DTC Troubleshooting: U128D
DTC U128D: Lost Communication With METER
DTC Description
DTC
U128D Lost communication with METER
  

1.
Problem verification:

Problem verification
?1.
Clear the DTCs with the HDS.


?2.
Turn the ignition switch to LOCK (0) and then back to ON (II).

?3.
Wait for at least 6 seconds.

?4.
Check for DTCs with the HDS.
DTC Description
DTC
U128D Lost communication with METER
  

Is DTC U128D 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 (gauge control module power and ground, B CAN line):

Determine possible failure area (gauge control module 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:

Fuse check
?1.
Check the following fuses.
Fuse
No. A21 (10 A)
Location
Under-hood fuse/relay box

Fuse
No. B5 (7.5 A)
Location
Under-dash fuse/relay box

Is each fuse OK?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Replace the fuse. If the fuse blows again, repair a short to ground in the No. A21 (10 A) and/or No. B5 (7.5 A) fuse circuit(s).?
4.
Open wire check (+B BACK UP line):

Open wire check (+B BACK UP line)
?1.
Turn the ignition switch to LOCK (0).

?2.
Disconnect the following connector.

?3.
Measure the voltage between test points 1 and 2.
Test condition
IG LOCK (0)
Gauge control module connector A (32P): disconnected
Test circuit
+B BACK UP
Test point 1
Gauge control module connector A (32P) 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 resistance in the wire.?
5.
Open wire check (IG1 METER line):

Open wire check (IG1 METER line)
?1.
Turn the ignition switch to ON (II).

?2.
Measure the voltage between test points 1 and 2.
Test condition
IG ON (II)
Gauge control module connector A (32P): disconnected
Test circuit
IG1 METER
Test point 1
Gauge control module connector A (32P) 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 resistance in the wire.?
6.
Open wire check (GND lines):

Open wire check (GND lines)
?1.
Turn the ignition switch to LOCK (0).

?2.
Check for continuity between test points 1 and 2 individually.
Test condition
IG LOCK (0)
Gauge control module connector A (32P): disconnected
Test circuit
GND
Test point 1
Gauge control module connector A (32P) No. 4 (BRN)
Test point 2
Body ground

Test circuit
GND
Test point 1
Gauge control module connector A (32P) 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 resistance in the ground wire or poor ground (G502).?
7.
Open wire check (B CAN lines):

Open wire check (B CAN lines)
?1.
Disconnect the following connector.

?2.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0)
Gauge control module connector A (32P): disconnected
Immobilizer-keyless control unit 7P connector: disconnected
Test circuit
B CAN-H
Test point 1
Immobilizer-keyless control unit 7P connector No. 4 (PNK)
Test point 2
Gauge control module connector A (32P) No. 30 (PNK)


Is there continuity?

     
YES
     
     
     
An open or poor connection in the B CAN-L wire between the immobilizer-keyless control unit and the gauge control module.?
     
NO
     
     
     
An open or poor connection in the B CAN-H wire between the immobilizer-keyless control unit and the gauge control module.?
8.
Open wire check (B CAN lines):

Open wire check (B CAN lines)
?1.
Turn the ignition switch to LOCK (0).

?2.
Disconnect the following connectors.

?3.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0)
Immobilizer-keyless control unit 7P connector: disconnected
Gauge control module connector A (32P): disconnected
Test circuit
B CAN-H
Test point 1
Immobilizer-keyless control unit 7P connector No. 4 (PNK)
Test point 2
Gauge control module connector A (32P) No. 30 (PNK)


Is there continuity?

     
YES
     
     
     
An open or poor connection in the B CAN-L wire between the immobilizer-keyless control unit and the gauge control module.?
     
NO
     
     
     
An open or poor connection in the B CAN-H wire between the immobilizer-keyless control unit and the gauge control module.?