GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Engine Cooling Schematics

Connector End View Reference: Cooling System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Turn ON the ignition, with the engine OFF.

Does the low coolant indicator illuminate?

Go to Step 3

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

3

Disconnect the coolant level switch.

Does the low coolant indicator turn OFF?

Go to Step 7

Go to Step 4

4

With a scan tool, observe the body control module (BCM) data parameter in the BCM.

Does the scan tool indicate that the Low Coolant Level parameter is Low?

Go to Step 9

Go to Step 5

5

With the scan tool, observe the instrument panel cluster (IPC) data parameter in the BCM.

Does the scan tool indicate that the low coolant lamp is ON?

Go to Step 10

Go to Step 6

6

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

Did you complete the repair?

Go to Step 12

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7

Inspect for poor connections at the harness connector of the coolant level switch. 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 12

Go to Step 8

8

Replace the coolant level switch. Refer to Radiator Surge Tank Replacement .

Did you complete the repair?

Go to Step 12

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9

Test the low coolant level indicator control circuit of the coolant level switch for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

10

Inspect for poor connections at the harness connector of the BCM. 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 12

Go to Step 11

11

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

Did you complete the repair?

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2