GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Important:  Speedometer accuracy tolerance on this vehicle is +/- 10 percent

1

Inspect fuse F12.

Is fuse F12 open?

--

Go to Step 2

Go to Step 3

2

  1. Inspect for a short circuit and repair it, if necessary.
  2. Replace fuse F12.

Is the repair complete?

--

System OK

--

3

  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage at fuse F12.

Is the voltage within the specified range?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the power supply for the ignition 2 relay.

Is the repair complete?

--

System OK

--

5

  1. Connect a scan tool.
  2. Check for diagnostic trouble codes (DTCs).

Is DTC 24, P0502, P0720, P0721, or P0722 set?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 6

6

  1. Remove the instrument cluster.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage at instrument cluster connector terminal B14.

Is the voltage within the specified range?

11-14 V

Go to Step 8

Go to Step 7

7

Repair the open circuit between Fuse F12 and the instrument cluster.

Is the repair complete?

--

System OK

--

8

Use an ohmmeter to Measure the resistance between ground and instrument cluster connector terminal C5.

Is the resistance near the specified value?

0 ohms

Go to Step 10

Go to Step 9

9

Repair the open circuit between ground and instrument cluster connector terminal C5.

Is the repair complete?

--

System OK

--

10

Use an ohmmeter to measure the continuity of the circuit wire between the vehicle speed sensor terminal B and instrument cluster connector terminal C7.

Is the continuity near the specified value?

0 ohms

Go to Step 12

Go to Step 11

11

Repair the open circuit between the vehicle speed sensor and the instrument cluster.

Is the repair complete?

--

System OK

--

12

Replace the instrument cluster. Refer to Instrument Cluster Replacement .

Is the repair complete?

--

System OK

--