GM Service Manual Online
For 1990-2009 cars only

Coolant Temperature Gauge Inoperative

Step

Action

Value(s)

Yes

No

1

Were you sent here from the IPC Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, attempt to establish communications with the PCM.

Does the scan tool communicate with the PCM?

--

Go to Step 3

Go to Powertrain On Board Diagnostic (OBD) System Check

3

Select PCM display DTC function on the scan tool.

Does the scan tool display DTC P0117, P0118, P1114, or P1115?

--

Go to Powertrain On Board Diagnostic (OBD) System Check

Go to Step 4

4

With a scan tool, select IPC special functions and command a sweep test (minimum to maximum) on the engine coolant temperature gauge.

Does the scan tool control the engine coolant temperature gauge?

--

Go to Step 5

Go to Step 8

5

With a scan tool, observe Engine Coolant Temperature parameter in the IPC data list.

Does the scan tool indicate the correct Engine Coolant Temperature?

--

Go to Step 6

Go to Step 7

6

With a scan tool, observe the Engine Coolant Temperature parameter in the IPC data list and the coolant temperature gauge display on the IPC.

Does the scan tool display correspond with the coolant temperature gauge display within the specified value?

15°C

(15°F)

System OK

Go to Step 8

7

With a scan tool, observe Engine Coolant Temperature (ECT) parameter in the PCM data list.

Does the scan tool indicate the correct Engine Coolant Temperature?

--

Go to Step 8

Go to Powertrain On Board Diagnostic (OBD) System Check

8

Replace the IPC assembly. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

--

Go to Step 9

--

9

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2