Diagnostic Aids

A Code 38 in conjunction with a Code 26 would mean a problem with one or more of following components:

• Fuse or power supply circuit, brake switch or wire before splice.
• Code 38 alone is result of a wire or circuit problem between splice and control module, poor connection to control module, or possibly control module itself. If brake switch has failed in an open state, TCC will not engage. When code is set TCC will not engage and PCM will not allow 4th gear. Code 38 does not turn on SERVICE ENGINE SOON light on all models.

Fig 1: Code 38, Schematic, Brake Switch Circuit 3.8L

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 38, Flow Chart, Brake Switch Circuit 3.8L

Courtesy of GENERAL MOTORS CORP.