Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Automatic Level Control Schematics | |||
1 | Did you review the Automatic Level Control (ALC) Description and Operation? | Go to Step 2 | |
2 |
Important: The vehicle must be raised on a drive on hoist.
| Go to Step 3 | Go to Step 4 |
3 | Repair or replace any damaged or leaking components. Is the repair complete? | Go to Step 27 | -- |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 17 |
5 | Connect a test lamp between the position sensor harness connector battery positive voltage terminal and position sensor ground terminal. Does the test lamp illuminate? | Go to Step 6 | Go to Step 18 |
6 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 19 |
7 | Using a 3 amp fused jumper wire, jumper the position sensor harness connector compressor motor control circuit to a good ground. Does the ALC compressor engage? | Go to Step 15 | Go to Step 8 |
8 | Did the ALC relay click? | Go to Step 9 | Go to Step 11 |
9 |
Does the test lamp illuminate? | Go to Step 10 | Go to Step 13 |
10 | Connect a test lamp between the compressor motor harness connector compressor feed circuit and the compressor ground circuit. Does the test lamp illuminate? | Go to Step 23 | Go to Step 20 |
11 | Test the ALC relay coil side feed circuit for a open circuit or a short to ground. Did you find and correct the condition? | Go to Step 27 | Go to Step 12 |
12 | Test the ALC compressor motor control circuit for an open circuit or a short to voltage. Did you find and correct the condition? | Go to Step 27 | Go to Step 21 |
13 | Test the ALC compressor motor feed circuit for a open circuit or a short to ground. Did you find and correct the condition? | Go to Step 27 | Go to Step 14 |
14 | Test the ALC relay supply circuit for an open circuit or a short to ground. Did you find and correct the condition? | Go to Step 27 | Go to Step 21 |
15 | Check the ALC position sensor adjustment. Refer to Automatic Level Control Sensor Adjustment . Is the adjustment OK? | Go to Step 22 | Go to Step 16 |
16 | Readjust the ALC position sensor. Refer to Automatic Level Control Sensor Adjustment . Did you complete the adjustment? | Go to Step 27 | -- |
17 | Repair open circuit or short to ground on position sensor battery positive circuit. Did you complete the repair? | Go to Step 27 | -- |
18 | Repair open circuit or short to voltage on the position sensor ground circuit. Did you complete the repair? | Go to Step 27 | -- |
19 | Repair open circuit or short to ground on the position sensor ignition positive voltage circuit. Did you complete the repair? | Go to Step 27 | -- |
20 | Repair open circuit or short to voltage on the ALC compressor ground circuit. Did you find and correct the condition? | Go to Step 27 | -- |
21 | Inspect for poor connections/terminal tension at the ALC relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 27 | Go to Step 24 |
22 | Inspect for poor connections/terminal tension at the ALC Position Sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 27 | Go to Step 25 |
23 | Inspect for poor connections/terminal tension at the ALC Compressor Assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 27 | Go to Step 26 |
24 | Replace the ALC relay. Did you complete the replacement? | Go to Step 27 | -- |
25 | Replace the ALC Position Sensor. Refer to Automatic Level Control Sensor and Bracket Replacement . Did you complete the replacement? | Go to Step 27 | -- |
26 | Replace the ALC Compressor. Refer to Automatic Level Control Air Compressor Head Replacement . Did you complete the replacement? | Go to Step 27 | -- |
27 | Operate the vehicle within the conditions for enabling the automatic level control. Does the ALC operate correctly? | System OK | Go to Step 2 |
