DTC U0146 (A/T)

DTC U0146  : F-CAN Malfunction (TCM - CAN Gateway)

NOTE:  Before you troubleshoot, review the General Troubleshooting Information .

DTC (A/T)

1. CAN gateway system DTC check

   -1. Check for CAN gateway system DTCs with the HDS.

   DTC Description	DTC

   Are any DTCs indicated?

   YES 

   Go to the indicated DTC's troubleshooting for CAN gateway system .

   NO 

   Go to step 2.

2. F-CAN circuit communication check

   -1. Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.

   F-CAN Bus Connected Unit Check

   Does the TCM detect the CAN gateway Bus channels A and D?

   Bus A is Not Available

   Go to step 3.

   Bus D is Not Available

   Go to step 4.

   Bus A and D are Available

   Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the CAN gateway and the TCM. 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.

3. 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 following connectors.

   CAN gateway 16P connector

   TCM connector A (23P)

   -3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	CAN gateway 16P connector: disconnected
   	TCM connector A (23P): disconnected
   Test point 1	CAN gateway 16P connector (female terminals) No. 3:
   Test point 2	TCM connector A (23P) No. 19

   Test point 1	CAN gateway 16P connector (female terminals) No. 11:
   Test point 2	TCM connector A (23P) No. 18

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The F-CAN A_H wire and the F-CAN A_L wire are OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good TCM , then recheck. If this DTC goes away and the TCM was substituted, replace the original TCM .

   NO 

   Repair an open in the F-CAN A_H wire and/or the F-CAN A_L wire between the CAN gateway and the TCM.

4. Open wire check (F-CAN D_H line, F-CAN D_L line)

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

   -2. Disconnect the following connectors.

   CAN gateway 16P connector

   TCM connector A (23P)

   -3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	CAN gateway 16P connector: disconnected
   	TCM connector A (23P): disconnected
   Test point 1	CAN gateway 16P connector (female terminals) No. 7:
   Test point 2	TCM connector A (23P) No. 13

   Test point 1	CAN gateway 16P connector (female terminals) No. 15:
   Test point 2	TCM connector A (23P) No. 12

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The F-CAN D_H wire and the F-CAN D_L wire are OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good TCM , then recheck. If this DTC goes away and the TCM was substituted, replace the original TCM .

   NO 

   Repair an open in the F-CAN D_H wire and/or the F-CAN D_L wire between the CAN gateway and the TCM.