Code 39, With 3T40 Trans. TCC Circuit Using Tech 1: Notes

Code 39 will set when no Code 28 is set, brake is not applied, TCC is commanded by ECM, transmission is in high gear and engine speed-to-vehicle speed ratio does not indicate TCC has engaged. All these conditions must have been met for more than 15 seconds.

1. Tests TCC power supply (GAGES fuse) and brake switch.
2. Tests ECM for proper operation.
3. Tests internal transaxle switches.