DTC Troubleshooting: U0038(CVT (TCM))

DTC U0038  : TM-CAN Malfunction (TCM-PCM)

NOTE: 

• Before you troubleshoot, review the General Troubleshooting Information .
• This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

DTC(CVT)

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.

   -4. Turn the vehicle to the ON mode.

   -5. Check for Pending or Confirmed DTCs in the PGM-FI system with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
   U0038 TM-CAN Malfunction (TCM-PCM)

   Is DTC U0038 indicated?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Check for poor connections and loose terminals between the PCM 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.

2. Open wire check (TM-CAN_H line and TM-CAN_L line)

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

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

   NOTE:  This step must be done to protect the TCM and the PCM from damage.

   -3. Disconnect the following connectors.

   TCM 50P connector

   PCM connector A (50P)

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

   TM-CAN_H line 

   Test condition	Vehicle OFF (LOCK) mode
   	TCM 50P connector: disconnected
   	PCM connector A (50P): disconnected
   Test point 1	TCM 50P connector No. 4
   Test point 2	PCM connector A (50P) No. 21

   TM-CAN_L line 

   Test condition	Vehicle OFF (LOCK) mode
   	TCM 50P connector: disconnected
   	PCM connector A (50P): disconnected
   Test point 1	TCM 50P connector No. 12
   Test point 2	PCM connector A (50P) No. 20

   Are there continuity?

   YES 

   The TM-CAN_H wire and/or TM-CAN_L wire are not open. Go to step 3.

   NO 

   Repair an open in the TM-CAN_H wire and/or TM-CAN_L wire between the PCM and the TCM.

3. Shorted wire check (TM-CAN_H line and TM-CAN_L line)

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

   TM-CAN_H line 

   Test condition	Vehicle OFF (LOCK) mode
   	TCM 50P connector: disconnected
   	PCM connector A (50P): disconnected
   Test point 1	TCM 50P connector No. 4
   Test point 2	Body ground

   TM-CAN_L line 

   Test condition	Vehicle OFF (LOCK) mode
   	TCM 50P connector: disconnected
   	PCM connector A (50P): disconnected
   Test point 1	TCM 50P connector No. 12

   Test point 2

   Body ground

   Are there continuity?

   YES 

   Repair a short to ground in the TM-CAN_H wire and/or TM-CAN_L wire between the PCM and the TCM.

   NO 

   The TM-CAN_H wire and/or TM-CAN_L wire are OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or replace the original PCM .