Cruise Control Inoperative. GMC Truck GMC K Sierra

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC K Sierra - 4WD 🢒 Engine 🢒 Engine Controls - 4.8L, 5.3L, and 6.0L 🢒 Cruise Control Inoperative

Step

Action

Value(s)

Yes

Important:

•	Inspect the condition of the following fuses:

The BRAKE

-	The STOP LPS

-	The VEH STOP

-	The CRUISE

•	If you find any open fuse, locate and repair the source of the overload.

•	Inspect for any set powertrain DTCs. Refer to the appropriate DTC list from the following list:

-	Diagnostic Trouble Code (DTC) List in Engine Controls - 4.3L

-	Diagnostic Trouble Code (DTC) List in Engine Controls - 4.8L, 5.3L, 6.0L

•	Inspect for any set antilock brake (ABS) DTCs. Refer to Diagnostic Trouble Code (DTC) List in Antilock Brake System

•	Verify that ground G103 is clean and tight.

•	Inspect the cruise control linkage for loose, binding or improper adjustment.

Turn the ignition OFF.
Ensure that the cruise control switch is in the OFF position.
Disconnect the cruise control module.
Turn the ignition switch to the ON position.
Connect a test lamp (back probe) from terminal A13 CKT 41 (BRN) at the cruise control switch to ground.

Does the test lamp light?

Go to Step 3

Go to Step 2

Locate and repair the open in CKT 41 (BRN).

Is the repair complete?

System OK

Connect a test lamp from the terminal F (BRN) wire at the cruise control module connector to ground.

Does the test lamp light?

Go to Step 4

Go to Step 2

Connect a self powered test lamp between the cruise control module connector cavity E for CKT 451 (BLK/WHT) and ground.

Is there continuity?

Go to Step 6

Go to Step 5

Locate and repair the open in CKT 451 (BLK/WHT).

Is the repair complete?

System OK

Turn the ignition OFF.
Connect a self powered test lamp from terminal A CKT 397 (GRY) at the cruise control module connector to ground.

Does the test lamp light?

Go to Step 7

Go to Step 8

Locate and repair the short to ground in CKT 397 (GRY).

Is the repair complete?

System OK

Connect a self powered test lamp from terminal B CKT 84 (DK BLU) wire at the cruise control module connector to ground.

Does the test lamp light?

Go to Step 9

Go to Step 10

Locate and repair the short to ground in CKT 84 (DK BLU).

Is the repair complete?

System OK

Connect a self powered test lamp from terminal C CKT 87 (GRY/BLK) at the cruise control module connector to ground.

Does the test lamp light?

Go to Step 11

Go to Step 12

Locate and repair the short to ground in CKT 87 (GRY/BLK).

Is the repair complete?

System OK

Turn the ingition switch to the ON position.
Ensure the cruise control switch is OFF.
Connect a test lamp from terminal A CKT 397 (GRY) at the cruise control module connector to ground.

Does the test lamp light?

Go to Step 13

Go to Step 16

Locate the short to voltage in CKT 397 (GRY).

Did you find a short to voltage?

Go to Step 14

Go to Step 15

Repair the short to voltage in CKT 397 (GRY).

Is the repair complete?

System OK

Replace the cruise control switch.

Is the repair complete?

System OK

Connect a test lamp from terminal B CKT 84 (DK BLU) at the cruise control module to ground.

Does the test lamp light?

Go to Step 17

Go to Step 20

Locate the short to voltage in CKT 84 (DK BLU).

Did you find a short to voltage?

Go to Step 18

Go to Step 19

Repair the short to voltage in CKT 84 (DK BLU).

Is the repair complete?

System OK

Replace the cruise control switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle

Is the repair complete?

System OK

Connect a test lamp from terminal C CKT 87 (GRY/BLK) at the cruise control module to ground.

Does the test lamp light?

Go to Step 21

Go to Step 24

Locate the short to voltage in CKT 87 (GRY/BLK).

Did you find a short to voltage?

Go to Step 22

Go to Step 23

Repair the short to voltage in CKT 87 (GRY/BLK).

Is the repair complete?

System OK

Replace the cruise control switch.

Is the repair complete?

System OK

Turn the cruise control switch to ON.
Connect a test lamp from terminal A CKT 397 (GRY) at the cruise control module to ground.

Does the test lamp light?

Go to Step 28

Go to Step 25

Locate the open in CKT 397 (GRY).

Did you find an open?

Go to Step 26

Go to Step 27

Repair the open in CKT 397 (GRY).

Is the repair complete?

System OK

Replace the cruise control switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle

Is the repair complete?

System OK

Connect a test lamp from terminal B CKT 84 (DK BLU) at the cruise control module connector to ground.
While probing the terminal, push the SET button.

Does the test lamp light?

Go to Step 32

Go to Step 29

Locate the open in CKT 84 (DK BLU).

Did you find an open?

Go to Step 30

Go to Step 31

Repair the open in CKT 84 (DK BLU).

Is the repair complete?

System OK

Replace the cruise control switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle

Is the repair complete?

System OK

Connect a test lamp from terminal G CKT 1320 (LT BLU) at the cruise control module connector to ground.
While probing the terminal, depress the brake pedal.

Does the test lamp light when brake pedal is depressed?

Go to Step 34

Go to Step 33

Locate and repair open CKT 1320 (LT BLU) between the underhood bussed electrical center (UBEC) and the cruise control module connector.

Is the repair complete?

System OK

Connect a test lamp from terminal D CKT 379 (BRN/WHT) at the cruise control module connector to ground.

Does the test lamp light?

Go to Step 45

Go to Step 35

Is the vehicle equipped with a manual transmission?

Go to Step 36

Go to Step 40

Connect a test lamp from terminal B CKT 379 (BRN/WHT) of the clutch pedal position (CPP) switch to ground.

Does the test lamp light?

Go to Step 37

Go to Step 38

Locate and repair the open in CKT 379 (BRN/WHT) between the CPP switch and the cruise control module.

Is the repair complete?

System OK

Connect a test lamp from terminal A CKT 420 (PPL) of the CPP switch to ground.

Does the test lamp light?

Go to Step 39

Go to Step 40

Replace the CPP switch. Refer to Clutch Pedal Engine Start Switch Replacement

Is the repair complete?

System OK

Connect a test lamp from terminal C CKT 420 (PPL) at the stoplamp switch to ground.

Does the test lamp light?

Go to Step 41

Go to Step 42

Locate and repair the open in CKT 420 (PPL) or CKT 379 (BRN/WHT).

Is the repair complete?

System OK

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

Does the test lamp light?

Go to Step 44

Go to Step 43

Locate and repair the open in CKT 441 (BRN) between the left bussed electrical center (LBEC) and the stoplamp switch.

Is the repair complete?

System OK

Replace the stoplamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Is the repair complete?

System OK

While probing terminal D CKT 379 (BRN/WHT) at the cruise control module connector to ground, depress the brake pedal.

Does the test lamp go out?

Go to Step 47

Go to Step 46

Replace the stoplamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Is the repair complete?

System OK

Turn the ignition OFF.
Connect a self powered test lamp between terminal K at the cruise control module and terminal F5 of C2 at the mid bussed electrical center (MBEC).

Does the test lamp light?

Go to Step 48

Go to Step 51

Inspect all of the connections at the following components:

•	The cruise control module

•

The MBEC

•	The vehicle control module/powertrain control module

•	All of the inline connectors

Did you find a problem?

Go to Step 49

Go to Step 50

Repair the appropriate component(s).

Is the repair complete?

System OK

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

Is the repair complete?

System OK

Locate and repair the open CKT 817 (DK GRN/WHT) between the cruise control module and the MBEC.

Is the repair complete?

System OK