U0164-Lost Communication With HVAC Control Module: Notes

Fig 1: U0164-Lost Communication With HVAC Control Module Diagram

Courtesy of DAIMLERCHRYSLER CORP.

For a complete wiring diagram Refer to  SYSTEM WIRING DIAGRAMS  . 

• When Monitored: 
  • With the ignition on
  • Battery voltage between 10 and 16 volts
  • IOD fuse installed
  • FCM is configured correctly
• Set Condition: 

  Bus messages not received from the A/C Heater Control (HVAC) for approximately 2 to 5 seconds.

Possible Causes 

1. CAN B BUS CIRCUITS OPEN OR SHORTED
2. DTCS RELATED TO BATTERY VOLTAGE, IGNITION/OR VIN MESSAGES
3. FCM NOT CONFIGURED CORRECTLY
4. A/C HEATER CONTROL
5. A/C HEATER CONTROLS POWER AND GROUND
6. MODULE THAT SET THIS DTC