GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Check the vehicle for Diagnostic Trouble Codes (DTC).

Are any DTCs present?

--

Go to Diagnostic Trouble Code Identification in Automatic Transaxle

Go to Step 2

2

  1. Install a scan tool.
  2. Raise the vehicle's drive wheels. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Start the engine.
  4. Place the transmission into drive.
  5. With the scan tool, observe the Vehicle Speed parameter.

Does the Vehicle Speed parameter match the speedometer display?

--

Go to Step 3

Go to Step 4

3

Does the odometer operate properly?

--

System OK

Go to Step 19

4

  1. Turn OFF the ignition.
  2. Disconnect the cruise control module.
  3. Start the engine.
  4. Place the transmission into drive.
  5. With the scan tool, observe the Vehicle Speed parameter.

Does the Vehicle Speed parameter match the speedometer display?

--

Go to Step 12

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the body control module.
  3. Start the engine.
  4. Place the transmission into drive.
  5. With the scan tool, observe the Vehicle Speed parameter.

Does the Vehicle Speed parameter match the speedometer display?

--

Go to Step 13

Go to Step 6

6

  1. Turn OFF the ignition.
  2. Disconnect the rear side door actuator control module.
  3. Start the engine.
  4. Place the transmission into drive.
  5. With the scan tool, observe the Vehicle Speed parameter.

Does the Vehicle Speed parameter match the speedometer display?

--

Go to Step 14

Go to Step 7

7

  1. Turn OFF the ignition.
  2. Disconnect the driver information center.
  3. Start the engine.
  4. Place the transmission into drive.
  5. With the scan tool, observe the Vehicle Speed parameter.

Does the Vehicle Speed parameter match the speedometer display?

 

Go to Step 15

Go to Step 8

8

  1. Turn OFF the ignition.
  2. Disconnect the radio.
  3. Start the engine.
  4. Place the transmission into drive.
  5. With the scan tool, observe the Vehicle Speed parameter.

Does the Vehicle Speed parameter match the speedometer display?

--

Go to Step 16

Go to Step 9

9

  1. Turn the ignition OFF.
  2. Disconnect the PCM connector C1.
  3. Turn the ignition ON, with the engine OFF.
  4. Measure the voltage from the vehicle speed signal circuit to a good ground.

Does the voltage measure greater than the specified value?

9 V

Go to Step 11

Go to Step 10

10

Test the vehicle speed signal circuit for an open, for a high resistance, or for a short to ground between the IPC and the PCM. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 17

11

Test the vehicle speed signal circuit for a short to voltage between the IPC and the PCM. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 18

12

Inpect for poor connections at the harness connector of the cruise control module. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 21

13

Inpect for poor connections at the harness connector of the body control module. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 22

14

Inpect for poor connections at the harness connector of the rear side door actuator control module. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 23

15

Inpect for poor connections at the harness connector of the driver information center. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 24

16

Inpect for poor connections at the harness connector of the radio. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 25

17

Inpect for poor connections at the harness connector of the instrument panel cluster (IPC). Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

9 - 10 V

Go to Step 26

Go to Step 19

18

Inpect for poor connections at the harness connector of the powertrain control module. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 20

19

Replace the instrument cluster. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

--

Go to Step 26

--

20

Important: Program the replacement PCM.

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

Did you complete the replacement?

--

Go to Step 26

--

21

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

Did you complete the replacement?

--

Go to Step 26

--

22

Replace the body control module. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

--

Go to Step 26

--

23

Replace the rear side door actuator control module. Refer to Rear Side Door Actuator Control Module Replacement in Doors.

Did you complete the replacement?

--

Go to Step 26

--

24

Replace the driver information display. Refer to Driver Information Center Replacement .

Did you complete the replacement?

--

Go to Step 26

--

25

Replace the radio. Refer to Radio Replacement in Entertainment.

Did you complete the replacement?

--

Go to Step 26

--

26

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2