DTC U0199: Power Seat Control Unit Lost Communication With Door Multiplex Control Unit

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 U0199 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 door multiplex control unit.
From the BODY ELECTRICAL SYSTEM SELECT menu, select B-CAN CONTROL UNITS INFORMATION, and then select CHECK CONNECTED CONTROL UNITS.
Is the power window master switch (door multiplex control unit) detected?

YES -Go to 10 .

NO -Go to next step.
Measure the voltage between body ground and power window master switch 37P connector terminal No. 26.

Fig 1: Checking Continuity Between Power Seat Control Unit Connector B (40P) Terminals And Door Multiplex Control Unit 37P Connector Terminals
Courtesy of ABLE BODY CORP.

Is there less than 0.2V?

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.
Is the fuse OK?

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

NO -Replace the fuse. If the fuse blows again, repair a short to ground on the No. A15 (10A) fuse circuit.
Measure the voltage between body ground and power window master switch 37P connector terminal No. 3 and No. 31 individually.

Fig 2: Checking Continuity Between Power Seat Control Unit Connector B (40P) Terminals And Door Multiplex Control Unit 37P Connector Terminals
Courtesy of ABLE BODY CORP.

Is there less than 0.2V?

YES -Go to next step.

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 power window master switch 37P 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 power window master switch 37P connector terminals No. 28 and No. 30 individually.

Fig 3: Checking Continuity Between Power Seat Control Unit Connector B (40P) Terminals And Door Multiplex Control Unit 37P Connector Terminals
Courtesy of ABLE BODY CORP.

Is there continuity?

YES -Replace the power window master switch (see POWER WINDOW MASTER SWITCH REPLACEMENT ).

NO -Repair an open or poor connection in the wire(s) between the door multiplex control unit and the power seat control unit.