GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The steering wheel temperature switch will not adjust HVAC temperatures and no DTC's have been set.

1

Did you perform the HVAC Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn ON the radio.
  3. Press each entertainment steering wheel control switch.

Do the entertainment steering wheel controls function?

--

Go to Step 3

Go to Symptoms - Entertainment in Entertainment

3

    Caution: Refer to SIR Caution in the Preface section.

  1. Disable the SIR system. Refer to SIR Disabling and Enabling in SIR.
  2. Turn OFF the ignition.
  3. Disconnect the radio. Refer to Radio Replacement in Entertainment.
  4. Turn ON the ignition, with the engine OFF.
  5. Measure the voltage from the remote radio control signal circuit to a good ground.
  6. Press the TEMP UP and TEMP DOWN steering wheel control switches.

Does the voltage change for each switch pressed?

--

Go to Step 4

Go to Step 17

4

Is the vehicle equipped with a remote playback device-CD changer?

--

Go to Step 5

Go to Step 6

5

  1. Turn OFF the ignition.
  2. Connect the radio.
  3. Turn ON the ignition, with the engine OFF.
  4. Operate the CD changer functions from the radio.

Do the CD changer controls function?

--

Go to Step 10

Go to Symptoms - Entertainment in Entertainment

6

  1. Turn OFF the ignition.
  2. Connect the radio.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage from the entertainment and comfort serial data circuit of the DLC connector to a good ground.

Is the voltage greater than the specified value?

3 V

Go to Step 7

Go to Step 9

7

  1. Turn OFF the ignition.
  2. Disconnect the instrument panel integration module. Refer to Instrument Panel Module Replacement in Body Control System.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage from the entertainment and comfort serial data circuit of the DLC connector to a good ground.

Is the voltage greater than the specified value?

3 V

Go to Step 8

Go to Step 13

8

  1. Turn OFF the ignition.
  2. Disconnect the radio. Refer to Radio Replacement in Entertainment.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage from the entertainment and comfort serial data circuit of the DLC connector to a good ground.

Is the voltage greater than the specified value?

3 V

Go to Step 11

Go to Step 14

9

  1. Turn OFF the ignition.
  2. Disconnect the instrument panel integration module. Refer to Instrument Panel Module Replacement in Body Control System.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage from the entertainment and comfort serial data circuit of the DLC connector to a good ground.

Is the voltage greater than the specified value?

3 V

Go to Step 16

Go to Step 12

10

Test the entertainment and comfort serial data circuit for an open between the radio and the instrument panel integration module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 20

Go to Step 11

11

Test the entertainment and comfort serial data circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 20

Go to Step 12

12

Test the entertainment and comfort serial data circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 20

Go to Step 15

13

Test the entertainment and comfort serial data circuit for a short to ground or an open between the radio and the instrument panel integration module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 20

Go to Step 15

14

Test the entertainment and comfort serial data circuit for a short to ground or an open between the radio and the instrument panel integration module (IPM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 20

Go to Step 16

15

Inspect for poor connections at the harness connector of the radio. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 20

Go to Step 18

16

Inspect for poor connections at the harness connector IPM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 20

Go to Step 19

17

Replace the steering wheel control-right. Refer to Steering Wheel Control Switch Assembly Replacement in Steering Wheel and Column.

Did you complete the replacement?

--

Go to Step 20

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18

Replace the radio. Refer to Radio Replacement in Entertainment.

Did you complete the replacement?

--

Go to Step 20

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19

Important:: Perform the recalibration procedure for the IPM.

Replace the IPM. Refer to Instrument Panel Module Replacement in Body Control System.

Did you complete the replacement?

--

Go to Step 20

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20

Enable the SIR system. Refer to SIR Disabling and Enabling in SIR.

Is the SIR system enabled?

--

Go to Step 21

--

21

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2