Operation CHARM: Car repair manuals for everyone.

DS1 - Check PSOM Resistance



Continuous Memory Diagnostic Trouble Code (DTC) 29 indicates that during the last 80 warm-up cycles, the Powertrain Control Module (PCM) detected an error in the Programmable Speedometer/Odometer Module (PSOM) output signal. DTC 452 indicates the PCM detected an error in the PSOM output signal during the last 40 warm-up cycles. Possible Causes:

- Damaged Rear Anti-Lock Brake System (RABS).

- Damaged PSOM.

- Damaged harness circuits.

- Damaged PCM.

- Key "OFF".

- Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- Measure resistance between test pin 3 and test pin 6 at the breakout box.

- Is resistance between 21,000 and 55,000 ohms?

Yes -- Go to DS4. DS4 - Check RABS Sensor Resistance

No -- Go to DS2. DS2 - Check Continuity of the Harness Circuit