Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC U0164: Door Multiplex Control Unit Lost Communication With Climate Control Unit
- Clear the DTCs with the HDS.
- Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode.
- Wait for at least 6 seconds.
- Check for DTCs with the HDS.
Is DTC U0155 indicated?
YES - Go to step 5.
NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections between the door multiplex control unit and the climate control unit.
- From the BODY ELECTRICAL SYSTEM SELECT menu, select B-CAN CONTROL UNITS INFORMATION, and then select CHECK CONNECTED CONTROL UNITS.
Is the climate control unit detected?
YES - Go to step 9.
NO - Go to step 6.
- Measure the voltage between body ground and climate control unit connector A (32P) terminal No. 15.Fig 1: Measuring Voltage Between Body Ground And Climate Control Unit Connector A (32P) Terminal No. 15
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Go to step 8.
NO - Go to step 7.
- Check the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box.
Is the fuse OK?
YES - Repair an open or high resistance in the No. 16 (7.5 A) fuse circuit.
NO - Replace the fuse. If the fuse blows again, repair a short to ground in the No. 16(7.5 A) fuse circuit.
- Measure the voltage between body ground and climate control unit connector A (32P) terminal No. 1.Fig 2: Measuring Voltage Between Body Ground And Climate Control Unit Connector A (32P) Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there less than 0.2 V?
YES - Go to step 9.
NO - Repair an open or high resistance in the ground wire or poor ground (G403).
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Disconnect climate control unit connector A (32P).
- Disconnect the power window master switch 37P connector.
- Check for continuity between climate control unit connector A (32P) terminals No. 7 and No. 8 and power window master switch 37P connector terminals No. 33 and No. 35 respectively.Fig 3: Checking Continuity Between Climate Control Unit Connector A (32P) And Power Window Master Switch 37P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Replace the climate control unit (see EVAPORATOR TEMPERATURE SENSOR REPLACEMENT ).
NO - Repair an open or poor connection in the B-CAN wire between the door multiplex control unit and the climate control unit.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.