GM Service Manual Online
For 1990-2009 cars only

Turn Signal Lamps and/or Indicators Always On or Flashing Export

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

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

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn ON the ignition, with the engine OFF.
  2. Observe the turn signal lamps and indicators.
  3. Turn ON and OFF the right and left turn signal lamps.

Do the turn signal lamps and indicators operate properly?

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

Go to Step 3

3

Disconnect the connector C201.

Are any turn signal lamps illuminated?

Go to Step 6

Go to Step 5

4

Test for a short to battery positive voltage in the turn signal/hazard flasher module voltage supply circuit.

Did you find and correct the condition?

Go to Step 7

Go to Step 6

5

Repair the short to battery positive voltage in the supply voltage circuit of the illuminated turn signal lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

--

6

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

Did you complete the replacement?

Go to Step 7

--

7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2

Turn Signal Lamps and/or Indicators Always On or Flashing Domestic

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

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

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Cover the ambient light sensor with a dark soft cloth.
  2. Turn the ignition to the ON position, with the engine OFF.
  3. Observe the turn signal lamps and indicators.
  4. Place the turn signal switch in the OFF position.

Are the turn signal lamps and indicators off?

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

Go to Step 3

3

Are any of the turn signals lamps flashing?

Go to Step 11

Go to Step 4

4

Important: The turn signal indicator will illuminate if the same side rear turn signal bulb is inoperative and the park lamps are ON.

Is only the turn signal indicator illuminated?

Go to Turn Signal Lamps and/or Indicators Inoperative

Go to Step 5

5

Are the front turn signals always on?

Go to Step 6

Go to Step 10

6

Are the automatic headlamps illuminated?

Go to Step 7

Go to Daytime Running Lamps (DRL) Inoperative

7

Disconnect the daytime running lights control module connector.

Are the front turn signals illuminated?

Go to Step 9

Go to Step 8

8

Test for a short to voltage in the affected turn signal switch signal circuit of the daytime running lamps control module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 12

9

Repair the short to battery positive voltage in the supply voltage circuit of the affected front turn signal lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 13

--

10

Repair the short to battery positive voltage in the supply voltage circuit of the affected lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 13

--

11

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

Did you complete the replacement?

Go to Step 13

--

12

Replace the Daytime Running Lamps (DRL) control module. Refer to Daytime Running Lights (DRL) Control Module Replacement .

Did you complete the repair?

Go to Step 13

--

13

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2