DTC U128D: Power Seat Control Unit Lost Communication With Gauge Control Module (VSP/NE Frame)

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2015 Honda Crosstour, 2014 Honda Crosstour, 2013 Honda Crosstour, 2012 Honda Crosstour, and 2011 Honda Accord Crosstour. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0) and then back to ON (II).
Wait for at least 6 seconds.
Check for DTCs with the HDS.
Is DTC U128D indicated?

YES -Go to next step.

NO -Intermittent failure, the system is OK at this time. Check for loose or poor connections between the power seat control unit and the gauge control module.
From the BODY ELECTRICAL SYSTEM SELECT menu, select B-CAN CONTROL UNITS INFORMATION, and then select CHECK CONNECTED CONTROL UNITS.
Is the gauge control module detected?

YES -Go to 10 .

NO -Go to next step.
Measure the voltage between body ground and gauge control module 32P connector terminals No. 1 and No. 17 individually.

Fig 1: Checking Continuity Between Power Seat Control Unit Connector B 440P) Terminals And Gauge Control Module 32P Connector Terminals
Courtesy of ABLE BODY CORP.

Is there battery voltage?

YES -Go to 9 .

NO -Go to next step.
Turn the ignition switch to LOCK (0).
Check the No. A15 (10A) fuse in the under-hood fuse/relay box and the No. B5 (7.5 A) fuse in the drive's under-dash fuse/relay box.
are the fuses OK?

YES -Repair an open or high resistance in the No. A15 (10A)and/or No. B5 (7.5 A) fuse circuit.

NO -Replace the fuse(s). If the fuse blows again, repair a short to ground on the No. A15 (10A) and/or No. B5 (7.5 A) fuse circuit.
Measure the voltage between body ground and gauge control module 32P connector terminals No. 4 and No. 32 individually.

Fig 2: Checking Continuity Between Power Seat Control Unit Connector B 440P) Terminals And Gauge Control Module 32P Connector Terminals
Courtesy of ABLE BODY CORP.

Is there less than 0.2V?

YES -Go to 11 .

NO -Repair an open or high resistance in the ground wire(s) or poor ground (G401) and/or (G402).
Turn the ignition switch to LOCK (0).
Disconnect the gauge control module 32P connector.
Disconnect power seat control unit connector B (40P).
Check for continuity between power seat control unit connector B (40P) terminals No. 21 and No. 22 and Gauge control module 32P connector terminals No. 30 and No. 31 respectively.

Fig 3: Checking Continuity Between Power Seat Control Unit Connector B 440P) Terminals And Gauge Control Module 32P Connector Terminals
Courtesy of ABLE BODY CORP.

Is there continuity?

YES -Replace the gauge control module (see GAUGE CONTROL MODULE REPLACEMENT ).

NO -Repair an open or poor connection in the B-CAN wire(s) between the gauge control module and the power seat control unit.