For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the ALC System Check? | -- | Go to Step 2 | Go to Automatic Level Control System Operation Check
2 | Test the ELC Fuse for an open. Did you find the condition? | -- | Go to Step 3 | Go to Step 4
3 | Repair the short to ground in CKT 1240. Did you complete the repair? | -- | Go to Automatic Level Control System Operation Check | --
4 |

1. Disconnect the auto level control air compressor connector.
2. Connect a voltmeter to terminals A, C and E to ground.

Is the voltage within the specified range?

9-14 V

Go to Step 5

Go to Step 14

5 | Measure voltage from the auto level control air A, C and E to terminal G. Is the measured voltage within the specified range? | 9-14 V | Go to Step 7 | Go to Step 6
6 | Repair the poor connection or open in CKT 1240 between S445 and the auto level control air inflator relay harness connector terminal D. Did you complete the repair? | -- | Go to Automatic Level Control System Operation Check | --
7 | Measure voltage between the auto level control air inflator relay terminal D and H. Is the measured voltage within the specified range? | 9-14 V | Go to Step 9 | Go to Step 8
8 | Repair the poor connection or open in CKT 1725 between the auto level control air inflator relay harness connector terminal H and G401. Did you complete the repair? | -- | Go to Automatic Level Control System Operation Check | --
9 |

1. Reconnect the aut--o level control air inflator relay harness connector.
2. Disconnect the air inflator switch.
3. Connect a 10 A fused jumper between the air inflator switch harness connector terminal A and terminal B.

Is the auto level control air compressor ON?

--

Go to Step 10

Go to Step 11

10 | Replace the air inflator switch. Refer to:

• | Automatic Level Control Inflator Air Switch Replacement for long wheel base with HVAC

• | Automatic Level Control Inflator Air Switch Replacement for long wheel base without HVAC

• | Automatic Level Control Inflator Air Switch Replacement for short wheel base

Did you complete the repair?

--

Go to Automatic Level Control System Operation Check

--

11 | Replace the auto level control air inflator relay. Refer to:

• | Automatic Level Control Relay Replacement for long wheel base with HVAC

• | Automatic Level Control Relay Replacement for long wheel base without HVAC

• | Automatic Level Control Relay Replacement for short wheel base

Did you complete the repair?

--

Go to Automatic Level Control System Operation Check

--

12 |

1. With a 10 A fused jumper still connected, disconnect the auto level control air compressor.
2. Using a DMM, measure for voltage between B+ and the auto level control air compressor harness connector terminal D.

Is the measured voltage within the specified range?

9-14 V

Go to Step 13

Go to Step 14

13 | Repair a poor connection or open in CKT 240, between the fuse block terminal H4 and S445. Did you complete the repair? | -- | Go to Automatic Level Control System Operation Check | --
14 | Measure for voltage between the auto level control air compressor harness connector terminal A and ground. Is the measured voltage within the specified range? | 9-14 V | Go to Step 16 | Go to Step 15
15 | Repair a poor connection or open in CKT 1240, between the ELC fuse and the auto level control air compressor harness connector terminal A, terminal C, and terminal E. Did you complete the repair? | -- | Go to Automatic Level Control System Operation Check | -
16 | Measure for voltage between the auto level control air compressor harness connector terminal E and ground. Is the measured voltage within the specified range? | 9-14 V | Go to Step 17 | Go to Step 15
17 |

1. Disconnect the auto level control air compressor relay.
2. Connect a 10 A fused jumper to the auto level control air compressor relay from terminal 1 to terminal 4.

Is the auto level control air compressor ON?

--

Go to Step 18

Go to Step 19

18 | Replace the auto level control air compressor relay. Refer to Air Compressor Replacement . Did you complete the repair? | -- | Go to Automatic Level Control System Operation Check | --
19 | Measure for voltage between the auto level control air compressor harness connector terminal A and terminal G. Is the measured voltage within the specified range? | 9-14 V | Go to Step 21 | Go to Step 20
20 | Repair the poor connection or open in CKT 1725, between the auto level control air compressor harness connector terminal G and G401. Did you complete the repair? | -- | Go to Automatic Level Control System Operation Check | --
21 | Replace the auto level control air compressor. Refer to Air Compressor Replacement . Did you complete the repair? | -- | System OK | --