GM Service Manual Online
For 1990-2009 cars only

Low Engine Coolant Indicator Always On Domestic

Step

Action

Value(s)

Yes

No

1

Was the Instrument Cluster System Check performed?

--

Go to Step 2

Go to Instrument Cluster System Check

2

  1. Place the ignition switch in the RUN position.
  2. Disconnect the connector at the low engine coolant level indicator sensor.
  3. Connect a J 39200 between the low engine coolant level indicator sensor connector, cavity F for CKT 1478 (LT GRN) and ground.

Is continuity present?

--

Go to Step 4

Go to Step 3

3

Repair the open in CKT 151 (BLK/WHT) between the low engine coolant level indicator sensor and ground G109.

Is the low engine coolant indicator lamp always illuminated?

--

Go to Step 4

Go to Instrument Cluster System Check

4

Connect an unpowered test lamp between the low engine coolant level indicator sensor, cavity A for CKT 1478 (LT GRN), and ground.

Does the test lamp light?

--

Go to Step 5

Go to Step 6

5

Replace the low engine coolant level indicator sensor.

Is the low engine coolant indicator lamp always illuminated?

--

Go to Step 6

Go to Instrument Cluster System Check

6

  1. Disconnect the connector at the engine coolant level indicator module.
  2. Connect a fused jumper wire between B+ and the engine coolant level indicator module connector, cavity F for CKT 1478 (LT GRN).
  3. Connect an unpowered test lamp between the low engine coolant indicator sensor connector, cavity A for CKT 1478 (LT GRN), and ground.

Does the test lamp light?

--

Go to Step 7

Go to Step 8

7

Replace the low engine coolant level indicator module.

Is the low engine coolant indicator lamp always illuminated?

--

--

Go to Instrument Cluster System Check

8

Repair the open in CKT 1478 (LT GRN) between the instrument cluster and the low engine coolant lever indicator sensor.

Is the low engine coolant indicator lamp always illuminated?

--

--

Go to Instrument Cluster System Check

Low Engine Coolant Indicator Always On Export

Step

Action

Value(s)

Yes

No

1

Was the Instrument Cluster System Check performed?

--

Go to Step 2

Go to Instrument Cluster System Check

2

  1. Turn the ignition switch to the RUN position.
  2. Disconnect the connector at the low engine coolant level indicator sensor.
  3. Connect a self-powered lamp between the following components:
  4. • The low engine coolant level indicator sensor connector cavity B for the CKT 151 (BLK/WHT) wire
    • Ground

Does the test lamp light?

--

Go to Step 3

Go to Step 4

3

Connect an unpowered test lamp between following components:

    • The low engine coolant level indicator sensor cavity A for the CKT 1478 (LT GRN) wire
    • Ground

Did the test lamp light?

--

Go to Step 5

Go to Step 6

4

  1. Locate the open in the CKT 151 (BLK/WHT) wire between the following components:
  2. • The low engine coolant level indicator sensor
    • Ground G109
  3. Repair the open in the CKT 151 (BLK/WHT) wire between the following components:
  4. • The low engine coolant level indicator sensor
    • Ground G109

Is the repair complete?

--

Go to Instrument Cluster System Check

--

5

Replace the low engine coolant level indicator sensor.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

6

  1. Disconnect the connector at the engine coolant level indicator module.
  2. Connect a fused jumper wire between the following components:
  3. • B+
    • The engine coolant level indicator module connector cavity F for the CKT 1478 (LT GRN) wire
  4. Connect an unpowered test lamp between the following components:
  5. • The low engine coolant level indicator sensor connector cavity A for the CKT 1478 (LT GRN) wire
    • Ground

Did the test lamp light?

--

Go to Step 7

Go to Step 8

7

Replace the engine coolant level indicator module.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

8

  1. Locate the open in the CKT 1478 (LT GRN) wire between the following components:
  2. • The instrument cluster
    • The low engine coolant level indicator sensor
  3. Repair the open in the CKT 1478 (LT GRN) wire between the following components:
  4. • The instrument cluster
    • The low engine coolant level indicator sensor

Is the repair complete?

--

Go to Instrument Cluster System Check

--