygen sensor signal doesn't change (stays at 4.3-4.5V). Probably bad oxygen sensor
- 22* Coolant sensor signal out of range - May have been disconnected to set timing
- 23* Incoming air temperature sensor may be bad
- 24* Throttle position sensor over 4.96V (SEE NOTE #3)
- 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 (need to check computer signals, voltage reg, injectors) (SEE NOTE #4 BELOW)
- 27 Injector circuit isn't switching when it's told to (TBI)
OR (MPI) injector circuit #1 not switching right
OR (turbo) injector circuit #2 not switching right
OR (all 1990-) injector output driver not responding
- check computer, connections
- 31 Bad evaporator purge solenoid circuit or driver
- 32 (1984 only) power loss/limited lamp or circuit
- 32 EGR gases not working (1988) - check vacuum, valve
- 32 (1990-92, all but Turbo) computer didn't see change in air/'fuel ratio when EGR activated - check valve, vacuum lines, and EGR electrical
- 33 Air conditioning clutch relay circuit open or shorted (may be in the wide-open-throttle cutoff circuit)
- 34 (1984-86) EGR solenoid circuit shorted or open
- 34 (1987-1991) speed control shorted or open
- 35 Cooling fan relay circuit open or shorted
- 35 (trucks) idle switch motor fault - check connections
- 36 (turbo) Wastegate control circuit open or shorted
- 36 (3.9/5.2 RWD) solenoid coil circuit (air switching)
- 36 (Turbo IV) #3 Vent Solenoid open/short
- 37 Shift indicator light failure, 5-speed
part throttle lock/unlock solenoid driver circuit (87-89)
solenoid coil circuit (85-89 Turbo I-IV)
Trans temperature sensor voltage low (1995 and on; see NOTE 2)
- 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
- 42 Z1 voltage missing when autoshutdown circuit energized (SEE NOTE #6)
- 43 Peak primary coil current not achieved with max dwell time
- 43 Cylinder misfire
- 43 Problem in power module to logic module interface
- 44 No FJ2 voltage present at logic board
- 44 Logic module self-diagnostics indicate problem
- 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 (lean condition)
- 51 Internal logic module fault ('84 turbo only)
- 52 Oxygen sensor stuck at rich position (SEE NOTE #5!)
- 52 Internal logic module fault ('84 turbo only)
- 53 Logic module internal problem
- 54 No sync pickup signal during engine rotation (turbo only)
- 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
- 88 Start of test (not usually given, don't expect it)
The power module has an air-cooled resistor which senses incoming air temperature. The logic modules uses this information to control the field current in the alternator. This code applies ONLY to alternators whose voltage is computer regulated. If you lose the feed to keep RAM information stored when the engine's off, you also lose battery voltage sensing. -- Bohdan Bodnar
From the 1995 TRUCK manuals: the trailer towing package includes a transmission coolant temp sensor while the standard package doesn't. This may cause the low (no) voltage indication. -- J.E. Winburn
Matt Rowe comments: The throttle postion circuit tells the computer how far the accelerator is depressed. The Throttle Position Sensor (TPS) is on the throttle body on the opposite side of the throttle cable. The connector should have a round rubber cover over the connections. Clear the fault codes, start the car and try jiggling the wires/connectors to try to trip a fault code. Loss of this signal could cause other problems.
During cranking, the computer will test the current through the injector to see whether there's too much resistance in the injector's path. If there is, code 26 is set.
The problem may be cured with tuner cleaner on the connectors.
For TBI engines, the injector's cold resistance should be between 0.9 and 1.2 ohms (specs vary with year). This is a peak-and-hold injector. With the engine idling the peak period should be about 1.2 milliseconds whereas the hold period will vary. If it's lower than this at idle, then the injector's shorted or there's a defect in the injector driver circuit. (Bohdan Bodnar)
Wade Goldman wrote: In my case, the breather tube leading into the catalytic converter had rusted and become detached. This some how would cause the sensor to read an over rich condition and run crummy. I did not trust the reliability of the weld over a corroded surface and opted for the more expensive route of replacing the converter, breather tube and all.
The Z1 voltage is the voltage of the circuits fed by the autoshutdown relay. This typically includes fuel pump and switched-battery feed to the ignition coil(s). In my Le Baron, the Z1 circuit leaves the power module and splits into two paths: the fuel pump and the positive side of the ignition coil. Internal to the power module is the auto shutdown relay (in my case, it's a sealed box about 1" by 1"). The output voltage is monitored to determine whether the relay responds correctly. I suspect that the ASD relay (and, therefore, the Z1 circuit) also feeds the fuel injector(s) driver(s) and current sensing circuit, but can't prove this.
I've used the Z1 voltage to test for good power connections to the power module. I connected my OTC 500 multimeter from the battery's positive post to the ignition coil's switched battery terminal and measured the voltage drop using the bar graph to monitor peak voltages. Voltage spikes of around 200 mV to 300 mV are ok -- anything more means tv tuner cleaner time (or replacing the power module). Another thing to check is the maximum voltage drop during the priming pulse. With the old power module, I was losing about 2 volts across the circuit; the replacement is losing about 1/4 volt. (Thanks, firstname.lastname@example.org)
Chrysler, Plymouth, Dodge, and Jeep car, minivan, and truck computer fault codes: how to get them and what to do with them. Good for sensor and other troubleshooting.