Tech - Trip Odometer Resets (Install Diode)

Some customers may comment that the trip odometer resets to zero.

The CNG vehicle's fuel system electrical components back feed, with 12 volts, Circuit #1020 for several seconds after key off. This voltage disrupts communication between the PCM and the I/P cluster and the trip odometer mileage information is lost before it is stored in the memory of the PCM.

Install the diode assembly, P/N 52369504, using the following procedure:

1. Remove the secondary lock (comb) from the diode assembly and save for reuse.



2. Find the grey 10 way connector (1), located between the radiator and where the radiator hose attaches to the engine.
3. Separate the grey 10 way connector and remove the comb from the connector top half (the one with the female terminals).
4. Using the terminal removal tool, GM 12094429, remove the pink wire from cavity C of the grey 10 way connector.
5. Insert the pink wire, removed in the previous step, into cavity B of the diode assembly connector and reinstall the comb.
6. Insert the pink wire from cavity C of the diode assembly into cavity C of the 10 way connector and reinstall the comb.
7. Reconnect both halves of the 10 way connector.
8. Attach the diode assembly to the side of the 10 way connector, using a plastic tie strap or tape.
9. Remove the ground stud nut from the top forward transaxle to the engine mounting bolt and slip the diode assembly wire eyelet over the stud and reinstall the nut.

Tighten
Tighten to 25 N·m(18 lb ft).

Parts are currently available from GMSPO.

For vehicles repaired under warranty, use: