GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2006 🢒 Classic 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Speedometer and/or Odometer Inaccurate or Inoperative

Test Description

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

  1. This step tests for a malfunctioning component that is interrupting the vehicle speed signal circuit.

    2.

  2. This step tests for the proper voltage from the instrument panel cluster (IPC).

Step

Action

Value(s)

Yes

No

Schematic Reference: Instrument Cluster Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
  1. Install a scan tool.
  2. Raise the vehicles 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 Sensor parameter in the powertrain control module (PCM) Engine Data 1 list.

Does the Vehicle Speed Sensor parameter match the speedometer display?

--

Go to Step 3

Go to Step 4

3

Does the odometer operate properly?

--

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

Go to Step 12

4

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

Does the Vehicle Speed Sensor parameter match the speedometer display?

--

Go to Step 8

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the PCM connector C1.
  3. Turn ON the ignition, 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?

9.0 V

Go to Step 7

Go to Step 6

6

Test the vehicle speed signal circuit for an open, a high resistance, or 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 14

Go to Step 9

7

Test the vehicle speed 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 14

Go to Step 10

8

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 14

Go to Step 11

9

Inspect for poor connections at the harness connector of the instrument panel cluster (IPC). 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 14

Go to Step 12

10

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 14

Go to Step 13

11

Replace the cruise control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 14

--

12

Replace the IPC. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 14

--

13

Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 14

--

14

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2