DTC U0100, U0122 (Body Control Module (Without CAN Gateway))

DTC U0100  : BCM (Body Control Module) Lost Communication with ECM/PCM DTC U0122  : BCM (Body Control Module) Lost Communication with VSA/ABS

NOTE: 

• If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .
• Before you troubleshoot, review the general troubleshooting information .
• According to the detected DTC (s), check for the power circuit and the ground circuit of the control unit which cannot communicate with the body control module.
• Refer to the DTC shown on the display, then inspect the connectors and terminals based on the instructions.

DTC (Body Control Module)

1. Problem verification

   -1. Clear the DTCs with the HDS.

   -2. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

   -3. Check for DTCs with the HDS.

   DTC Description	DTC
   U0100 BCM (Body Control Module) Lost Communication with ECM/PCM
   U0122 BCM (Body Control Module) Lost Communication with VSA/ABS

   Are any DTCs indicated?

   YES 

   Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Check for loose or poor connections.

2. Open wire check (F-CAN A H line, F-CAN A L line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the receiving control unit connector.

   Body control module connector B (36P)

   -3. Disconnect the transmitting control unit connector (s).

   Refer to the DTC shown on the display, then disconnect the connector (s) based on the instructions (see chart below).

   U0100: Jump the SCS line with the HDS, and wait more than 1 minute.

   DTC	Connector
   U0100	PCM connector A (50P)
   U0122	VSA modulator-control unit 46P connector

   -4. Check for continuity between the receiving control unit and the transmitting control unit on the F-CAN A H circuit and the F-CAN A L circuit.

   Test condition

   Vehicle OFF (LOCK) mode Body control module connector B (36P): disconnected Transmitting control unit connector (s) for indicated DTCs: disconnected

   DTC	Circuit name	Receiving control unit		Transmitting control unit
   		Connector	Terminal	Connector	Terminal
   U0100	F-CAN A H	Body control module connector B (36P)	No. 22	PCM connector A (50P)	No. 11
   	F-CAN A L		No. 23		No. 10
   U0122	F-CAN A H	Body control module connector B (36P)	No. 22	VSA modulator-control unit 46P connector	No. 20
   	F-CAN A L		No. 23		No. 21

   Is there continuity?

   YES 

   The F-CAN A H wire and the F-CAN A L wire are OK. Refer to the DTC shown on the display, then substitute or replace the control unit based on the instructions (see chart below).

   DTC	Operation for transmitting control unit
   U0100	Substitute a known-good PCM , then recheck. If DTC U0100 goes away after substitution, replace the original PCM .
   U0122	Replace the VSA modulator-control unit .

   NO 

   Repair an open in the F-CAN A H wire and/or the F-CAN A L wire between the gauge control module and the transmitting control unit.