GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 Regal (China) 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Temperature Control Inoperative

Step

Action

Value(s)

Yes

No

1

Inspect the fuse B3-B4 in the fuse block.

Is the fuse open?

--

Go to Step 2

Go to Step 3

2

Repair a short to ground in circuit 41.

Is the repair complete?

--

Go to Functional Check

--

3
  1. Turn the ignition switch to the RUN position.
  2. Using a Digital Multimeter (DMM), backprobe between the HVAC control assembly harness connector C2 terminal G and ground.
  3. Move the temperature control knob from WARM to COOL and COOL to WARM.

Does the measured voltage vary within the specified range?

1-12 V

Go to Step 4

Go to Step 5

4
  1. Disconnect the front left temperature actuator connector.
  2. Connect a DMM, between the front left temperature actuator harness connector terminal 10 and ground.

Is the measured voltage within the specified range?

9-14 V

Go to Step 6

Go to Step 7

5
  1. Disconnect the HVAC control assembly harness connector C2.
  2. Connect a DMM between the HVAC control assembly connector C2 terminal C and ground.
  3. Turn the ignition switch to the RUN position.

Is the measured voltage within the specified range?

9-14 V

Go to Step 13

Go to Step 12

6

Connect a DMM between the front left temperature actuator harness connector between terminal 10 and terminal 7 .

Is the measured voltage within the specified range?

9-14 V

Go to Step 8

Go to Step 9

7

Repair a poor connection or an open in circuit 41 between S233 and the front left temperature actuator harness connector terminal 10.

Is the repair complete?

--

Go to Functional Check

--

8
  1. Connect a DMM between the front left temperature actuator harness connector terminal 8 and ground.
  2. Turn the ignition switch to the RUN position.
  3. Move the temperature control knob from WARM to COOL and COOL to WARM.

Does the measured voltage vary within the specified range?

1-12 V

Go to Step 10

Go to Step 11

9

Repair a poor connection or an open in circuit 1450 between the front left temperature actuator harness connector terminal 7 and G200.

Is the repair complete?

--

Go to Functional Check

--

10
  1. Inspect for a poor connection at the front left temperature actuator.
  2. Inspect for a binding air temperature valve.
  3. If connections are OK and no binding is found, replace the front left temperature actuator. Refer to Temperature Actuator Replacement .

Is the repair complete?

--

Go to Functional Check

--

11

Repair a poor connection or an open in circuit 1199

Is the repair complete?

--

Go to Functional Check

--

12

Repair a poor connection or an open in circuit 41 between S233 and the HVAC control assembly harness connector C2 terminal C.

Is the repair complete?

--

Go to Functional Check

--

13
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the front left temperature actuator connector.
  3. Using a DMM, test for a short to ground in circuit 1199.

Is the circuit shorted to ground?

--

Go to Step 14

Go to Step 15

14

Repair a short to ground in circuit 1199.

Is the repair complete?

--

Go to Functional Check

--

15

Replace the front HVAC control assembly. Refer to Control Assembly Replacement .

Is the repair complete?

--

Go to Functional Check

--