Diagnostic Aids
A Code 39 in conjunction with a Code 38 would mean a problem with one or more of following components:
- Fuse or power circuit, brake switch or wire before splice.
Code 39 alone indicates a problem at:
- Brake input circuit between splice and TCC solenoid.
- TCC drive circuit between TCC solenoid and ECM.
- Poor connection to ECM or ECM itself.