GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Cruise Control System Check?

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Go to Step 2

Go to Cruise Control System Check

2

  1. Disconnect the cruise control module electrical connector.
  2. Turn the ignition switch to the RUN position.
  3. Connect a test lamp from cavity F on CKT 41 (BRN) to ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 12

3

Connect a test lamp from CKT 41 (BRN) to cavity E on CKT 451 (BLK/WHT) on the cruise control module electrical connector.

Does the test lamp light?

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Go to Step 4

Go to Step 13

4

  1. Move the cruise control switch to the ON position.
  2. Connect a test lamp from cavity E of CKT 84 (DK BLU) to ground.

Does the test lamp light?

--

Go to Step 14

Go to Step 5

5

Connect a test lamp from cavity E of CKT 87 (GRY/BLK) to ground.

Does the test lamp light?

--

Go to Step 16

Go to Step 6

6

Connect a test lamp from cavity A of CKT 397 (GRY) to ground.

Does the test lamp light?

--

Go to Step 7

Go to Step 18

7

Connect a test lamp from cavity D of CKT 379 (BRN/WHT) of the stoplamp switch to ground.

Does the test lamp light?

--

Go to Step 8

Go to Step 22

8

Connect a test lamp between cavity B of CKT 84 (DK BLU) of the cruise control module electrical connector and ground.

Does the test lamp light?

--

Go to Step 9

Go to Step 31

9

Connect a test lamp between cavity G of CKT 1320 (LT BLU) of the cruise control module electrical connector to BAT+.

Does the test lamp light?

--

Go to Step 10

Go to Step 35

10

  1. Raise and support the vehicle. Refer to Vehicle Lifting and Jacking in General Information.
  2. Connect the positive (red) lead of the J 39200 Digital Multimeter (DMM) to cavity K of CKT 817 (DK GRN/WHT).
  3. Connect the negative (black) lead of the J 39200 DMM to cavity E of CKT 452 (BLK/WHT).
  4. Set the J 39200 DMM to measure DC volts.
  5. Push the Hz button on the DMM once.
  6. Start the vehicle.
  7. Depress the brake pedal.
  8. Place the vehicle in a forward gear.
  9. Release the brake.
  10. Accelerate in order to maintain a speed of 25 MPH.

Is the value displayed within the specified range?

25-30 Hz

Go to Step 11

Go to Step 33

11

  1. Turn the ignition switch to the OFF position.
  2. Reconnect the VCM/PCM.
  3. Set the park brake.
  4. Move the cruise control switch to the OFF position.
  5. Move the cruise control switch to the ON position.
  6. Wait at least 3 seconds.
  7. Push in and hold the cruise control SET switch.
  8. Hold the cruise slide switch in the RESUME/ACCEL position.
  9. Fully depress and hold the brake pedal.
  10. Wait 10 seconds.
  11. Release the brake pedal while continuing to hold the RESUME/ACCEL switch and the SET switch.

Did the engine RPM increase momentarily?

--

Go to Step 40

Go to Step 36

12

Locate and repair the open in CKT 41 (BRN) between the cruise control module and the IP fuse block.

Did you complete the repair?

--

Go to Cruise Control System Check

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13

Locate and repair the open in CKT 451 (BLK/WHT) between the cruise control module and ground.

Did you complete the repair?

--

Go to Step 4

--

14

Inspect for a short to voltage in CKT 84 (DK BLU) between the cruise control module and the cruise control switch.

Is the circuit OK?

--

Go to Step 42

Go to Step 15

15

Repair the short to voltage in CKT 84 (DK BLU) between the cruise control module and the cruise control switch.

Did you complete the repair?

--

Go to Step 5

--

16

Inspect for a short to voltage in CKT 87 (GRY/BLK) between the cruise control module and the cruise control switch.

Is the circuit OK?

--

Go to Step 42

Go to Step 17

17

Repair the short to voltage in CKT 87 (GRY/BLK) between the cruise control module and the cruise control switch.

Did you complete the repair?

--

Go to Step 6

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18

  1. Disconnect the cruise control switch from the cruise control module at C211.
  2. Connect a test lamp from CKT 41 (BRN) cavity A13 of C11 to ground.

Does the test lamp light?

--

Go to Step 19

Go to Step 21

19

Inspect the following circuits for an open:

    • CKT 41 (BRN) to the cruise control switch
    • CKT 397 (GRY) between the cruise control module and the cruise control switch

Are the circuits OK?

--

Go to Step 42

Go to Step 20

20

Repair the open in one of the following circuits:

    • CKT 41 (BRN) to the cruise control switch
    • CKT 397 (GRY) between the cruise control module and the cruise control switch

Did you complete the repair?

--

Go to Step 7

--

21

Locate and repair the open in CKT 41 (BRN) between the cruise control switch and splice SP200.

Did you complete the repair?

--

Go to Step 7

--

22

Connect a test lamp from CKT 379 (BRN/WHT) at splice pack SP202 cavity H.

Does the test lamp light?

--

Go to Step 23

Go to Step 26

23

Inspect for an open in CKT 379 (BRN/WHT) between splice pack SP202 and the cruise control module.

Is the circuit OK?

--

Go to Step 25

Go to Step 24

24

Repair the open in CKT 379 (BRN/WHT) between splice pack SP202 and the cruise control module.

Did you complete the repair?

--

Go to Step 8

--

25

Inspect the continuity of splice pack SP202. Repair or replace as necessary.

Did you complete the repair?

--

Go to Step 8

--

26

Connect a test lamp from cavity D of CKT 441 (BRN) at the stoplamp switch to ground.

Does the test lamp light?

--

Go to Step 27

Go to Step 30

27

Inspect the operation of the stoplamp switch.

Is the operation of the stoplamp switch OK?

--

Go to Step 28

Go to Step 29

28

Locate and repair the open in one of the following circuits between splice pack SP202 and the stoplamp switch:

    • CKT 420
    • CKT 379

Did you complete the repair?

--

Go to Step 8

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29

Adjust or replace the stoplamp switch.

Did you complete the repair?

--

Go to Step 8

--

30

Locate and repair the open in CKT 379 (BRN/WHT) between the stoplamp switch and the IP fuse block.

Did you complete the repair?

--

Go to Step 8

--

31

Inspect for an open in CKT 84 (DK BLU) between the cruise control module and the cruise control switch.

Is the circuit OK?

--

Go to Step 42

Go to Step 32

32

Repair the open in CKT 84 (DK BLU) between the cruise control module and the cruise control switch.

Did you complete the repair?

--

Go to Step 9

--

33

Inspect for a short to ground or open in CKT 817 (DK GRN/WHT) between the cruise control module and one of the following components:

    • The VCM
    • The PCM

Is the circuit OK?

--

Go to Step 43

Go to Step 34

34

Repair the short to ground or the open in CKT 817 (DK GRN/WHT) between the cruise control module and one of the following components:

    • The VCM
    • The PCM

Did you complete the repair?

--

Go to Step 11

--

35

  1. Connect a test lamp from cavity G of CKT 1320 (LT BLU) on the cruise control module electrical connector to ground.
  2. Apply the brake.

Does the test lamp light?

--

Go to Step 36

Go to Step 37

36

Locate and repair an open in one of the following circuits:

    • CKT 1320 to CHMSL
    • CKT 17 from the stoplamp switch to the turn signal switch.

Did you complete the repair?

--

Go to Step 10

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37

Inspect Fuse 41 (VEH CHMSL) for an open.

Is the fuse OK?

--

Go to Step 39

Go to Step 38

38

Replace Fuse 41 (VEH CHMSL).

Is the action complete?

--

Go to Step 10

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39

Locate and repair an open in CKT 17 (WHT) from the UBEC to the stoplamp switch.

Did you complete the repair?

--

Go to Step 11

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40

Inspect for proper terminal contact.

Are the contacts clean?

--

Go to Step 43

Go to Step 41

41

Clean the terminal contacts.

Is the action complete?

--

Go to Step 11

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42

Replace the cruise control switch. Refer to Multifunction, Turn Signal and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Tilt.

Did you complete the repair?

--

Go to Cruise Control System Check

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43

Replace the cruise control module. Refer to Cruise Control Module Replacement .

Did you complete the repair?

--

Go to Cruise Control System Check

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