GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Radiator Shutter Schematics

DEFINITION: The low coolant indicator lamp is ON, without a low engine coolant level condition.

1

Did you review the system operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Engine Cooling

2

  1. Check that the engine coolant level is full.
  2. Turn the ignition switch to RUN.

Does the low coolant indicator come on for bulb check, then go out?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Turn the ignition switch OFF.
  2. Disconnect the coolant level switch.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a fused jumper wire between the coolant level switch signal circuit and the ground circuit of the coolant level switch connector.

Does the low coolant level indicator turn OFF?

Go to Step 8

Go to Step 4

4

Test the ground circuit of the low coolant level switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 5

5

Test the low coolant level switch signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 6

6

  1. Turn OFF the ignition.
  2. Disconnect the multifunction alarm module (MFAM)
  3. Turn ON the ignition, with the engine OFF.

Does the low coolant indicator turn OFF?

Go to Step 9

Go to Step 7

7

Test the coolant indicator control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 10

8

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 .

Did you find and correct the condition?

Go to Step 14

Go to Step 11

9

Inspect for poor connections at the harness connector of the multifunction alarm module (MFAM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 12

10

Inspect for poor connections at the harness connector of the instrument panel cluster (IPC). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 13

11

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

Did you complete the replacement?

Go to Step 14

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12

Replace the multifunction alarm module (MFAM). Refer to Multifunction Alarm Module Replacement .

Did you complete the replacement?

Go to Step 14

--

13

Replace the instrument panel cluster. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

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 2