C1238

DTC C1238: Brake Thermal Model Exceeded:

DTC C1238 Schematic:

CIRCUIT DESCRIPTION
The Electronic Brake/Traction Control Module (EBTCM) monitors vehicle speed deceleration, ABS/TCS activation, and brake lamp ON times to calculate brake rotor temperatures. When brake rotor temperatures are exceeded, TCS is disabled, Diagnostic Trouble Code (DTC) C1238 is set, and the TRACTION OFF message is displayed. If brake usage is reduced during driving, brake rotor cooling is calculated and TCS is reenabled.

CONDITION FOR SETTING THE DTC
DTC C1238 could be set when either driven wheel estimated brake rotor temperature exceeds 375° C (700° F). If either driven wheel estimated brake rotor temperature has exceeded 375° C (700° F) during ABS or normal braking conditions, the code will not be set until the next TCS activation occurs. The code will not be set and TCS will not be disabled if both rotor estimated temperatures have cooled below 275° C (530° F) before the next TCS activation. If either driven wheel brake rotor temperatures has exceeded 375° C (700° F) during TCS then the code will be set immediately, but TCS will not be disabled until the end of the TCS event.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, TCS is disabled and the TRACTION OFF message is displayed.

CONDITIONS FOR CLEARING THE DTC
Condition for DTC is no longer present and scan tool clear function is used. Fifty start cycles have passed with no DTCs detected.

DIAGNOSTIC AIDS
The temperature are an estimated figure calculated by the EBTCM.
Possible causes:
- Excessive brake usage
- Excessive TCS usage
- Stoplamp/Brake Transaxle Shift Interlock (BTSI) Switch misadjusted or damaged.
- The temperature values are an estimated figure calculated by the EBTCM.

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
[3] Reads TCS status.