GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the turn signal lamps are inoperative.

Do the turn signal lamps operate normally?

--

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

Go to Step 3

3

Inspect the TURN fuse 10 at the IP fuse block.

Is the fuse open?

--

Go to Step 4

Go to Step 5

4

Locate and repair the short to ground in CKT 139 (PNK), CKT 16 (PPL), CKT 1414 (LT BLU/WHT), and/or CKT 1415 (DK BLU/WHT). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

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5

Do the activated turn signals stay on steady at all locations?

--

Go to Step 9

Go to Step 6

6

  1. Turn the ignition switch to the RUN position.
  2. Backprobe a test lamp between CKT 139 (PNK) cavity C and ground at the hazard switch connector. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 7

7

Locate and repair the open or high resistance in CKT 139 (PNK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

--

8

  1. Connect a test lamp between CKT 16 (PPL) cavity H at the hazard switch connector and ground. Refer to Circuit Testing in Wiring Systems.
  2. Maintain the ignition switch in the RUN position.

Does the test lamp illuminate?

--

Go to Step 12

Go to Step 9

9

Using a J 39200 Digital Multimeter (DMM), check for continuity to ground at terminal A of the hazard warning switch. Refer to Circuit Testing in Wiring Systems.

Is continuity present?

--

Go to Step 11

Go to Step 10

10

Locate and repair the open or high resistance in CKT 1850. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

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11

Replace the hazard warning switch. Refer to Hazard Warning Switch Replacement .

Is the repair complete?

--

Go to Step 25

--

12

  1. Connect a test lamp between CKT 16 (PPL) cavity B5 at connector C211 and ground. Refer to Circuit Testing in Wiring Systems.
  2. Maintain the ignition switch in the RUN position.

Does the test lamp illuminate?

--

Go to Step 14

Go to Step 13

13

Locate and repair the open or high resistance in CKT 16 (PPL).

Is the repair complete?

--

Go to Step 25

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14

  1. Maintain the ignition switch in the RUN position.
  2. Connect a test lamp between ground and terminal A6 (DK BLU/WHT) at the C211 connector while activating the RH turn signal. Refer to Circuit Testing in Wiring Systems.
  3. Connect a test lamp between ground and terminal A7 (LT BLU/WHT) at the C211 connector while activating the LH turn signal. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 16

Go to Step 15

15

Replace the Multifunction Switch (Turn Signal Switch). Refer to Turn Signal Switch Replacement - On Vehicle in Steering Wheel and Column - Tilt.

Is the repair complete?

--

Go to Step 25

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16

  1. Maintain the ignition switch in the RUN position.
  2. Connect a test lamp between ground and the underhood fuse block connector C1, terminals C2 and  C10 while activating the RH turn signal. Refer to Circuit Testing in Wiring Systems.
  3. Connect a test lamp between ground the underhood fuse block connector C1, terminals C1 and F10 while activating the LH turn signal. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 18

Go to Step 17

17

Locate and repair the open or high resistance in CKT 1414 (LT BLU/WHT) and/or CKT 1415 (DK BLU/WHT). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

--

18

Inspect the following fuses in the underhood fuse block:

    • RH TURN
    • RH REAR TURN
    • LH TURN
    • LH REAR TURN

Are all the fuses good?

--

Go to Step 20

Go to Step 19

19

Locate and repair the short to ground in the applicable circuit(s). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

--

20

Using a test lamp to ground, check each of the following for voltage while activating the appropriate turn signal switch mode. Refer to Circuit Testing in Wiring Systems.

    • Turn signal lamp, RF terminal A
    • Auxiliary Side Front Turn Signal Lamp, RH terminal A
    • Turn signal lamp, RR terminal A
    • Turn signal lamp, LF terminal A
    • Auxiliary Side Front Turn Signal Lamp, LH terminal A
    • Turn signal lamp, LR terminal A

Does the test lamp illuminate?

--

Go to Step 22

Go to Step 21

21

Locate and repair the open or high resistance in the applicable circuit(s). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

--

22

Using a J 39200 DMM, check each of the following for ground continuity:

    • Turn signal lamp, RF terminal G
    • Auxiliary Side Front Turn Signal Lamp, RH terminal B
    • Turn signal lamp, RR terminal B
    • Turn signal lamp, LF terminal G
    • Auxiliary Side Front Turn Signal Lamp, LH terminal B
    • Turn signal lamp, LR terminal B

Is there continuity?

--

Go to Step 24

Go to Step 23

23

Locate and repair the open or high resistance in the applicable ground circuit(s).

Is the repair complete?

--

Go to Step 25

--

24

Replace the inoperative bulbs.

Is the repair complete?

--

Go to Step 25

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25

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3