DTC U128D: Keyless Access Control Unit Lost Communication With Gauge Control Module
- 1. Problem verification:
- 1. Clear the DTCs with the HDS.
- 2. Press the engine start/stop button to select the OFF mode and then the ON mode.
- 3. Wait for at least 6 seconds.
- 4. Check for DTCs with the HDS.
Is DTC U128D indicated?
YES
Go to step2.
NO
Intermittent failure, the system is OK at this time. Check for loose or poor connections.
- 2. Determine possible failure area (gauge control module (tach) 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 GAUGE CONTROL MODULE.
Is DETECT indicated?
YES
Go to step 8.
NO
Go to step 3.
- 3. Fuse check:
- 1. Check the following fuse.
Fuse No. A29 (10 A) Location Under-hood fuse/relay box Is the fuse OK?
YES
Go to step4.
NO
Replace the fuse. If the fuse blows again, repair a short to ground in the No. A29 (10 A) fuse circuit.
- 4. Open wire check (+B_BACK_UP line):
- 1. Press the engine start/stop button to select the OFF mode.
- 2. Disconnect the following connector.
Gauge control module (tach) 32P connector - 3. Measure the voltage between test points 1 and 2.
Test condition OFF mode Gauge control module (tach) 32P connector: disconnected Test circuit +B_BACK_UP Test point 1 Gauge control module (tach) 32P connector No. 1 (WHT) Test point 2 Body ground Is there battery voltage?
YES
The +B_BACK_UP wire is OK. Go to step 5.
NO
Repair an open or high Ω in the wire.
- 5. Open wire check (IG1_METER line):
- 1. Press the engine start/stop button to select the ON mode.
- 2. Measure the voltage between test points 1 and 2.
Test condition ON mode Gauge control module (tach) 32P connector: disconnected Test circuit IG1_METER Test point 1 Gauge control module (tach) 32P connector No. 17 (BRN) Test point 2 Body ground Is there battery voltage?
YES
The IG1_METER wire is OK. Go to step 6.
NO
Repair an open or high Ω in the wire.
- 6. Open wire check (GND lines):
- 1. Press the engine start/stop button to select the OFF mode.
- 2. Check for continuity between test points 1 and 2 individually.
Test condition OFF mode Gauge control module (tach) 32P connector: disconnected Test circuit GND Test point 1 Gauge control module (tach) 32P connector No. 4 (BLK) Test point 2 Body ground Test circuit GND Test point 1 Gauge control module (tach) 32P connector No. 32 (BRN) Test point 2 Body ground Is there continuity?
YES
The GND wires are OK. Go to step 7.
NO
Repair an open or high Ω in the ground wire or poor ground (G502/G503).
- 7. Open wire check (B_CAN lines):
- 1. Disconnect the following connector.
Keyless access control unit connector B (28P) - 2. Check for continuity between test points 1 and 2.
Test condition OFF mode Gauge control module (tach) 32P connector: disconnected Keyless access control unit connector B (28P): disconnected Test circuit B_CAN-H Test point 1 Keyless access control unit connector B (28P) No. 6 (PNK) Test point 2 Gauge control module (tach) 32P connector No. 30 (PNK) Is there continuity?
YES
An open or poor connection in the B_CAN-L wire between the MICU and the gauge control module (tach).
NO
An open or poor connection in the B_CAN-H wire between the MICU and the gauge control module (tach).
- 8. Open wire check (B_CAN lines):
- 1. Press the engine start/stop button to select the OFF mode.
- 2. Disconnect the following connectors.
Gauge control module (tach) 32P connector Keyless access control unit connector B (28P) - 3. Check for continuity between test points 1 and 2.
Test condition OFF mode Gauge control module (tach) 32P connector: disconnected Keyless access control unit connector B (28P): disconnected Test circuit B_CAN-H Test point 1 Keyless access control unit connector B (28P) No. 6 (PNK) Test point 2 Gauge control module (tach) 32P connector No. 30 (PNK) Is there continuity?
YES
An open or poor connection in the B_CAN-L wire between the MICU and the gauge control module (tach).
NO
An open or poor connection in the B_CAN-H wire between the MICU and the gauge control module (tach).