Diagnostic Aids

A Code 39 in conjunction with a Code 38 would mean a problem with one or more of the following components.

• Fuse or power circuit, brake switch or wire before the splice.

Code 39 alone indicates a problem at:

• Circuit No. 420 between splice and TCC solenoid.
• Circuit No. 422 between TCC solenoid and ECM.
• Poor connection to the ECM or ECM, itself.

Fig 1: Code 39, TCC Circuit Diagram (3.3L & 3.8L W/4T60 Transaxle)

Courtesy of GENERAL MOTORS CORP.