GM Service Manual Online
For 1990-2009 cars only

Cruise Control Inoperative/Malfunctioning 3.4L

Diagnostic Aids

Important: Perform the following in order to avoid misdiagnosis.

    • Inspect for proper operation of the brake lamps.
    • Inspect for proper operation of the transmission range switch.
    • Inspect throttle linkage for mechanical binding which could cause the system to malfunction.

Step

Action

Value(s)

Yes

No

Schematic Reference: Cruise Control Schematics

1

Did you perform the Cruise Control Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Cruise Control

2

  1. Turn the ignition OFF.
  2. Disconnect the cruise control module.
  3. Turn the ignition ON, with the engine OFF.
  4. Connect a test lamp between the ignition positive voltage circuit and a good ground.

Does the test lamp illuminate?

--

Go to Step 3

Go to Step 29

3

Connect the test lamp between the ignition positive voltage circuit and the ground circuit of the cruise control module.

Does the test lamp illuminate?

--

Go to Step 4

Go to Step 30

4

  1. Make sure that the cruise control switch is OFF.
  2. Connect a test lamp between the cruise control ON switch circuit, the Set/Coast switch signal circuit, and the Resume/Accelerate switch signal circuit and a good ground one at a time.

Does the test lamp illuminate on any of the signal circuits?

--

Go to Step 13

Go to Step 5

5

  1. Turn cruise control On/Off switch On.
  2. Connect the test lamp between the cruise control on signal circuit and a good ground.

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 14

6

  1. Connect the test lamp between the cruise control set/coast signal circuit and a good ground.
  2. Press and hold the SET/COAST button.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 16

7

  1. Connect the test lamp between the cruise control resume/accel switch signal circuit and a good ground.
  2. Press and hold the RESUME/ACCEL switch.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 17

8

Connect the test lamp between the cruise control release signal circuit and a good ground.

Does the test lamp illuminate?

--

Go to Step 19

Go to Step 18

9

Connect the test lamp between the stop lamp signal circuit and a good ground.

Does the test lamp illuminate?

--

Go to Step 20

Go to Step 10

10

Press the brake pedal while monitoring the test lamp.

Does the test lamp illuminate?

--

Go to Step 11

Go to Step 21

11

Measure the voltage at the cruise control engaged signal circuit.

Does the voltage measure near the specified value?

B+

Go to Step 12

Go to Step 22

12

Check the speedometer for proper operation.

Does the speedometer operate properly?

--

Go to Step 23

Go to Speedometer and/or Odometer Inaccurate or Inoperative in Instrument Panel, Gages and Console

13

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

Did you find and correct the condition?

--

Go to Step 35

Go to Step 27

14

Test the cruise control on/off switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 15

15

Test the ignition positive voltage circuit of the cruise control on/off switch for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 27

16

Test the cruise control set/coast switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 27

17

Test the cruise control resume/accelerate switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 27

18

Test the cruise control release switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 24

19

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

Did you find and correct the condition?

--

Go to Step 35

Go to Step 9

20

Test the stop lamp switch signal circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Stop Lamps Always On in Lighting Systems

21

Test the stop lamp switch signal circuit for an open or for a high resistance between the center console fuse block and the cruise control module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Stop Lamps Inoperative in Lighting Systems

22

Test the cruise engaged signal circuit for an open, for a high resistance, or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 26

23

Test the vehicle speed signal circuit for an open or for a high resistance between the PCM and the cruise control module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 28

24

Inspect the cruise control release switch for proper adjustment. Refer to Cruise Release Switch Adjustment .

Did you find and correct the condition?

--

Go to Step 35

Go to Step 25

25

Inspect for poor connections at the harness connector of the cruise control release switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 31

26

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 32

27

Inspect for poor connections at the harness connector of the cruise control switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 33

28

Inspect for poor connections at the harness connector of the cruise control module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 35

Go to Step 34

29

Repair the ignition positive voltage circuit of the cruise control module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 35

--

30

Repair the ground circuit of the cruise control module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 35

--

31

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

Did you complete the replacement?

--

Go to Step 35

--

32

Important: Program the replacement PCM. Refer to Service Programming System (SPS) in Programming.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls.

Did you complete the replacement?

--

Go to Step 35

--

33

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 35

--

34

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

Did you complete the replacement?

--

Go to Step 35

--

35

  1. Use a scan tool in order to clear the DTC.
  2. Operate the vehicle within the conditions for cruise control operation.

Does the cruise control system operate correctly?

--

System OK

Go to Step 2