DTC U1281, U128D, U1299 (Multiplex Control Unit, Door)

DTC U1281  : Power Window Master Switch Lost Communication with MICU (Body Control Module)DTC U128D  : Power Window Master Switch Lost Communication with Gauge Control Module DTC U1299  : Power Window Master Switch Lost Communication with Climate Control Unit

NOTE: 

• If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .
• According to the detected DTC (s), check for the power circuit and the ground circuit of the control unit which cannot communicate with the power window master switch.
• Refer to the DTC shown on the display, then inspect the connectors and terminals based on the instructions.

DTC (Door Multiplex Control Unit)

1. Problem verification

   -1. Clear the DTC 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
   U1281 Power window master switch lost communication with MICU (body control module)
   U128D Power window master switch lost communication with gauge control module
   U1299 Power window master switch lost communication with climate control unit

   Are any DTCs indicated?

   YES 

   Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the transmitting control units and the power window master switch.

2. Open wire check (B-CAN_H line, B-CAN_L line)

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

   -2. Disconnect the receiving control unit connector.

   Power window master switch 37P connector

   -3. According to the detected DTC on the following table, disconnect the transmitting control unit connector (s).

   DTC	Connector
   U1281	Body control module connector A (66P)
   U128D	Gauge control module connector A (32P)
   U1299	Climate control unit connector A (32P)

   -4. Check for continuity between the receiving control unit and the transmitting control unit on the B-CAN_H circuit and the B-CAN_L circuit.

   Test condition

   Vehicle OFF (LOCK) mode Power window master switch 37P connector: disconnected Transmitting control unit connector (s) for indicated DTCs: disconnected

   DTC	Circuit name	Receiving control unit		Transmitting control unit
   		Connector	Terminal	Connector	Terminal
   U1281	B-CAN_H	Power window master switch 37P connector	No. 32	Body control module connector A (66P)	No. 54
   	B-CAN_L		No. 31		No. 55
   U128D	B-CAN_H	Power window master switch 37P connector	No. 32	Gauge control module connector A (32P)	No. 22
   	B-CAN_L		No. 31		No. 23
   U1299	B-CAN_H	Power window master switch 37P connector	No. 32	Climate control unit connector A (32P)	No. 25
   	B-CAN_L		No. 31		No. 8

   Is there continuity?

   YES 

   The B-CAN_H wire and the B-CAN_L wire are OK.

   Refer to the DTC shown on the display, then substitute or replace the control unit based on the instructions (see table).

   DTC	Operation for transmitting control unit
   U1281	Substitute a known-good body control module , then recheck. If DTC U1281 goes away after substitution, replace the original body control module .
   U128D	Substitute a known-good gauge control module , then recheck. If DTC U128D goes away after substitution, replace the original gauge control module .

   DTC	Operation for transmitting control unit
   U1299	Substitute a known-good climate control unit , then recheck. If DTC U1299 goes away after substitution, replace the original climate control unit .

   NO 

   Repair an open in the B-CAN_H wire and/or the B-CAN_L wire between the power window master switch and the transmitting control unit.