DTC Troubleshooting: U0122 (V6, PGM-FI System: With ACC)

DTC Troubleshooting: U0122

DTC U0122: F-CAN Malfunction (PCM-VSA Modulator-Control Unit)

NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
U0122 F-CAN Malfunction (PCM-VSA Modulator-Control Unit)

DTC check:

DTC check

?1.	Press the engine start/stop button to select the ON mode.

?2.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
U0029 F-CAN Malfunction (BUS-OFF (PCM))
U0122 F-CAN Malfunction (PCM-VSA Modulator-Control Unit)

Are DTC U0029 and U0122 indicated at the same time?


	YES

Do the troubleshooting for DTC U0029.?


	NO

Go to step 2.

Problem verification:

Problem verification

?1.	Clear the DTC with the HDS.

?2.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
U0122 F-CAN Malfunction (PCM-VSA Modulator-Control Unit)

Is DTC U0122 indicated?


	YES

The failure is duplicated. Go to step 3.


	NO

Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the VSA modulator-control unit and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?

VSA system check:

VSA system check

?1.	Check for communication to the VSA system with the HDS.

Does the HDS communicate with the VSA modulator-control unit?


	YES

Go to step 4.


	NO

Go to the symptom troubleshooting for ABS indicator, brake system indicator, and VSA indicator do not go off.?

Open wire check (F-CAN_H line):

Open wire check (F-CAN_H line)

?1.	Press the engine start/stop button to select the OFF mode.

?2.	Jump the SCS line with the HDS.

?3.

Disconnect the following connectors.

PCM connector A (51P)

VSA modulator-control unit 38P connector

?4.

Check for continuity between test points 1 and 2.

Test condition	OFF mode
	PCM connector A (51P): disconnected
	VSA modulator-control unit 38P connector: disconnected
Test circuit	F-CAN_H
Test point 1	VSA modulator-control unit 38P connector No. 38 (WHT)
Test point 2	PCM connector A (51P) No. 9 (WHT)

Is there continuity?


	YES

Go to step 5.


	NO

Repair an open in the F-CAN_H wire between the PCM (A9) and the VSA modulator-control unit.?

Open wire check (F-CAN_L line):

Open wire check (F-CAN_L line)

?1.

Check for continuity between test points 1 and 2.

Test condition	OFF mode
	PCM connector A (51P): disconnected
	VSA modulator-control unit 38P connector: disconnected
Test circuit	F-CAN_L
Test point 1	VSA modulator-control unit 38P connector No. 26 (RED)
Test point 2	PCM connector A (51P) No. 10 (RED)

Is there continuity?


	YES

Replace the original VSA modulator-control unit.?


	NO

Repair an open in the F-CAN_L wire between the PCM (A10) and the VSA modulator-control unit.?