GM Service Manual Online
For 1990-2009 cars only

Low Engine Coolant Indicator Always On Diesel Only

Step

Action

Value(s)

Yes

No

1

Did you perform the Instrument Cluster System Check?

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Go to Step 2

Go to Instrument Cluster System Check

2

  1. Ensure the coolant level is filled above the sensor.
  2. Disconnect the connector at the Low Coolant Level Sensor.
  3. Connect a J 39200 DMM (continuity) between pins A and B.

Is continuity present?

--

Go to Step 4

Go to Step 3

3

Replace the Low Coolant Level Sensor. Refer to Surge Tank (Diesel) Replacement in Engine Cooling.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

4

Connect a J 39200 DMM (continuity) between the Low Coolant Level Sensor connector cavity B and ground.

Is continuity present?

--

Go to Step 6

Go to Step 5

5

Locate and repair the open in CKT 150 (BLK) between the Low Coolant Level Sensor and G105. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

6

  1. Disconnect the connector at the Low Coolant Level Indicator Module.
  2. Connect a J 39200 DMM (continuity) between cavity F of the Low Coolant Level Indicator Module and cavity A of the Low Coolant Level Sensor connector.

Is continuity present?

--

Go to Step 8

Go to Step 7

7

Locate and repair the open in CKT 1478 (LT GRN) between the Low Coolant Level Indicator and the Low Coolant Level Sensor. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

8

Connect a J 39200 DMM (volts) between cavity A of the Low Coolant Level Indicator Module and ground.

Is battery voltage present?

--

Go to Step 10

Go to Step 9

9

Locate and repair the open in CKT 39 (PNK) between the IP fuse Block and the Low Coolant Level Indicator Module. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

10

Connect a J 39200 DMM (continuity) between cavity C of the Low Coolant Level Indicator Module and ground.

Is continuity present?

--

Go to Step 12

Go to Step 11

11

Locate and repair the open in CKT 150 (BLK) between the Low Coolant Level Indicator Module and G200. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

12

  1. Remove the I/P Cluster.
  2. Connect a J 39200 DMM (continuity) between the cavity E of the Low Coolant Level Indicator Module and pin 25 of the I/P Cluster.

Is continuity present?

--

Go to Step 14

Go to Step 13

13

Locate and repair the open in CKT 68 (YEL/BLK) between the I/P Cluster and the Low Coolant Level Indicator Module. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

14

Connect a J 39200 DMM (continuity) between cavities 22 and 25 of the I/P Cluster.

Is continuity present?

--

Go to Step 16

Go to Step 15

15

Replace the I/P Cluster. Refer to Instrument Cluster Replacement

Is the repair complete?

--

Go to Instrument Cluster System Check

--

16

Replace the Low Coolant Level Indicator Module. Refer to Coolant Level Module Replacement in Engine Cooling.

Is the repair complete?

--

Go to Instrument Cluster System Check

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