Diagnostic Aids

A Code 38 in combination with a Code 39 would mean a problem with one or more of the following components. Fuse, circuit No. 439, brake switch or wire before splice. A singe Code 38 is the result of wire or circuit No. 420 problem between splice and ECM, poor connection to ECM connector or possibly the ECM.

Fig 1: Code 38, Troubleshooting Diagram (3.3L PFI N Body)

Courtesy of GENERAL MOTORS CORP.