GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Connect a test lamp from CKT 36 (LT GRN) at the Radiator Shutter Engine Coolant Temperature Sensor in terminal A to a chassis ground.
  2. Turn the ignition switch ON.

Did the test lamp light?

--

Go to Step 2

Go to Step 3

2

  1. Remove the Radiator Shutter Engine Coolant Temperature Sensor Connector.
  2. Connect a test lamp from CKT 36 (LT GRN) to CKT 150 (BLK) in terminal B at the Radiator Shutter Engine Coolant Temperature Sensor harness connector.

Did the test lamp light?

--

Go to Step 10

Go to Step 11

3

Connect a test lamp from CKT 36 (LT GRN) at the Radiator Shutter Control Valve to a chassis ground.

Did the test lamp light?

--

Go to Step 12

Go to Step 4

4

Connect a test lamp from CKT 639 (PNK) at the Radiator Shutter Control Valve to a chassis ground.

Did the test lamp light?

--

Go to Step 13

Go to Step 5

5

Connect a test lamp from CKT 639 (PNK) at the Ignition Relay to a chassis ground.

Did the test lamp light?

--

Go to Step 14

Go to Step 6

6

Connect a test lamp from CKT 40 (ORN) at the Ignition Relay to a chassis ground.

Did the test lamp light?

--

Go to Step 8

Go to Step 7

7

Connect a test lamp from CKT 40 (ORN) at the IP Fuse Block to a chassis ground.

Did the test lamp light?

--

Go to Step 8

Go to Step 15

8

Connect a test lamp from CKT 39 (PNK) at the Ignition Relay terminal A1 to a chassis ground.

Did the test lamp light?

--

Go to Step 9

Go to Step 16

9

Connect a test lamp from CKT 39 (PNK) to CKT 150 (BLK) at the Ignition Relay.

Did the test lamp light?

--

Go to Step 17

Go to Step 11

10

Replace the Radiator Shutter Engine Coolant Temperature Sensor. Refer to Engine Coolant Temperature Sensor Replacement or Engine Coolant Temperature Sensor Replacement .

Is the repair complete?

--

System OK

--

11

Locate and repair the open in CKT 150 (BLK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

System OK

--

12

Locate and repair the open in CKT 36 (LT GRN). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

System OK

--

13

Replace the Radiator Shutter Control Valve. Refer to Shutter Valve Replacement .

Is the repair complete?

--

System OK

--

14

Locate and repair the open in CKT 639 (PNK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

System OK

--

15

Locate and repair the open in CKT 442 (RED). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

System OK

--

16

Locate and repair the open in CKT 39 (PNK). Refer to Wiring Repairs in Wiring Systems. Repair the open.

Is the repair complete?

--

System OK

--

17

Replace the Ignition Relay.

Is the repair complete?

--

System OK

--