GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 SSR 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Cruise Control Inoperative/Malfunctioning

Diagnostic Aids
    • Inspect for proper operation of the stop lamps. Refer to Exterior Lighting Systems Description and Operation in Lighting Systems.
    • Ensure that the following cruise control switches are not stuck or sticking in the engaged position:
       - Set/Coast
       - Resume/Accel
    • For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Conditions for Enabling Cruise Control
    • The vehicle speed is greater than 40 km/h (25 mph).
    • The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear.
    • The system voltage is between 12-16 volts.

Step

Action

Yes

No

Schematic Reference : Cruise Control Schematics

Connector End View Reference: Engine Control Module Connector End Views in Engine Controls - 6.0L

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Turn the cruise control On/Off switch OFF.
  4. With the scan tool, observe the Cruise On/Off Switch parameter in the engine control module (ECM) Cruise Control Data list.

Does the Cruise On/Off Switch parameter display Off?

Go to Step 3

Go to Step 8

3

With the scan tool, observe the following cruise control switch parameters in the engine control module (ECM) Cruise Control Data list:

    • Cruise Resume/Accel. Switch
    • Cruise Set/Coast Switch

Do any of the cruise control switch parameters listed above display Applied?

Go to Step 9

Go to Step 4

4
  1. Turn the cruise control On/Off switch ON.
  2. With the scan tool, observe the Cruise On/Off Switch parameter.

Does the Cruise On/Off Switch parameter display On?

Go to Step 5

Go to Step 10

5
  1. With the scan tool, observe the Cruise Set/Coast Switch parameter.
  2. Press and hold the cruise control Set/Coast button.

Does the Cruise Set/Coast Switch parameter Display Applied?

Go to Step 6

Go to Step 13

6
  1. With the scan tool, observe the Cruise Resume/Accel. Switch parameter.
  2. Press and hold the cruise control Resume/Accel switch.

Does the Cruise Resume/Accel. Switch parameter Display Applied?

Go to Step 7

Go to Step 12

7

Do the stop lamps work properly?

Go to Step 22

Go to Stop Lamps Always On or Stop Lamps Inoperative in Lighting Systems

8
  1. Turn OFF the ignition.
  2. Disconnect C4 of the multifunction, turn signal switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the Cruise On/Off Switch parameter.

Does the Cruise On/Off Switch parameter display On?

Go to Step 14

Go to Step 19

9
  1. Turn OFF the ignition.
  2. Disconnect C4 of the multifunction turn signal switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the following cruise control switch parameters in the engine control module (ECM) Cruise Control Data list:
    5. • Cruise Resume/Accel. Switch
    • Cruise Set/Coast Switch

Do any of the cruise control switch parameters listed above display Applied?

Go to Step 15

Go to Step 19

10
  1. Turn OFF the ignition.
  2. Disconnect C4 of the multifunction, turn signal switch.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the ignition 3 voltage circuit and a good ground.

Does the test lamp illuminate?

Go to Step 11

Go to Step 21

11
  1. Turn the ignition OFF.
  2. Connect a 3-amp fused jumper between the ignition 3 voltage circuit and the cruise control on switch signal circuit.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the Cruise On/Off Switch parameter.

Does the Cruise On/Off Switch parameter display On?

Go to Step 19

Go to Step 16

12
  1. Turn OFF the ignition.
  2. Disconnect C4 of the multifunction, turn signal switch.
  3. Connect a 3-amp fused jumper between the ignition 3 voltage circuit and the cruise control resume/accel switch signal circuit.
  4. Turn ON the ignition, with the engine OFF.
  5. With the scan tool, observe the Cruise Resume/Accel. Switch parameter.

Does the Cruise Resume/Accel. Switch parameter display Applied?

Go to Step 19

Go to Step 18

13
  1. Turn OFF the ignition.
  2. Disconnect C4 of the multifunction, turn signal switch.
  3. Connect a 3-amp fused jumper between the ignition 3 voltage circuit and the cruise control set/coast switch signal circuit.
  4. Turn ON the ignition, with the engine OFF.
  5. With the scan tool, observe the Cruise Set/Coast Switch parameter.

Does the Cruise Set/Coast Switch parameter display Applied?

Go to Step 19

Go to Step 17

14

Test the cruise control on switch signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 20

15

Test the cruise control switch signal circuit that displayed Applied on the scan tool for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 20

16

Test the cruise control on switch signal circuit for the following:

    • Open
    • Short to ground
    • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 20

17

Test the cruise control set/coast switch signal circuit for the following:

    • Open
    • Short to ground
    • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 20

18

Test the cruise control resume/accelerate switch signal circuit for the following:

    • Open
    • Short to ground
    • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 20

19

Inspect for poor connections at C4 of the multifunction, turn signal 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 25

Go to Step 23

20

Inspect for poor connections at the harness connector of the ECM. 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 25

Go to Step 24

21

Repair the following in the ignition 3 voltage circuit.

    • Open
    • Short to ground
    • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

--

22

Repair the open or the high resistance in the center high mounted stop lamp (CHMSL) supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

--

23

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

Did you complete the replacement?

Go to Step 25

--

24

Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 25

--

25

Operate the vehicle within the conditions for cruise control operation.

Does the cruise control system operate properly?

System OK

Go to Step 2