Powertrain Controls - ECM/PCM

Code Chart 38:

TCC Circuit:

CIRCUIT DESCRIPTION:
The ECM monitors the status of the brake switch circuits through ECM terminal "BC4."

DTC 38 will set if:

^ No DTC 24 is present.
^ Vehicle speed has been above 35 mph and back to 0 mph 23 times.
^ Brake switch status has not changed from released to applied or applied to released.

DTC 38 does not illuminate the MIL light.

TEST DESCRIPTION:

1. Jumpering the brake switch will determine if the ECM and the wiring for the brake circuit are OK.

2. Verifies the voltage to the brake switch.

DIAGNOSTIC AIDS:
DTC 38 in combination with a DTC 39 would mean a problem with one or more of the following components. Fuse, CKT 639, brake switch or wire before the splice. A single DTC 38 is the result of a wire or CKT 420 problem between the splice and the ECM, poor connection to ECM connector, or possibly the ECM.