GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

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

1

Did you perform the Engine Cooling Diagnostic System Check?

Go to Step 2

Go to Cooling System Description and Operation

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 in Wiring Systems

Go to Step 3

3

  1. Disconnect the coolant level switch.
  2. Turn the ignition switch to RUN.
  3. 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 indicator turn OFF?

Go to Step 4

Go to Step 5

4

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

Did you complete the replacement?

Go to Step 9

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5

  1. Reconnect the coolant level switch.
  2. Disconnect the low engine coolant level indicator module connector.

Did the low coolant indicator turn OFF?

Go to Step 6

Go to Step 8

6

Replace the low coolant indicator module.

Did you complete the repair?

Go to Step 9

Go to Step 7

7

Repair the short to ground in the low coolant switch signal circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and complete the repair?

Go to Step 9

--

8

Repair the short to ground in the low coolant level indicator control circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and complete the repair?

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