DTC U0029-00: CAN Communication Failure (Bus OFF)

NOTE:

Troubleshoot any PGM-FI DTCs first - Refer to: How to Troubleshoot the Fuel and Emissions Systems How to Troubleshoot the CVT System(CVT System) .
Before you troubleshoot, review the general troubleshooting information .

DTC Description	DTC	Freeze Frame
U0029-00 CAN Communication Failure (Bus OFF)

1. Problem verification:

1. Turn the vehicle to the ON mode.

2. Clear the DTC with the HDS.

3. Turn the vehicle to the OFF (LOCK) mode, then start the engine.

4. Wait 2 seconds or more.

5. Check for DTCs with the HDS.

DTC Description	DTC	Freeze Frame
U0029-00 CAN Communication Failure (Bus OFF)

Is DTC U0029-00 indicated?

YES

The failure is duplicated. Go to step2.

Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting . 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.

2. Open wire check (F-CAN_H, F-CAN_L lines):

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

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

3. Disconnect the following connectors.

VSA modulator-control unit 38P connector

PCM connector A (51P)

4. Check for continuity between test points 1 and 2.

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

Test circuit 2
Test point 1	VSA modulator-control unit 38P connector No. 26
Test point 2	PCM connector A (51P) No. 1

Is there continuity?

YES

The F-CAN_H and F-CAN_L wires are OK. Go to step 3.

Repair an open in the wire between the PCM and the VSA modulator-control unit.

3. VSA modulator-control unit check (update):
1. Reconnect the following connectors.

VSA modulator-control unit 38P connector

PCM connector A (51P)

2. Update the VSA modulator-control unit if it does not have the latest software .

3. Turn the vehicle to the OFF (LOCK) mode, then start the engine.

4. Wait 2 seconds or more.

5. Check for DTCs with the HDS.

Is DTC U0029-00 indicated?

YES

Check for loose terminals and poor connections in the VSA modulator-control unit 38P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit .

NO

Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.