B106E-14

B106E-14-REAR BLOWER CONTROL - CIRCUIT SHORT TO GROUND OR OPEN





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Rear A/C Heater Control works in conjunction with the A/C Heater Control to control the rear blower motor, rear temperature control and rear mode control. The Rear A/C Heater Control is constantly monitored by the A/C Heater Control for proper operation. If the monitored signal circuits are out of a calibrated range a DTC will set. For further information Description and Operation.

- When Monitored:
With the ignition on.

- Set Condition:
If the A/C Heater Control detects a short to ground or an open on the Rear Blower Motor Control circuit. If a valid voltage is detected the DTC will change from active to stored and stay in the controllers memory for 100 consecutive ignition cycles.





Always perform the HVAC Pre-Diagnostic Troubleshooting procedure before proceeding. HVAC Pre-Diagnostic Troubleshooting Procedure.

1. VERIFY THE DTC IS ACTIVE
1. Ignition on, engine not running.
2. With the scan tool, erase HVAC DTCs.
3. Turn the ignition off, wait 10 seconds, and turn the ignition on.
4. After waiting a minimum of 30 seconds, read HVAC DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- Go To 8

2. CHECK FOR TOTALLY INTEGRATED POWER MODULE DTCS
1. Ignition on, engine not running.
2. With the scan tool, read Totally Integrated Power Module (TIPM) DTCs.

Does the scan tool display any Totally Integrated Power Module (TIPM) DTCs as active?

Yes

- Testing and Inspection and perform the appropriate diagnostic procedure.

No

- Go To 3

3. CHECK THE (C57) REAR BLOWER MOTOR CONTROL CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off to the lock position.
2. Disconnect the A/C Heater Control C2 harness connector.
3. Disconnect the Rear Blower Motor Power Module C1 harness connector.
4. Measure the resistance between ground and the (C57) Rear Blower Motor Control circuit.

Is the resistance below 100k Ohms?

Yes

- Repair the (C57) Rear Blower Motor Control circuit for a short to ground.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Go To 4

4. CHECK THE (C57) REAR BLOWER MOTOR CONTROL CIRCUIT FOR AN OPEN




1. Measure the resistance of the (C57) Rear Blower Motor Control circuit between A/C Heater Control C2 harness connector and the Rear Blower Motor Power Module harness connector.

Is the resistance below 1.0 Ohm?

Yes

- Go To 5

No

- Repair the (C57) Rear Blower Motor Control circuit for an open or high resistance.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

5. CHECK THE (C51) FUSED REAR BLOWER MOTOR RELAY OUTPUT CIRCUIT FOR AN OPEN




1. Ignition on, engine not running.
2. Using a 12-volt test light connected to ground, check the (C51) Fused Rear Blower Motor Relay Output Circuit in the Rear Blower Motor Power Module harness connector.

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Repair the (C51) Fused Rear Blower Motor Relay Output circuit for an open or high resistance.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Go To 6

6. CHECK THE (Z923) GROUND CIRCUIT FOR AN OPEN




1. Using a 12-volt test light connected to 12-volts, check the (Z923) Ground circuit.

Does the test light illuminate brightly?

Yes

- Go To 7

No

- Repair the (C923) Ground circuit for an open or high resistance.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

7. CHECK THE REAR BLOWER MOTOR POWER MODULE
1. Turn the ignition off to the lock position.
2. Replace the Rear Blower Motor Power Module. Rear Blower Motor Power Module - Removal.
3. Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

Did this DTC reset performing the HVAC Verification Test?

Yes

- Replace and program the A/C Heater Control. A/C And Heater Control - Removal.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Test complete.

8. CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. With the scan tool, check the Environmental Data to help identify the conditions in which the DTC was set.
3. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
4. Wiggle the wiring and connectors while checking for shorted and open circuits.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Test complete.