Temperature Control Inoperative. Buick GL7 (Export) 2000

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2000 🢒 GL7 (Export) 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Temperature Control Inoperative

Temperature Control Inoperative No Airflow for Warm/Cold

Step	Action	Value(s)	Yes	No
1	Did you review the Air Delivery/Temperature Control Circuit Description and perform the necessary inspections?	--	Go to Step 2	Go to Symptoms
2	Verify that the temperature control is inoperative (no airflow for warm/cold). Does the temperature control operate normally?	--	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Place the ignition switch in the RUN position. Using a DMM, probe between the heater-A/C control connector C2 terminal G and ground. Refer to Circuit Testing in Wiring Systems. Move the temperature control knob from hot to cold, and cold to hot. Does the measured voltage vary between approximately 1 and 12 volts?	1-12 V	Go to Step 4	Go to Step 5
4	Disconnect the electric slave actuator connector. Using a DMM, probe between the electric slave actuator connector terminal 10 and ground. Refer to Circuit Testing in Wiring Systems. Is the measured voltage within the specified values?	9-14 V	Go to Step 6	Go to Step 7
5	Check for a poor connection at the heater-A/C control connector C2 terminal G. Refer to Circuit Testing in Wiring Systems. Check for a short to ground or voltage in circuit 733. Refer to Circuit Testing in Wiring Systems. If OK, replace the heater-A/C control. Refer to HVAC Module Assembly Replacement . Is the repair complete?	--	Go to Step 12	--
6	Using a DMM, probe the electric slave actuator connector terminals 10 and 7. Refer to Circuit Testing in Wiring Systems. Is the measured voltage within the specified values?	9-14 V	Go to Step 8	Go to Step 9
7	Repair the poor connection or open in circuit 241 between the electric slave actuator connector terminal 10 and S264. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Is the repair complete?	--	Go to Step 12	--
8	Using a DMM, probe the electric slave actuator connector terminal 8 and ground while moving the temperature control knob. Refer to Circuit Testing in Wiring Systems. Does the measured voltage vary between approximately 1 and 12 volts?	1-12 V	Go to Step 10	Go to Step 11
9	Repair the poor connection or open in circuit 150 between the electric slave actuator connector terminal 7 and S213. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Is the repair complete?	--	Go to Step 12	--
10	Check for a poor connection at the electric slave actuator or a binding air temperature valve. Refer to Circuit Testing in Wiring Systems. If OK, replace the electric slave actuator. Is the repair complete?	--	Go to Step 12	--
11	Repair the poor connection or open in circuit 733 between the electric slave actuator connector terminal 8 and the heater-A/C control connector C2 terminal G. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Is the repair complete?	--	Go to Step 12	--
12	Turn the ignition switch to the OFF position. Reconnect all connectors/components removed. Operate the system in order to verify the repair. Did you correct the condition?	--	System OK	Go to Step 3

Temperature Control Inoperative Front and Rear

Step

Action

Value(s)

Yes

Did you review the Air Delivery/Temperature Control Circuit Description and perform the necessary inspections?

Go to Step 2

Go to Symptoms

Verify that the front and rear temperature controls are inoperative.

Do the temperature controls operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Is the temperature control inoperative from the rear only?

Go to Step 4

Go to Step 5

Turn the rear window wiper/washer and multi-function switch (auxiliary blower switch) to the REAR position.
Disconnect the auxiliary heater-A/C control connector C1.
Place the ignition switch in the RUN position.
Using a DMM, probe between the auxiliary heater-A/C control connector C1 terminal 4 and ground. Refer to Circuit Testing in Wiring Systems.
Move the temperature control knob from hot to cold, and then cold to hot.

Does the measured voltage vary between approximately 1 and 12 volts?

1-12 V

Go to Step 6

Go to Step 7

Is the temperature control inoperative from the front only?

Go to Step 17

Go to Step 18

Using a DMM, probe between the auxiliary heater-A/C control connector C1 terminal 1 and ground. Refer to Circuit Testing in Wiring Systems.

Is the measured voltage within the specified values?

9-14 V

Go to Step 8

Go to Step 9

Repair the poor connection or open in circuit 733 between S252 and the auxiliary heater-A/C control connector C1 terminal 4. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Using a DMM, probe between the auxiliary heater-A/C control connector C1 terminal 6 and B+. Refer to Circuit Testing in Wiring Systems.

Is the measured voltage within the specified values?

9-14 V

Go to Step 10

Go to Step 11

Repair the poor connection or open in circuit 641 between the auxiliary heater-A/C control connector C1 terminal 1 and S345. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Check for a poor connection at the auxiliary heater-A/C control connector C1 terminal 5. Refer to Circuit Testing in Wiring Systems.
Check for a short to ground or voltage in circuit 955. Refer to Circuit Testing in Wiring Systems.
If OK, replace the auxiliary heater-A/C control. Refer to Auxiliary HVAC Module Replacement .

Is the repair complete?

Go to Step 36

Go to Step 12

Repair the poor connection or open in circuit 850 between the auxiliary heater-A/C control connector C1 terminal 6 and S403. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Using a DMM, probe between the temperature valve actuator connector terminal 10 and ground. Refer to Circuit Testing in Wiring Systems.

Is the measured voltage within the specified values?

9-14 V

Go to Step 13

Go to Step 14

Using a DMM, probe the auxiliary temperature valve actuator connector terminal 7 and B+. Refer to Circuit Testing in Wiring Systems.

Is the voltage within the specified values?

9-14 V

Go to Step 15

Go to Step 16

Repair the poor connection or open in circuit 641 between the auxiliary temperature valve actuator connector terminal 10 and S345. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Replace the auxiliary temperature valve actuator. Refer to Temperature Valve Replacement .

Is the repair complete?

Go to Step 36

Repair the poor connection or open in circuit 850 between the auxiliary temperature valve actuator connector terminal 7 and S403. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Place the ignition switch in the RUN position.
Connect a test lamp from the electric slave actuator connector terminal 10 and ground. Refer to Circuit Testing in Wiring Systems.

Is the test lamp on?

Go to Step 19

Go to Step 20

The temperature control is inoperative from both switches.

Were you sent here for a poor cooling concern of the passenger compartment?

Go to Step 25

Go to Step 26

Probe with a test lamp between the electric slave actuator connector terminal 7 and B+. Refer to Circuit Testing in Wiring Systems.

Is the test lamp on?

Go to Step 21

Go to Step 22

Repair the poor connection or open in circuit 241 between the electric slave actuator connector terminal 10 and S264. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Turn the ignition switch to the OFF position.
Disconnect the electric slave actuator connector.
Using a DMM, probe between the heater-A/C control connector C2 terminal G and ground. Refer to Circuit Testing in Wiring Systems.
Move the front switch.

Does the voltage vary between 1-12 volts?

1-12V

Go to Step 23

Go to Step 24

Repair the poor connection or open in circuit 150 between the electric slave actuator connector terminal 7 and S213. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Replace the electric slave actuator.

Is the repair complete?

Go to Step 36

Repair the poor connection or open in circuit 733 between the electric slave actuator connector terminal 8 and S252. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Does the A/C compressor clutch engage when the A/C button is depressed?

Go to Step 27

Go to HVAC Compressor Clutch Does Not Engage

Before proceeding with the following table, check and make sure that:

•	The engine is reaching normal operating temperature.

•	Both upper and lower radiator hoses have become hot.

•	Both inlet and outlet heater hoses have become hot.

•	The cooling system is operating normally.

Is the cooling system operating normally?

Go to Step 27

Go to Cooling Insufficient - Air Conditioning (A/C) System

Disconnect the heater-A/C control connector C2.
Turn the ignition switch to the RUN position.
Connect a test lamp from the heater-A/C control connector C2 terminal E and ground. Refer to Circuit Testing in Wiring Systems.

Is the test lamp on?

Go to Step 28

Go to Step 29

Probe with a test lamp between the heater-A/C control connector C2 terminal C and ground. Refer to Circuit Testing in Wiring Systems.

Is the test lamp on?

Go to Step 30

Go to Step 31

Repair a poor connection or open in circuit 640 between the heater-A/C control connector C2 terminal E and S202. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Turn the ignition switch to the OFF position.
Disconnect the electric slave actuator connector.
Disconnect the auxiliary heater-A/C control connector C1.
Using a DMM, check for continuity in circuit 733 between the heater-A/C control connector C2 terminal G and the electric slave actuator terminal 8. Refer to Circuit Testing in Wiring Systems.
Using a DMM, check for continuity in circuit 733 between the heater-A/C control connector C2 terminal G and the auxiliary heater-A/C control connector C1 terminal 4.

Is there continuity for both tests?

Go to Step 32

Go to Step 33

Repair the poor connection or open in circuit 241 between the heater-A/C control connector C2 terminal C and S264. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Using a DMM, check for continuity in circuit 733 between the heater-A/C control connector C2 terminal G and ground. Refer to Circuit Testing in Wiring Systems.

Is circuit 733 shorted to ground?

Go to Step 34

Go to Step 35

Repair the poor connection or open in circuit 733. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Repair the short to ground in circuit 733. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 36

Replace the heater-A/C control. Refer to HVAC Module Assembly Replacement .

Is the repair complete?

Go to Step 36

Turn the ignition switch to the OFF position.
Reconnect all connectors/components disconnected.
Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3