DTC U0164: Door Multiplex Control Unit Lost Communication With Climate Control Unit

DTC (Door Multiplex Control Unit)

• 1. Problem verification:

  1. Clear the DTCs 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
  U0164 Door Multiplex Control Unit Lost Communication With Climate Control Unit

  Is DTC U0164 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 (climate control unit 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 CLIMATE CONTROL UNIT

  Is DETECT indicated?

  YES 

  Go to step 7.

  NO 

  Go to step 3.

• 3. Fuse check:

  1. Check the following fuse.

  Fuse	No. B22 (7.5 A)
  Location	Under-dash fuse/relay box

  Is the fuse OK?

  YES 

  Go to step 4.

  NO 

  Replace the fuse. If the fuse blows again, repair a short to ground in the No. B22 (7.5 A) fuse circuit.

• 4. Open wire check (IG2 A/C line):

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

  2. Disconnect the following connector.

  Climate control unit 32P connector

  3. Turn the vehicle to the ON mode.

  4. Measure the voltage between test points 1 and 2.

  Test condition	Vehicle ON mode Climate control unit 32P connector: disconnected
  Test point 1	Climate control unit 32P connector No. 12
  Test point 2	Body ground

  Is there battery voltage?

  YES 

  The IG2 A/C wire is OK. Go to step 5.

  NO 

  Repair an open or high resistance in the wire.

• 5. Open wire check (GND line):

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

  2. Disconnect the following connector.

  Climate control unit 32P connector

  3. Check for continuity between test points 1 and 2 individually.

  Test condition	Vehicle OFF (LOCK) mode Climate control unit 32P connector: disconnected
  Test point 1	Climate control unit 32P connector No. 1
  Test point 2	Body ground

  Test point 1	Climate control unit 32P connector No. 25
  Test point 2	Body ground

  Is there continuity?

  YES 

  The GND wires are OK. Go to step 6.

  NO 

  Repair an open or high resistance in the ground wire or poor ground (G502).

• 6. Open wire check (B-CAN lines):

  1. Disconnect the following connector.

  Power window master switch 37P connector

  2. Check for continuity between test points 1 and 2.

  Test condition	Vehicle OFF (LOCK) mode Climate control unit 32P connector: disconnected Power window master switch 37P connector: disconnected
  Test point 1	Power window master switch 37P connector No. 28 - Refer to: Power Window Master Switch Input Test(Without Door Multiplex Control Unit)Power Window Master Switch Input Test(With Door Multiplex Control Unit)
  Test point 2	Climate control unit 32P connector No. 16

  Is there continuity?

  YES 

  An open or poor connection in the B-CAN_L wire between the power window master switch and the climate control unit.

  NO 

  An open or poor connection in the B-CAN_H wire between the power window master switch and the climate control unit.

• 7. Open wire check (B-CAN lines):

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

  2. Disconnect the following connectors.

  Power window master switch 37P connector Climate control unit 32P connector

  3. Check for continuity between test points 1 and 2.

  Test condition	Vehicle OFF (LOCK) mode Power window master switch 37P connector: disconnected Climate control unit 32P connector: disconnected
  Test point 1	Power window master switch 37P connector No. 28 - Refer to: Power Window Master Switch Input Test(Without Door Multiplex Control Unit)Power Window Master Switch Input Test(With Door Multiplex Control Unit)

  Test point 2

  Climate control unit 32P connector No. 16

  Is there continuity?

  YES 

  An open or poor connection in the B-CAN_L wire between the power window master switch and the climate control unit.

  NO 

  An open or poor connection in the B-CAN_H wire between the power window master switch and the climate control unit.