Code 123 - Pcm-To-EBTCM Delivered Torque Circuit Malfunction (With TCS): Notes
The Traction Control System (TCS) uses the ABS in conjunction with PCM fuel and ignition controls to limit drive wheel slippage during acceleration. The PCM controlled portion of the TCS reduces engine torque by altering spark timing and controlling throttle position. EBTCM sends a spark retard request to PCM via the Pulse Width Modulated (PWM) signal requesting the desired spark level for proper traction control system operation. The PCM then provides a throttle position PWM signal informing EBTCM what the actual throttle position of engine is.
Code 123 sets when there is a malfunction in the throttle position circuit or if signal is out of range. TCS is disabled at the end of current TCS cycle and TCS warning light is illuminated.
NOTE:
Test numbers refer to numbers on diagnostic chart. Use only 10-megohm (minimum) DVOM for all voltage and resistance tests. For identification of circuits and terminals referenced in charts and text, see WIRING DIAGRAMS .
- Checks to determine if delivered torque frequency and throttle angle are within specified ranges.
- Checks to determine if delivered torque frequency and throttle angle indicate a possible malfunctioning PCM. Checks for proper voltage at PCM terminal.
- Checks for proper voltage at PCM terminal.
- Checks for short to voltage between PCM and EBTCM terminals.
- Ensures malfunction was not due to physical damage of circuit.
- Checks for open in circuit between PCM and EBTCM terminals.
- Checks for short to ground in circuit between PCM and EBTCM terminals.
- Checks for possible poor terminal contact at EBTCM.