DTC U128F: Gauge Control Module Lost Communication With BSI Radar Unit (Gauge Control Module)

NOTE:  If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Refer to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks (2015-17), or Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks (2018-19) .

DTC (Gauge Control Module)

1. Problem verification

   -1. Clear the DTCs with the HDS.

   - 2. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

   - 3. Wait for at least 6 seconds.

   - 4. Check for DTCs with the HDS.

   DTC Description	DTC
   U128F Gauge Control Module Lost Communication With BSI Radar Unit

   Is DTC U0128F indicated?

   YES 

   Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Check for loose or poor connections.

2. Determine possible failure area (BSI radar unit power and ground, B-CAN line)

   -1. Select B-CAN CONTROL UNITS INFORMATION from the BODY ELECTRICAL SYSTEM SELECT menu, and then select CHECK CONNECTED CONTROL UNITS.

   - 2. Check the DETECT/NOT AVAILABLE information of the BSI RADAR UNIT

   Is DETECT indicated?

   YES 

   Go to step 7. Refer to:  7

   NO 

   Go to step 3.

3. Fuse check

   -1. Check the following fuse.

   Fuse	No. B7 (7.5 A)
   Location	Under-dash fuse/relay box

   Is the fuse OK?

   YES 

   Go to step 4.

   NO 

   Replace the fuse. If the fuse blows again, repair a short to ground in the No. B7 (7.5 A) fuse circuit.

4. Open wire check (IG1 OPTION line)

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

   - 2. Disconnect the following connector.

   Left side BSI radar unit 6P connector

   - 3. Turn the vehicle to the ON mode.

   - 4. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode Left side BSI radar unit 6P connector: disconnected
   Test point 1	Left side BSI radar unit 6P connector No. 1 - Refer to: BSI Radar Unit Connector for Inputs and Outputs (With Auto Idle Stop System), or BSI Radar Unit Connector for Inputs and Outputs (Without Auto Idle Stop System)
   Test point 2	Body ground

   Is there battery voltage?

   YES 

   The IG1 OPTION wire is OK. Go to step 5.

   NO 

   Repair an open or high resistance in the wire.

5. Open wire check (GND line)

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

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

   Test condition	Vehicle OFF (LOCK) mode Left side BSI radar unit 6P connector: disconnected
   Test point 1	Left side BSI radar unit 6P connector No. 6 - Refer to: BSI Radar Unit Connector for Inputs and Outputs (With Auto Idle Stop System), or BSI Radar Unit Connector for Inputs and Outputs (Without Auto Idle Stop System)
   Test point 2	Body ground

   Is there continuity?

   YES 

   The GND wire is OK. Go to step 6.

   NO 

   Repair an open or high resistance in the ground wire or poor ground (G404).

6. Open wire check (B-CAN lines)

   -1. Disconnect the following connector.

   Gauge control module 32P connector

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

   Test condition	Vehicle OFF (LOCK) mode Left side BSI radar unit 6P connector: disconnected Gauge control module 32P connector: disconnected
   Test point 1	Left side BSI radar unit 6P connector No. 3 - Refer to: BSI Radar Unit Connector for Inputs and Outputs (With Auto Idle Stop System), or BSI Radar Unit Connector for Inputs and Outputs (Without Auto Idle Stop System)
   Test point 2	Gauge control module 32P connector No. 25 - Refer to: Gauge Control Module Input Test (2015-17), or Gauge Control Module Input Test (2018-19)

   Is there continuity?

   YES 

   An open or poor connection in the B-CAN_L wire between the left side BSI radar unit and the gauge control module.

   NO 

   An open or poor connection in the B-CAN_H wire between the left side BSI radar unit and the gauge control module.

7. Open wire check (B-CAN lines)

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

   - 2. Disconnect the following connector.

   Left side BSI radar unit 6P connector

   Gauge control module 32P connector

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

   Test condition	Vehicle OFF (LOCK) mode Left side BSI radar unit 6P connector: disconnected Gauge control module 32P connector: disconnected
   Test point 1	Left side BSI radar unit 6P connector No. 3 - Refer to: BSI Radar Unit Connector for Inputs and Outputs (With Auto Idle Stop System), or BSI Radar Unit Connector for Inputs and Outputs (Without Auto Idle Stop System)
   Test point 2	Gauge control module 32P connector No. 25 - Refer to: Gauge Control Module Input Test (2015-17), or Gauge Control Module Input Test (2018-19)

   Is there continuity?

   YES 

   An open or poor connection in the B-CAN_L wire between the left side BSI radar unit and the gauge control module.

   NO 

   An open or poor connection in the B-CAN_H wire between the left side BSI radar unit and the gauge control module.