GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The ASR OFF Indicator is controlled by the EBCM by sending class 2 messages to the Instrument Panel Cluster (IPC). It is turned on when the EBCM sets a DTC that turns on the ASR OFF indicator. It is also turned on or off when the Accelerator Slip Regulation (ASR) Switch is pressed. The Electronic Brake Control Module (EBCM) supplies 12 volts to the ASR Switch, when the ASR switch is depressed the EBCM sees the voltage go low, and that the ASR switch state has changed. When the EBCM receives that a switch state has changed it turns on or off the ASR and sends a message to the IPC to turn on or off the ASR OFF indicator depending on its previous state.

Diagnostic Aids

    • It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
    • Thoroughly inspect any circuitry that may be causing the complaint for the following conditions:
       - Backed out terminals
       - Improper mating
       - Broken locks
       - Improperly formed or damaged terminals
       - Poor terminal-to-wiring connections
       - Physical damage to the wiring harness
    • The following conditions may cause an intermittent malfunction:
       - A poor connection
       - Rubbed-through wire insulation
       - A broken wire inside the insulation
    • If an intermittent malfunction exists refer to Inducing Intermittent Fault Conditions in Wiring Systems for further diagnosis.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Checks if EBCM is receiving a ASR switch message from the switch.

  2. Check if the scan tool can turn on and off the indicator lamps in the instrument cluster.

  3. Checks if the EBCM or ASR Switch is at fault.

Step

Action

Value(s)

Yes

No

Schematic Reference: Antilock Brake System Schematics

1

Did you perform the Diagnostic System Check ?

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Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Turn the ignition switch to the RUN position, engine off.
  2. Using a scan tool enter TCS Data List.
  3. While monitoring the TCS On/Off switch status, press and release the ASR On/Off switch.

Does the switch status change from pressed to released as the ASR switch is pressed and released?

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Go to Step 3

Go to Step 5

3

  1. Using a scan tool in the Instrument Cluster Special Function.
  2. Go to Displays Test in Output Control.
  3. In the Displays Testmode you can turn on or off the instrument panel indicators.
  4. All indicators will turn ON when commanded on.

Does the ASR OFF indicator turn on then off?

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Go to Step 11

Go to Step 4

4

  1. Disconnect instrument cluster and connect a test light across the appropraiate power and ground terminals.
  2. Test light OFF, repair open in power or ground circuit to cluster.
  3. Test light ON, check connector for poor connection to Cluster.
  4. If OK, replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console.

Is the instrument cluster replacement complete?

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Go to Diagnostic System Check - ABS

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5

  1. Remove the ASR switch and disconnect the connector. Refer to Electronic Traction Control Switch Replacement .
  2. Using a scan tool in ABS/TC Data List read the TCS switch status.
  3. Connect a jumper wire between terminals E and  F of the ASR Switch harness connector.

Does the TCS switch status read pressed with the jumper wire connected?

--

Go to Step 6

Go to Step 7

6

Replace the ASR switch. Refer to Electronic Traction Control Switch Replacement .

Is the replacement complete?

--

Go to Diagnostic System Check - ABS

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7

  1. Turn the ignition switch to the OFF position.
  2. Using DMM, measure the resistance between the ASR switch harness connector terminal F and a known good ground.

Is the resistance within the range specified in the value(s) column?

0-5 ohms

Go to Step 9

Go to Step 8

8

Repair the ground circuit for a open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

9

  1. Disconnect the EBCM Connector C1
  2. Install the J 39700 Universal Pinout box using the J 39700-530 Cable Adapter to connector C1 only.
  3. Using DMM, measure the resistance between the ASR switch harness connector terminal E and 17 of J 39700 .
  4. Is the resistace within the range specified in the value(s) column?

0-5 ohms

Go to Step 11

Go to Step 10

10

Repair traction control switch signal circuit for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

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11

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Is the replacement complete?

--

Go to Diagnostic System Check - ABS

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