GM Service Manual Online
For 1990-2009 cars only

Test Description

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

  1. This step makes sure that none of the DTCs listed are present which would affect cruise control operation.

  2. This step places the cruise control module in a functional test mode to allow testing of the; Cruise control switch circuit, brake switch circuit, the vehicle speed sensor (VSS) circuit, PNP switch circuit, if equipped, and the cruise release switch circuit, if equipped.

  3. This step checks the vehicle speed circuit (VSS).

Step

Action

Value(s)

Yes

No

Schematic Reference: Cruise Control Schematics

Connector End View Reference: Cruise Control Connector End Views

DEFINITION: This table diagnoses the cruise control function is totally inoperative. It does not diagnose the lamp(s) only are inoperative.

1

Did you review the Cruise Control Description and Operation and perform the necessary inspections?

--

Go to Step 2

Go to Symptoms - Cruise Control

2

  1. Drive the vehicle above 40 km/h (25 mph).
  2. Press and release the CRUISE ON OFF button.
  3. Accelerate to the desired speed.
  4. Move the cruise control switch downward to the SET/COAST position and release.
  5. Take your foot off the accelerator pedal.

Does the cruise control system operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Verify that the following OBD2 DTCs are not present:

    • P0505
    • P0758
    • P0120
    • P0500
    • P1780

Are any of the DTCs listed stored in memory?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 4

4

  1. Turn the ignition switch to LOCK.
  2. Wait 5 seconds.
  3. Turn ON the ignition, with the engine OFF.
  4. If the vehicle has an automatic transaxle, Move the gear shift lever to the drive (D) position.
  5. Move the cruise control switch downward to the SET/COAST position and hold.
  6. Press the CRUISE ON-OFF switch and release.

Does the CRUISE indicator lamp flash twice, pause, and then repeat this sequence?

--

Go to Step 5

Go to Step 18

5

Release the cruise control switch from the SET/COAST position.

Does the CRUISE indicator lamp light continuously?

--

Go to Step 8

Go to Step 6

6

Operation or malfunction of any of the following controls will extinguish the cruise indicator lamp when in diagnostic mode:

    • Gear shift lever not in the drive (D) position
    • Brake pedal pressed
    • Clutch pedal pressed
    • Cruise control switch is held in the CANCEL position.

Are the controls in their normal position?

--

Go to Step 7

--

7

Test the following control circuits for a short condition:

    • The brake switch
    • The cruise control switch

Test the following control circuits for an open condition:

    • The PNP switch
    • The cruise release switch

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 30

Go to Step 24

8

Move the cruise control switch upward to the RES/ACC position and hold .

Does the CRUISE indicator lamp flash 3 times, pause, and then repeat this sequence?

--

Go to Step 9

Go to Step 18

9

Pull and release the cruise control switch to the CANCEL position while observing the CRUISE control indicator.

Is the CRUISE indicator lamp OFF when the cruise control switch is pulled to the CANCEL position, and ON when the cruise control switch is released?

--

Go to Step 10

Go to Step 18

10

Press and release the brake pedal while observing the CRUISE indicator lamp.

Is the CRUISE indicator lamp OFF with the brake pedal is pressed, and ON with the brake pedal released?

--

Go to Step 11

Go to Step 19

11

Does the vehicle have an automatic transaxle?

--

Go to Step 12

Go to Step 13

12

Move the automatic transaxle control lever to neutral (N), then to drive (D) while observing the CRUISE indicator lamp.

Is the CRUISE indicator lamp ON with the manual selector in drive (D), and OFF in neutral (N)?

--

Go to Step 14

Go to Step 20

13

Press the clutch pedal while observing the CRUISE indicator lamp.

Is the CRUISE indicator lamp OFF when the clutch pedal is pressed and ON when the clutch pedal is released?

--

Go to Step 14

Go to Step 21

14

  1. Turn ignition switch to LOCK.
  2. Wait 5 seconds.
  3. Start the vehicle.
  4. If the vehicle has an automatic transaxle, Move the gear shift lever to the drive (D) position.
  5. Move the cruise control switch downward to the SET/COAST position and hold.
  6. Press the CRUISE ON-OFF switch and release.
  7. The CRUISE indicator lamp will flash twice, pause, and then repeat this sequence
  8. Release the cruise control switch from the SET/COAST position
  9. Accelerate driving wheels to 40 km/h (25 mph) while observing the CRUISE indicator lamp.

Does the CRUISE indicator lamp flash rapidly?

--

Go to Step 15

Go to Step 22

15

Is vehicle equipped with a 4-speed automatic transaxle?

--

Go to Step 16

Go to Step 17

16

  1. Start engine.
  2. Set the overdrive (OD) switch to the ON position
  3. Accelerate vehicle to 80 km/h (50 mph).
  4. press the cruise control switch to the CRUISE ON-OFF position and set speed to engage cruise control.
  5. Make sure transaxle is in 4th gear (OD).
  6. Press and hold the parking brake release button while pulling up the parking brake gradually (to induce load drag) up to the moment that the transaxle downshifts into 3rd gear.
  7. Immediately release the parking brake and notice a 2 second delay before the transaxle upshifts from 3rd gear into OD.

Did the transaxle delay OD upshift?

--

Go to Step 17

Go to Step 23

17

  1. Turn OFF the ignition.
  2. Disconnect the cruise control module (CCM) connector and connector C2 of the PCM.
  3. Test the idle signal circuit between cavity 13 of the CCM connector and cavity 16 of C2 of the PCM connector for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 30

Go to Step 22

18

Important:: The cruise control switch is part of the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement in SIR.

To disable the SIR system refer to SIR Disabling and Enabling in SIR.

  1. Disconnect the cruise control switch.
  2. Measure the resistance between terminal 2 and terminal 3 of the cruise control switch with the switch in all 3 positions.

Did the measurements equal the specified values?

    • Cruise ON-OFF 0.0 - 1.0 ohms
    • RES/ACC 210 - 270 ohms
    • SET/COAST  560 - 700 ohms
    • CANCEL 1389 - 1700 ohms

Go to Step 24

Go to Step 25

19

  1. Disconnect the cruise control module connector.
  2. Connect a test lamp between cavity 3 of the cruise control module and ground.
  3. Depress and release the brake pedal while observing the test lamp.

Did the test lamp illuminate when the brake pedal was depressed?

--

Go to Step 24

Go to Step 26

20

  1. Disconnect the cruise control module connector.
  2. Connect a test lamp between cavity 4 of the cruise control module and ground.
  3. Place the PNP switch in the D position.

Did the test lamp illuminate when the PNP switch is in the D position?

--

Go to Step 24

Go to Step 27

21

  1. Disconnect the cruise control module connector.
  2. Connect a test lamp between cavity 3 of the cruise control module and ground.

Does the test lamp extinguish when the clutch pedal is depressed and illuminate when the pedal is released?

--

Go to Step 24

Go to Step 27

22

  1. Disconnect the cruise control module connector.
  2. Test the vehicle speed input circuit between the left instrument panel junction block C3 cavity 7 and cavity 12 of the cruise control module connector for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 30

Go to Step 24

23

  1. Disconnect the cruise control module connector.
  2. Disconnect Connector C1 of the PCM.
  3. Test the O/D cut control circuit between C1 cavity 18 of the PCM connector and cavity 6 of the cruise control module connector for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 30

Go to Step 24

24

Inspect for poor connections at the harness connector of the cruise control module. 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 30

Go to Step 28

25

Inspect for poor connections at the harness connector of the cruise control 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 30

Go to Step 29

26

Repair the open in the stoplamp switch circuit. Refer to Cruise Control Release Switch Replacement and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 30

--

27

Repair the open in the cruise release signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 30

--

28

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

Did you complete the replacement?

--

Go to Step 30

--

29

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

Did you complete the replacement?

--

Go to Step 30

--

30

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3