Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 2. Lack of communication may be due to a partial malfunction of the Class 2 serial data circuit or due to a total malfunction of the Class 2 serial data circuit. The specified procedure will determine the particular condition.
- 3. A fuse failure will cause no communication this step has you check for this condition.
- 4. This step determines if the fuse blows due to a short to ground on the battery positive voltage circuit.
- 5. This step determines if there is a short to ground in the battery positive circuit causing the fuse to blow.
- 6. This step determines if any DTCs have set.
- 7. This step refers to the table for C0306 for further diagnosis if a transfer case mode change is causing the fuse to blow.
- 8. The presence of DTCs indicates that the transfer case shift control module has detected a fault. Go to symptoms for other concerns.
- 9. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
- 10. Vehicle speed is provided to the transfer case shift control module via Class 2 and can effect the setting of DTC C0300. Perform the diagnostics for powertrain DTCs P0502 and P0503 first.
- 11. Perform diagnostics for DTC C0300 and C0305 first before addressing other DTCs. DTC C0300 and C0305 can be responsible for setting other DTCs.