DTC Troubleshooting: U0056-00 (K20C2: With CAN gateway)

1.

Problem verification:

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.

?4.	Turn the vehicle to the ON mode, and wait 6 seconds.

?5.

Check for DTCs with the HDS.

DTC Description	DTC
U0056-00 CAN Gateway F-CAN ch C Bus Off

Is DTC U0056-00 indicated?


	YES

The failure is duplicated. Go to step 2.


	NO

Intermittent failure, the system is OK at this time. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?

2.

Shorted unit check (gauge control module):

Shorted unit check (gauge control module)

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

?2.

Disconnect the following connector.

Gauge control module connector A (32P)

?3.	Turn the vehicle to the ON mode.

?4.	Clear the DTC with the HDS.

?5.	Turn the vehicle to the OFF (LOCK) mode.

?6.	Turn the vehicle to the ON mode, and wait 6 seconds.

?7.

Check for DTCs with the HDS.

DTC Description	DTC
U0056-00 CAN Gateway F-CAN ch C Bus Off

Is DTC U0056-00 indicated?


	YES (without display audio)

Go to step 4.


	YES (with display audio)

Go to step 3.


	NO

Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good gauge control module, then recheck. If DTC U0056-00 goes away and the gauge control module was substituted, replace the original gauge control module.?

3.

Shorted unit check (audio unit):

Shorted unit check (audio unit)

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

?2.

Disconnect the following connector.

Audio unit connector E (16P)

?3.	Turn the vehicle to the ON mode.

?4.	Clear the DTC with the HDS.

?5.	Turn the vehicle to the OFF (LOCK) mode.

?6.	Turn the vehicle to the ON mode, and wait 6 seconds.

?7.

Check for DTCs with the HDS.

DTC Description	DTC
U0056-00 CAN Gateway F-CAN ch C Bus Off

Is DTC U0056-00 indicated?


	YES

Go to step 4.


	NO

Substitute a known-good audio unit, then recheck. If DTC U0056-00 goes away and the audio unit was substituted, replace the original audio unit.?

4.

Shorted wire check (F-CAN C_H line):

Shorted wire check (F-CAN C_H line)

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

?2.

Disconnect the following connector.

CAN gateway 16P connector

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Gauge control module connector A (32P): disconnected
	Audio unit connector E (16P) (with display audio): disconnected
	CAN gateway 16P connector: disconnected
Test point 1	CAN gateway 16P connector (female terminals) No. 5:
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the F-CAN C_H wire between the CAN gateway and the connected units.?


	NO

The F-CAN C_H wire is not shorted to ground. Go to step 5.

5.

Shorted wire check (F-CAN C_L line):

Shorted wire check (F-CAN C_L line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Gauge control module connector A (32P): disconnected
	Audio unit connector E (16P) (with display audio): disconnected
	CAN gateway 16P connector: disconnected
Test point 1	CAN gateway 16P connector (female terminals) No. 13:
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the F-CAN C_L wire between the CAN gateway and the connected units.?


	NO

The F-CAN C_L wire is not shorted to ground. Go to step 6.

6.

Shorted wire check (F-CAN C_H line to F-CAN C_L line):

Shorted wire check (F-CAN C_H line to F-CAN C_L line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Gauge control module connector A (32P): disconnected
	Audio unit connector E (16P) (with display audio): disconnected
	CAN gateway 16P connector: disconnected
Test point 1	CAN gateway 16P connector (female terminals) No. 5:
Test point 2	CAN gateway 16P connector (female terminals) No. 13:

Is there continuity?


	YES

Repair a short in the F-CAN C_H wire to the F-CAN C_L wire between CAN gateway terminals No. 5 and No. 13.?


	NO

Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good CAN gateway, then recheck. If DTC U0056-00 goes away and the CAN gateway was substituted, replace the original CAN gateway.?