GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Epica 🢒 Accessories 🢒 Cruise Control 🢒 Cruise Control Inoperative/Malfunctioning

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. The electromagnetic clutch in the cruise control module is grounded through the brake lamps.

Step

Action

Values

Yes

No

1

Visually inspect the cruise control system and verify the following conditions:

    • The electrical connector is correctly attached to the cruise control module.
    • The module and the bracket are not loose.
    • The cable is not bent or kinked.
    • The cable adjuster is correctly attached to its bracket.
    • The cable and bushing are correctly attached to the accelerator assembly.
    • The cable is properly adjusted.

Have all of the above conditions been verified?

--

Go to Step 3

Go to Step 2

2

Make repairs to the components of the cruise control system that were faulty in Step 1.

Is the repair complete?

--

System OK

--

3

Connect a scan tool to the data link connector (DLC).

Does the scan tool display any engine control module (ECM) DTCs?

--

Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 2.5L

Go to Step 4

4

Does the scan tool display any automatic transmission DTCs?

--

Go to Diagnostic Trouble Code (DTC) List/Type in Automatic Transmission - ZF 4HP 16

Go to Step 5

5

Observe the brake lamps when the brakes are being applied.

Do the brake lamps turn ON when the brakes are applied and turn OFF when the brakes are not applied?

--

Go to Step 8

Go to Step 6

6

Inspect the brake lamp switch adjustment. Refer to Stop Lamp Switch Adjustment in Lighting Systems.

Did the switch adjustment correct the condition?

--

System OK

Go to Step 7

7

Repair the brake lamp system.

Does the cruise control operate after the brake lamp system has been repaired?

--

System OK

Go to Step 8

8

Inspect fuses F4 and F19.

Is either fuse blown?

--

Go to Step 9

Go to Step 10

9
    • Inspect for a short circuit and repair it, if necessary.
    • Replace the blown fuses.

Is the repair complete?

--

System OK

--

10
  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage at fuses F4 and F19.

Is the voltage equal to the specified value?

11-14 V

Go to Step 12

Go to Step 11

11

Repair the power supply to the fuses.

Is the repair complete?

--

System OK

--

12
  1. Disconnect the electrical connector from the cruise control module.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage at terminal 3 of the cruise control module connector.

Is the voltage equal to the specified value?

11-14 V

Go to Step 14

Go to Step 13

13

Repair the open circuit between fuse F4 and cruise control module, connector terminal 3.

Is the repair complete?

--

System OK

--

14

With the electrical connector still removed from the cruise control module, use an ohmmeter to measure the resistance between cruise control module connector terminal 6 and ground.

Is the resistance equal to the specified value?

0 ohms

Go to Step 16

Go to Step 15

15

Repair the open circuit between ground and terminal 6 of the cruise control module connector.

Is the repair complete?

--

System OK

--

16

With the electrical connector still removed from the cruise control module, use an ohmmeter to measure the resistance between connector terminal 8 and the brake switch terminal 4.

Is the resistance equal to the specified value?

0 ohms

Go to Step 18

Go to Step 17

17

Repair the open circuit between the cruise control module connector terminal 8 and the brake switch terminal 4.

Is the repair complete?

--

System OK

--

18
  1. Turn ON the ignition, with the engine OFF.
  2. With the electrical connector still removed from the cruise control module, use an voltmeter to measure the voltage at terminal 8 of the cruise control module connector when the brakes are being applied.

Is the voltage equal to the specified value?

11-14 V

Go to Step 20

Go to Step 19

19

Repair the open circuit between brake switch terminal 4 and terminal 8 of the cruise control module connector.

Is the repair complete?

--

System OK

--

20
  1. Turn ON the ignition, with the engine OFF.
  2. Turn the cruise control switch OFF.
  3. With the electrical connector still removed from the cruise control module, use a voltmeter to measure the voltage at terminal 9 of the connector.

Is the voltage equal to the specified value?

0 V

Go to Step 22

Go to Step 21

21

Repair the short to voltage between the cruise control main switch and the cruise control module connector terminal 9.

Is the repair complete?

--

System OK

--

22
  1. Turn ON the ignition, with the engine OFF.
  2. Turn the cruise control switch ON.
  3. With the electrical connector still removed from the cruise control module, use a voltmeter to measure the voltage at terminal 9 of the connector.

Is the voltage equal to the specified value?

11-14 V

Go to Step 24

Go to Step 23

23

Repair the open circuit between fuse EF20 and the cruise control module terminal 9.

Is the repair complete?

--

System OK

--

24
  1. Turn ON the ignition, with the engine OFF.
  2. Turn the cruise control switch ON.
  3. With the electrical connector still removed from the cruise control module, measure the voltage at terminals 7 and 2 of the connector.

Is the voltage equal to the specified value?

0 V

Go to Step 27

Go to Step 26

25

Replace the cruise control switch. Refer to Cruise Control Switch Replacement .

Is the repair complete?

--

System OK

--

26

Repair the short to voltage between the cruise control switch and the cruise control module connector.

Is the repair complete?

--

System OK

--

27
  1. Turn ON the ignition, with the engine OFF.
  2. Turn the cruise control switch ON.
  3. Select SET on the cruise control switch.
  4. While holding the switch in the SET position, measure the voltage at terminal 2 of the cruise control module connector.

Is the voltage equal to the specified value.

11-14 V

Go to Step 28

Go to Step 25

28
  1. Turn ON the ignition, with the engine OFF.
  2. Turn the cruise control switch ON.
  3. Select RESUME on the cruise control switch.
  4. While holding the switch in the RESUME position, measure the voltage at terminal 7 of the cruise control module connector.

Is the voltage equal to the specified value.

11-14 V

Go to Step 29

Go to Step 25

29
  1. Turn OFF the ignition.
  2. Disconnect the vehicle speed sensor (VSS).
  3. Use an ohmmeter to measure the resistance between the wire at the VSS and terminal 10 of the cruise control module connector.

Is the resistance equal to the specified value?

0 ohms

Go to Step 31

Go to Step 30

30

Repair the open circuit between the VSS and the cruise control module connector terminal 10.

Is the repair complete?

--

System OK

--

31

Replace the cruise control module connector.

Is the repair complete?

--

System OK

--