DTC Troubleshooting: U0100, U0122
DTC U0100: Power Control Unit (Body Control Module) Lost Communication with PCM
DTC U0122: Power Control Unit (Body Control Module) Lost Communication with VSA Modulator-Control Unit (VSA Message)
NOTE:
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 Description
DTC
U0100 Power Control Unit (Body Control Module) Lost Communication with PCM
  
U0122 Power Control Unit (Body Control Module) Lost Communication with VSA Modulator-Control Unit (VSA Message)
  

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTCs with the HDS.


?3.
Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

?4.
Wait for at least 6 seconds.

?5.
Check for DTCs with the HDS.
DTC Description
DTC
U0100 Power Control Unit (Body Control Module) Lost Communication with PCM
  
U0122 Power Control Unit (Body Control Module) Lost Communication with VSA Modulator-Control Unit (VSA Message)
  

Are any DTCs indicated?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the transmitting control units and the gauge control module.?
2.
Open wire check (F-CAN_H line, F-CAN_L line):

Open wire check (F-CAN_H line, F-CAN_L line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Body control module connector B (36P)

?3.
U0100: Jump the SCS line with the HDS, and wait more than 1 minute.


?4.
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 table).

DTC
Connector
U0100
PCM connector A (50P)*1/*3
PCM connector No.2 (58P)*2
U0122
VSA modulator-control unit 46P connector
*1: L15B7/L15BA/L15BY engine
*2: K20C1 engine
*3: K20C2 engine

?5.
Check for continuity between the receiving control unit and the transmitting control unit on the F-CAN_H circuit and the F-CAN_L circuit.
Test condition
Receiving control unit connector(s): disconnected
Transmitting control unit connector(s) for indicated DTCs: disconnected

DTC
Circuit name
Receiving control unit
Transmitting control unit
Connector
Terminal
Connector
Terminal
U0100*1/*3
F-CAN_H
Body control module connector B (36P)
No. 22
PCM connector A (50P)
No. 37
F-CAN_L
No. 23
No. 36
U0100*2
F-CAN_H
Body control module connector B (36P)
No. 22
PCM connector No.2 (58P)
No. 15
F-CAN_L
No. 23
No. 27
U0122
F-CAN_H
Body control module connector B (36P)
No. 22
VSA modulator-control unit 46P connector
No. 20
F-CAN_L
No. 23
No. 21
*1: L15B7/L15BA/L15BY engine
*2: K20C1 engine
*3: K20C2 engine

Is there continuity?

     
YES
     
     
     
The F-CAN_H wire and the F-CAN_L wire are OK.
Refer to the DTC shown on the display, substitute or replace the control unit based on the instructions (see table).?
DTC
Operation for transmitting control unit
U0100
Substitute a known-good PCM, then recheck. If DTC U0100 goes away and the PCM was substituted, replace the original PCM.?
U0122
Replace the VSA modulator-control unit.?
     
NO
     
     
     
Repair an open in the F-CAN_H wire and/or the F-CAN_L wire between the receiving control unit and the transmitting control unit.?