GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 DTS 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Too Cold in Vehicle - Auxiliary

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Rear air temperature door position

B0433 06

B0433 06

B0428 61

B0428 61

Rear air temp 5-volt reference

B0433 06

B0428 61

B0428 61

B0428 61

Rear air temp low reference

B0428 61

B0428 61

B0428 61

B0428 61

Rear air temperature actuator door control A

B0428 61

B0428 61

B0428 61

B0428 61

Rear air temperature actuator door control B

B0428 61

B0428 61

B0428 61

B0428 61

Rear mode door position

3782 06

3782 06

B3531 61

B3531 61

Rear mode 5-volt reference

3782 06

B3531 61

B3531 61

B3531 61

Rear mode low reference

B3531 61

B3531 61

B3531 61

B3531 61

Rear mode actuator door control A

B3531 61

B3531 61

B3531 61

B3531 61

Rear mode actuator door control B

B3531 61

B3531 61

B3531 61

B3531 61

Circuit/System Description

Battery voltage and ground are supplied to the Aux HVAC control module. The front HVAC control module monitors the position of the rear air temperature actuator and the rear mode actuator. The front HVAC module will move the actuators to the proper position when it receives a request from the Aux HVAC control module on which position to place the actuator. The Aux HVAC control module is powered ON or OFF through GMLAN communication by the vehicle power mode.

Reference Information

Schematic Reference

HVAC Schematics

Connector End View Reference

HVAC Connector End Views

Description and Operation

Air Temperature Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Output Controls
    •  Scan Tool Data Definitions

Circuit/System Testing
  1. Ignition ON, HVAC control module ON and the rear climate control AUX button selected.
  2. Verify the rear aux temp door command changes from 10 to 240 counts when the front HVAC module is adjusted from hot to cold.
    3. ⇒If commanded state does not change replace the front HVAC control module.
  3. Verify the rear aux temp door command changes from 10 to 240 counts when the auxiliary HVAC module is adjusted from hot to cold.
    4. ⇒If commanded state does not change replace the AUX HVAC control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for HVAC or Auxiliary HVAC Control Module replacement, setup and programming.