GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn ignition OFF.
  2. Disconnect the Load Leveling Inflator Switch.
  3. Disconnect the Load Leveling Air Direction Valve.
  4. Connect a self-powered test lamp from terminal B to ground at the Air Inflator Switch.

Does the test light?

--

Go to Step 3

Go to Step 2

2

Locate and Repair the open BLK (1350) wire between component and ground.

Is the action complete?

--

System OK

--

3

Connect a self-powered test lamp from terminal B to ground at the Load Leveling Air Direction Valve.

Does the test light?

--

Go to Step 4

Go to Step 2

4

  1. Turn ignition ON, engine OFF.
  2. Connect a fused jumper wire from terminal A of the Load Leveling Inflator Switch to ground.

Does the Load Leveling Pump run?

--

Go to Step 5

Go to Step 6

5

Replace the Load Leveling Inflator Switch.

Is the action complete?

--

System OK

--

6

  1. Ignition ON, engine OFF.
  2. Connect a fused jumper wire from terminal E, YEL (321) to ground at the Load Leveling Timer Relay.

Does the Load Leveling Pump run?

--

Go to Step 8

Go to Step 7

7

Locate and Repair the open YEL (321) wire between the Load Leveling Timer Relay and Splice S472.

Is the action complete?

--

System OK

--

8

  1. Jumper wire still connected.
  2. Connect a test lamp from terminal A, DK BLU wire at the Load Leveling Air Direction Valve to ground.

Does the test lamp light?

--

Go to Step 12

Go to Step 9

9

  1. Jumper wire still connected.
  2. Connect a test lamp from terminal C, DK BLU wire at the Load Leveling Timer Relay to ground.

Does the test lamp light?

--

Go to Step 10

Go to Step 11

10

Locate and Repair the open DK BLU (1249) wire.

Is the action complete?

--

System OK

--

11

Replace the Load Leveling Timer Relay.

Is the action complete?

--

System OK

--

12

Using a DMM, (J39200), measure the resistance of the Load Leveling Air Direction Valve.

Is the resistance within the value indicated?

20 - 100 ohms

Go to Step 14

Go to Step 13

13

Replace the Load Leveling Air Direction Valve.

Is the action complete?

--

System OK

--

14

  1. Turn ignition OFF.
  2. Disconnect the Load Leveling Timer Relay.
  3. Connect a self-powered test lamp from terminal C Load Leveling Air Inflation Switch to ground.

Does the test lamp light?

--

Go to Step 15

Go to Step 11

15

Locate and Repair the PPL (1267) wire for a short to ground.

Is the action complete?

--

System OK

--