GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Turn the ignition switch to the RUN position.

Does the Service Engine Soon indicator come on?

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Go to Step 2

Go to Instrument Cluster Indicators and Gauges Inoperative

2

  1. Disconnect the engine coolant level indicator module connector.
  2. Turn the ignition switch to the RUN position.
  3. Connect a (3 amp) fused jumper between the engine coolant level indicator module connector terminal B and ground.

Is the LOW COOLANT warning indicator on?

--

Go to Step 3

Go to Step 6

3

Connect a (3 amp) fused jumper between the engine coolant level indicator module connector terminals B and C.

Is the LOW COOLANT warning indicator on?

--

Go to Step 4

Go to Step 5

4

  1. Check for a poor connection at the engine coolant level indicator module connector.
  2. If OK, replace the engine coolant level indicator module. Refer to Coolant Level Module Replacement in Engine Cooling.

Has the repair been made and the system rechecked?

--

System OK

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5

Repair a poor connection or open in CKT 451 between the engine coolant level indicator module harness connector terminal C and G113.

Has the repair been made and the system rechecked?

--

System OK

--

6

Check for a poor connection or open in CKT 68.

Is there a poor connection or open in CKT 68?

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Go to Step 7

Go to Step 8

7

Repair poor connection or open in CKT 68.

Has the repair been made and the system rechecked?

--

System OK

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8

  1. Check the low coolant warning indicator bulb and bulb connections.
  2. If OK, replace the instrument cluster. Refer to Instrument Cluster Replacement .

Has the repair been made and the system rechecked?

--

System OK

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