GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Instrument Cluster Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

Verify the fault is present.

Does the system operate normally?

--

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

Go to Step 3

3

Important: There is a flat band in the gauge where the engine temp is between 190°F and 220°F and gauge stays at 200°F.

  1. With the scan tool, select instrument panel cluster, data display, and data.
  2. Start the engine and run the engine to the operating temperature.
  3. Select the displayed coolant temp display on the scan tool.
  4. Compare the displayed Coolant Temp data on the scan tool to the temperature gauge reading on the cluster.

Are the temperatures on the scan tool and the gauge approximately the same outside the flat band?

Approximately 93°C (200°F) @ steady state

Go to Step 4

Go to Step 7

4

With the scan tool, read the Monitored Coolant Temp.

Is the Monitored Coolant Temp within the specified range ?

100-260°F (38-127°C)

Go to Step 5

Go to Step 6

5

Compare the Monitored Coolant Temp with the Displayed Coolant Temp.

Are the temperatures approximately the same?

--

Go to Step 6

Go to Step 7

6

Important: There is a flat band in the gauge where the engine temp is between 190°F and 220°F and gauge stays at 200°F.

  1. If the Monitored Coolant Temp is less than 100°F (38°C), the gauge should be at or near the lowest reading.
  2. If the Monitored Coolant Temp is greater than 260°F (127°C), the gauge should be at or near the maximum reading.

Does the gauge reading properly?

--

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

Go to Step 7

7

Replace the instrument cluster. Refer to Instrument Cluster Replacement

Did you complete the replacement?

--

Go to Step 8

--

8

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3