DTC U0100: Lost Communication with ECM / PCM "A"; DTC U0129: Lost Communication with Brake System Control Module; DTC U0293: Lost Communication with HV ECU [10/2015 - ]: Description

The hybrid vehicle control ECU communicates with the ECM and skid control ECU (brake booster with master cylinder assembly). When the hybrid vehicle control ECU assembly does not receive data from the ECM or skid control ECU (brake booster with master cylinder assembly), the hybrid vehicle control ECU assembly stores DTC U0100 or U0129.
The ECM communicates with the hybrid vehicle control ECU assembly. When the ECM does not receive data from the hybrid vehicle control ECU assembly, the ECM stores DTC U0293.
The skid control ECU (brake booster with master cylinder assembly) communicates with the hybrid vehicle control ECU assembly. When the skid control ECU (brake booster with master cylinder assembly) does not receive data from the hybrid vehicle control ECU assembly, the skid control ECU (brake booster with master cylinder assembly) stores DTC U0293.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
U0100	Lost Communication with ECM / PCM "A"	The hybrid vehicle control ECU assembly does not receive data from the ECM.	Open or short in sub bus 15 main line or connector Open or short in sub bus 15 branch line or connector Power source circuit of hybrid vehicle control ECU assembly Hybrid vehicle control ECU assembly Power source circuit of ECM ECM Open or short in CAN No. 6 junction connector	As there is no sub bus monitor ECU for sub bus 15, each ECU detects communication stops and stores DTCs.
U0129	Lost Communication with Brake System Control Module	The hybrid vehicle control ECU assembly does not receive data from the skid control ECU (brake booster with master cylinder assembly).	Open or short in sub bus 15 main line or connector Open or short in sub bus 15 branch line or connector Power source circuit of hybrid vehicle control ECU assembly hybrid vehicle control ECU assembly Power source circuit of skid control ECU (brake booster with master cylinder assembly) Skid control ECU (brake booster with master cylinder assembly) Open or short in CAN No. 6 junction connector	As there is no sub bus monitor ECU for sub bus 15, each ECU detects communication stops and stores DTCs.
U0293	Lost Communication with HV ECU	The ECM does not receive data from the hybrid vehicle control ECU assembly. The skid control ECU (brake booster with master cylinder assembly) does not receive data from the hybrid vehicle control ECU assembly.	Open or short in sub bus 15 main line or connector Open or short in sub bus 15 branch line or connector Power source circuit of ECM ECM Power source circuit of hybrid vehicle control ECU assembly Hybrid vehicle control ECU assembly Power source circuit of skid control ECU (brake booster with master cylinder assembly) Skid control ECU (brake booster with master cylinder assembly) Open or short in CAN No. 6 junction connector	As there is no sub bus monitor ECU for sub bus 15, each ECU detects communication stops and stores DTCs.

HINT:

This diagnosis procedure is for when DTC U0100, U0129 and U0293 are output at the same time.