DTC U0127: Gauge Control Module Lost Communication With Keyless Access/TPMS Control Unit (V6, Gauge Control Module without CAN gateway)

DTC (Gauge Control Module)

NOTE:  Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems (L4), or How to Troubleshoot the Dual Clutch Transmission (DCT), or How to Troubleshoot the Brake Booster Pressure Monitoring System (With Auto Idle Stop System), or How to Troubleshoot the Fuel and Emissions Systems (V6, Without Auto Idle Stop System), or How to Troubleshoot the Fuel and Emissions Systems (V6, With Auto Idle Stop System) .

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
   U0127 Gauge Control Module Lost Communication With Keyless Access/TPMS Control Unit

   Is DTC U0127 indicated?

   YES 

   Go to step 2.

   NO 

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

2. Fuse check

   -1. Check the following fuse.

   Fuse	No. B10 (7.5 A)
   Location	Under-dash fuse/relay box

   Is the fuse OK?

   YES 

   Go to step 3.

   NO 

   Replace the fuse. If the fuse blows again, repair a short to ground in the No. B10 (7.5 A) fuse circuit.

3. Open wire check (IG1 VSA/ABS line)

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

   - 2. Disconnect the following connectors.

   Keyless access/TPMS control unit connector A (32P)

   Keyless access/TPMS control unit connector B (36P)

   Keyless access/TPMS control unit connector C (20P)

   - 3. Turn the vehicle to the ON mode.

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

   Test condition	Vehicle ON mode Keyless access/TPMS control unit connector A (32P): disconnected Keyless access/TPMS control unit connector B (36P): disconnected Keyless access/TPMS control unit connector C (20P): disconnected
   Test point 1	Keyless access/TPMS control unit connector B (36P) No. 34
   Test point 2	Body ground

   Is there battery voltage?

   YES 

   The IG1 VSA/ABS wire is OK. Go to step 4.

   NO 

   Repair an open or high resistance in the wire.

4. Open wire check (GND lines)

   -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 Keyless access/TPMS control unit connector A (32P): disconnected Keyless access/TPMS control unit connector B (36P): disconnected Keyless access/TPMS control unit connector C (20P): disconnected
   Test point 1	Keyless access/TPMS control unit connector A (32P) No. 17
   Test point 2	Body ground

   Test point 1	Keyless access/TPMS control unit connector B (36P) No. 36
   Test point 2	Body ground

   Is there continuity?

   YES 

   The GND wires are OK. Go to step 5.

   NO 

   Repair an open or high resistance in the ground wire or poor ground (G302).

5. Open wire check (F-CAN A lines)

   -1. Connect terminals A and B with a jumper wire.

   Terminal A	Keyless access/TPMS control unit connector C (20P) No. 2
   Terminal B	Keyless access/TPMS control unit connector C (20P) No. 12

   - 2. Disconnect the following connector.

   Gauge control module 32P connector

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

   Test condition	Vehicle OFF (LOCK) mode Keyless access/TPMS control unit connector A (32P): disconnected Keyless access/TPMS control unit connector B (36P): disconnected Keyless access/TPMS control unit connector C (20P): disconnected Gauge control module 32P connector: disconnected
   Test point 1	Gauge control module 32P connector No. 27 - Refer to: Gauge Control Module Input Test (2015-17), or Gauge Control Module Input Test (2018-19)
   Test point 2	Gauge control module 32P connector No. 28 - Refer to: Gauge Control Module Input Test (2015-17), or Gauge Control Module Input Test (2018-19)

   Is there continuity?

   YES 

   The F-CAN A wires are OK. Replace the gauge control module .

   NO 

   An open or poor connection in the F-CAN A wires between the keyless access/TPMS control unit and the gauge control module.