GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The headlamp switch in the AUTO position provides a ground for the twilight sentinel delay signal circuit. The instrument panel module (IPM) determines the switch position based on the status of the headlamp switch.

Conditions for Running the DTC

The IPM is powered.

Conditions for Setting the DTC

The twilight sentinel delay signal voltage is less than 0.02 volts.

Action Taken When the DTC Sets

Auto status set to ON.

Conditions for Clearing the DTC

The IPM does not detect a voltage that is less than the predetermined value.

Step

Action

Value(s)

Yes

No

Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Lighting Systems Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Position the headlamp switch to the AUTO position.
  4. With a scan tool, observe the Twilight Delay Pot data parameter in the instrument panel module (IPM) Open/Short data list.

Does the scan tool indicate that the Twilight Delay Pot data parameter is more the specified value?

0.02 V

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

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the turn signal/multifunction switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Twilight Delay Pot data parameter.

Does the scan tool indicate that the Twilight Delay Pot data parameter is less than the specified value?

0.02 V

Go to Step 4

Go to Step 5

4

Test the twilight sentinel delay signal circuit of the turn signal/multifunction switch for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 9

Go to Step 6

5

Inspect for poor connections at the harness connector of the turn signal/multifunction switch. 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 9

Go to Step 7

6

Inspect for poor connections at the harness connector of the 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 9

Go to Step 8

7

Replace the turn signal/multifunction switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.

Did you complete the replacement?

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Go to Step 9

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8

Important:: Perform the setup procedure for the IPM after IPM replacement.

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

Did you complete the replacement?

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Go to Step 9

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9

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

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Go to Step 2

System OK