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Home >> Chevrolet >> 2004 >> Optra Base, Standard >> Repair and Diagnosis >> Accessories & Equipment >> Cruise Control Systems >> Diagnostic Information and Procedures >> Cruise Control Inoperative/Malfunctioning >> Test Description

Test Description

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

  1. 5:  The electromagnetic clutch in the cruise control actuator 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 actuator.
  • The actuator 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 - 2.0L 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 F11 and F13.
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. Inspect the voltage at fuses F11 and F13.
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 actuator.
  2. Turn ON the ignition, with the engine OFF.
  3. Inspect the voltage at terminal H of the cruise control actuator 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 F11 and cruise control actuator, connector terminal H.
Is the repair complete?		 - System OK -
14 With the electrical connector still removed from the cruise control actuator, use an ohmmeter to measure the resistance between cruise control actuator connector terminal E and ground.
Is the resistance equal to the specified value?		 0 Ω Go to Step 16  Go to Step 15 
15 Repair the open circuit between ground and terminal E of the cruise control actuator connector.
Is the repair complete?		 - System OK -
16 With the electrical connector still removed from the cruise control actuator, use an ohmmeter to measure the resistance between connector terminal C and the stop lamp switch terminal 4.
Is the resistance equal to the specified value?		 0 Ω Go to Step 18  Go to Step 17 
17 Repair the open circuit between the cruise control actuator connector terminal C and the stop lamp 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 actuator, use an voltmeter to inspect the voltage at terminal C of the cruise control actuator 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 fuse EF13 and terminal C of the cruise control actuator 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 actuator, use a voltmeter to measure the voltage at terminal B 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 actuator connector terminal B.
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 actuator, use a voltmeter to measure the voltage at terminal B 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 EF21 and the cruise control actuator terminal B.
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 actuator, measure the voltage at terminals G and D 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 actuator 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 G of the cruise control actuator 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 D of the cruise control actuator 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. Disconnect the transmission control module (TCM) connector B, if equipped with the ZF 4HP 16 automatic transmission.
  4. Use an ohmmeter to measure the resistance as follows:
    • Between the wire at the VSS and terminal A of the cruise control actuator connector, if equipped with the Aisin 81-40LE automatic transmission or the D-20 manual transmission.
    • Between the TCM connector B terminal B1 and the VSS, and then measure the resistance between the TCM connector B terminal B8 and the cruise control module connector terminal A, if equipped with the ZF 4HP 16 automatic transmission.
Is the resistance equal to the specified value?		 0 Ω Go to Step 31  Go to Step 30 
30 Repair the open circuit as follows:
  • Between the VSS and the cruise control actuator connector terminal A, if equipped with the Aisin 81-40LE automatic transmission or the D-20 manual transmission.
  • Between the VSS and the TCM connector B terminal B1 or between the TCM connector B terminal B8 and the cruise control actuator connector terminal A, if equipped with the ZF 4HP 16 automatic transmission.

Is the repair complete?		 - System OK -
31 Replace the cruise control actuator.
Is the repair complete?		 - System OK -
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