GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Connector End View Reference: Engine Cooling Schematics

1

Did you perform the Engine Cooling Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Engine Cooling

2

  1. Verify that the engine coolant is at the proper level.
  2. Turn ON the ignition, with the engine OFF.

Does the instrument panel cluster (IPC) display Low Engine Coolant?

Go to Step 3

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

3

  1. Install a scan tool.
  2. With a scan tool, view the Coolant Level Switch data in the Engine Data 2 data list.

Does the scan tool display Low?

Go to Step 4

Go to Step 7

4

  1. Disconnect the coolant level sensor electrical connector.
  2. Connect a 3-amp fused jumper between the coolant level switch signal circuit of the coolant level sensor electrical connector and the ground circuit of the coolant level sensor electrical connector.
  3. With a scan tool, view the Coolant Level Switch data in the Engine Data 2 data list.

Does the scan tool display OK?

Go to Step 8

Go to Step 5

5

  1. Connect a 3-amp fused jumper between the coolant level switch signal circuit of the coolant level sensor electrical connector and a good ground.
  2. With a scan tool, view the Coolant Level Switch data in the Engine Data 2 data list.

Does the scan tool display OK?

Go to Step 10

Go to Step 6

6

Inspect the coolant level signal circuit for an open or short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 9

7

Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 11

8

Inspect for poor connections at the harness connector of the coolant level sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 12

9

Inspect for poor connections at the harness connector of the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 13

10

Repair the open in the ground circuit of the coolant level sensor. Refer to Wiring Repairs in Wiring Systems.

Did you Complete the repair?

Go to Step 14

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11

Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Did you Complete the repair?

Go to Step 14

--

12

Replace the surge tank. Refer to Radiator Surge Tank Replacement .

Did you Complete the repair?

Go to Step 14

--

13

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

Did you Complete the repair?

Go to Step 14

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14

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3