GM Service Manual Online
For 1990-2009 cars only

Mode Actuator Inoperative FRONT

Step

Action

Value(s)

Yes

No

1

Has the HVAC Air Delivery System Check been performed?

--

Go to Step 2

Go to HVAC Air Delivery System Check

2

  1. Place the ignition switch in the RUN position.
  2. Disconnect the connector at the front mode door motor.
  3. Connect a DMM (volts) between the front mode door motor connector, cavity 10, and ground.

Is battery voltage present?

--

Go to Step 4

Go to Step 3

3

Locate and repair the open in CKT 141 (BRN) between the IP fuse block and the front mode door motor. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to HVAC Air Delivery System Check

--

4

Connect a DMM (continuity) between the front mode door motor connector, cavity 7, and ground.

Is continuity present?

--

Go to Step 6

Go to Step 5

5

Locate and repair the open in CKT 150 (BLK) between the front mode door motor and splice S244. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to HVAC Air Delivery System Check

--

6

  1. Place the ignition switch in the RUN position.
  2. Place the blower switch on the HVAC control module in the LO position.
  3. Make sure that the front blower motor is operating.
  4. Connect a DMM (volts) from the front mode door motor connector, cavity 8, to ground.
  5. Adjust the position of the mode control dial while observing the DMM response.

Is the DMM response a smooth, variable voltage?

--

Go to Step 9

Go to Step 7

7

  1. Disconnect connector C3 at the HVAC control module.
  2. Connect a DMM (volts) between pin 9 of the HVAC control module, and ground.
  3. Adjust the position of the mode control dial while observing the DMM response.

Is the DMM response a smooth, variable voltage?

--

Go to Step 8

Go to Step 10

8

Locate and repair the open or cause of resistance in CKT 454 (WHT) between the HVAC control module and the front mode door motor. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to HVAC Air Delivery System Check

--

9

Replace the front mode door motor. Refer to Mode Actuator Replacement .

Is the repair complete?

--

Go to HVAC Air Delivery System Check

--

10

Replace the HVAC control module. Refer to Control Assembly Replacement .

Is the repair complete?

--

Go to HVAC Air Delivery System Check

--