GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Ensure the Air Inflator Switch is the OFF position.
  2. Turn ignition OFF
  3. Disconnect the Load Leveling Pump connector.
  4. Turn ignition ON, engine OFF.
  5. Connect a test lamp from terminal E, ORN (1840) to ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 2

2

Locate and Repair an open in the ORN (1840) wire between the Load Leveling Pump and the UBEC.

Is the action complete?

--

System OK

--

3

Connect a test lamp from terminal A, PNK (639) to ground.

Does the test lamp light?

--

Go to Step 5

Go to Step 4

4

Locate and Repair an open in the PNK (639) wire between the Load Leveling Pump and the BBEC.

Is the action complete?

--

System OK

--

5

Connect a self-powered test lamp from terminal G, BLK (1350) to ground.

Does the test lamp light?

--

Go to Step 7

Go to Step 6

6

Locate and Repair an open in the BLK (1350) wire between Load Leveling Pump and ground.

Is the action complete?

--

System OK

--

7

  1. Turn ignition OFF.
  2. Reconnect the Load Leveling Pump.
  3. Disconnect the Load level Height Sensor.
  4. Turn ignition ON, engine OFF.
  5. Connect a test lamp from terminal D, PNK (639) to ground.

Does the test lamp light?

--

Go to Step 9

Go to Step 8

8

Locate and Repair an open in the PNK (639) wire between the Load level Height Sensor and Splice S473.

Is the action complete?

--

System OK

--

9

Connect a self-powered test lamp from terminal A, BLK (1350) to ground.

Does the test lamp light?

--

Go to Step 11

Go to Step 10

10

Locate and Repair an open in the BLK (1350) wire between the Load level Height Sensor and Splice S471.

Is the action complete?

--

System OK

--

11

Connect a test lamp from terminal C, LT BLU (1298) to ground.

Does the test lamp light?

--

Go to Step 12

Go to Step 15

12

Connect a fused jumper wire from terminal B, YEL (321) to ground.

Does the pump start and run?

--

Go to Step 13

Go to Step 14

13

Replace the Load level Height Sensor.

Is the action complete?

--

System OK

--

14

Replace the Load Leveling Pump.

Is the action complete?

--

System OK

--

15

  1. Gain access to the Load Leveling Timer Relay.
  2. Connect a test lamp (back probe) from terminal B, LT BLU (1298) at the Load Leveling Timer Relay to ground.

Does the test lamp light?

--

Go to Step 16

Go to Step 17

16

Locate and Repair the open in the LT BLU (1298) wire between the Load Leveling Timer Relay and the Load level Height Sensor.

Is the action complete?

--

System OK

--

17

Connect a test lamp (back probe) from terminal D, ORN (1840) at the Load Leveling Timer Relay to ground.

Does the test lamp light?

--

Go to Step 19

Go to Step 18

18

Locate and repair the open in the ORN (1840) wire between Load Leveling Timer Relay and UBEC

Is the action complete?

--

System OK

--

19

Replace the Load Leveling Timer Relay.

Is the action complete?

--

System OK

--