Chart A
Code Chart P039:
PCM Voltage Check:
NOTES ON FAULT TREE
1. Chart "A" checks for a TCC brake switch or wiring fault. PCM input PI71 should cycle from "HI" to "LO" to "HI" if there is no problem. If PI71 does cycle and the transmission test box brake led is "OFF," check the test box for proper connection.
2. To adjust the brake switch, first fully seat switch in its retainer, then pull up on brake pedal.