P0703

WITH 4L60-E AUTOMATIC TRANSMISSION

DTC P0703 TCC Brake Switch Circuit - Malfunction:

TCC Brake Switch Circuit - Malfunction:

CIRCUIT DESCRIPTION
The Torque Converter Clutch (TCC) brake switch is used to indicate brake pedal status. The normally closed brake switch supplies a (B+) signal on CKT 420 to the Vehicle Control Module-A (VCM-A). The signal voltage circuit is opened when the brakes are applied. The VCM-A uses this signal to de-energize the TCC solenoid when the brakes are applied. DTC Type (D).

DTC P0703 WILL SET WHEN
The VCM-A detects a closed brake switch/circuit (12 volts) during vehicle de-acceleration and the following events occur for a total of seven times:
- Vehicle speed is greater than 20 MPH for 6 seconds; then vehicle speed is between 5 and 20 MPH for 6 seconds; then vehicle speed is less than 5 MPH.

-OR-

The VCM-A detects an open brake switch/circuit (0 volts) during vehicle acceleration and the following events occur for a total of seven times:
- Vehicle speed is less than 5 MPH; then vehicle speed is between 5 and 20 MPH for 6 seconds; then vehicle speed is greater than 20 MPH for 6 seconds.

ACTION TAKEN (VCM-A will default to)
An incorrect brake signal can affect TCC scheduling. Also, an incorrect brake signal can inhibit fourth gear operation, if in hot mode. DTC P0703 will be stored in VCM-A memory, but will not turn on the Malfunction Indicator Lamp (MIL).

DTC P0703 WILL CLEAR DEFAULT ACTION WHEN
Fault condition no longer exists and key is cycled "OFF" for five seconds, then "ON."

DTC P0703 WILL PASS WHEN
- VCM-A brake switch signal must indicate voltage for 5 seconds while brake is not on and must not indicate voltage (open) when brake is depressed for 5 seconds.
- All enable criteria are met.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic charts.
1. This test checks for voltage at the brake switch.
2. This test checks the brake switch.
3. This test checks CKT 420 at the VCM-A.

DIAGNOSTIC AIDS
- Refer to Intermittents.
- Check customer driving habits and/or unusual traffic conditions (i.e. stop and go, expressway traffic).
- Check brake switch for proper adjustment.
- Check for most current calibration I.D. and/or latest bulletins.