DTC C1203/53 ECM Communication Circuit Malfunction: Description

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

The circuit is used to send TRAC & VSC control information from the skid control ECU (TRC+, TRC-) to the translate ECU, and engine control information from the translate ECU to the skid control ECU (ENG+, ENG-).

DTC DETECTION CONDITION CHART

DTC No.	DTC Detection Condition	Trouble Area
C1203/53	Both of following conditions are met: IG1 voltage is 9.5 V or more, and condition that signals cannot be transmitted to translate ECU occurs continuously for 5 seconds or more IG1 voltage is 9.5 V or more, and condition that signals cannot be received from translate ECU occurs continuously for 5 seconds or more	TRC +- communication line ENG +- communication line Skid control ECU Translate ECU