Rear of Vehicle High w/o F45
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Is any aftermarket equipment installed on the vehicle that could affect the ALC system? | -- | Go to Step 2 | Go to Step 4 |
2 | Inspect the aftermarket equipment to ensure that it is not affecting ALC performance. Is the aftermarket equipment affecting the ALC performance? | -- | Go to Step 3 | Go to Step 4 |
3 | Correct the condition. Is the condition corrected? | -- | -- | |
4 | Inspect the ELC fuse for an open fuse. Is the fuse open? | -- | Go to Step 5 | Go to Step 6 |
5 |
Important: If the fuse is open repeatedly, inspect CKT 1342 (RED) for a short to ground. Replace the fuse. Is the replacement complete? | -- | -- | |
6 | Inspect the height sensor and link for proper connection or damage. Are the height sensor and link properly connected and in good condition? | -- | Go to Step 8 | Go to Step 7 |
7 | Reconnect or replace the height sensor or link. Refer to Automatic Level Control Sensor and Bracket Replacement . Is the repair or replacement complete? | -- | -- | |
8 |
Important: The vehicle must be raised on a drive-on lift. Full vehicle weight must be on the rear tires. Important: The height sensor has a 17-27 second delay period before the exhaust solenoid is activated. Did the rear of the vehicle lower to trim level or below? | -- | Go to Step 9 | Go to Step 10 |
9 | Adjust the height sensor. Refer to Automatic Level Control Sensor Adjustment . Is trim height at the rear underbody points correct? Refer to Trim Height . | -- | Repeat Step 9 | |
10 | Move the height sensor lever up so that it is approximately 45 degrees above level (to the floor) and hold it there for a minimum of 27 seconds (17-27 seconds is the height sensor delay period). Did the air compressor come on? | -- | Go to Step 11 | |
11 | Disconnect the air tube from the air dryer. Did the rear of the vehicle lower to trim level or below? | -- | Go to Step 19 | Go to Step 12 |
12 |
Did the rear of the vehicle lower to trim level or below? | -- | Go to Step 13 | Go to Step 14 |
13 | Replace the air tube. Refer to Air Tube Replacement . Is the replacement complete? | -- | -- | |
14 | Is the vehicle uneven (more than 19 mm (0.75 in) from side to side at the rear? | -- | Go to Step 16 | Go to Step 15 |
15 | Replace both rear springs. Refer to Coil Spring Replacement . Is the trim height at the rear underbody points correct? Refer to Trim Height . | -- | -- | |
16 |
Is the vehicle still uneven more than 19 mm (0.75 in) from side to side at the rear? | -- | Go to Step 17 | Go to Step 18 |
17 | Replace the rear spring on the side of the vehicle that is high. Refer to Coil Spring Replacement . Is the trim height at the rear underbody points correct? Refer to Trim Height . | -- | Repeat this Diagnostic Table | |
18 | Replace the rear shock absorber on the side of the vehicle that is high. Refer to Shock Absorber Replacement . Is the trim height at the rear underbody points correct? Refer to Trim Height . | -- | Repeat this Diagnostic Table | |
19 |
Important: The height sensor has a 17-27 second delay period before the air compressor is activated. Is continuity present? | -- | Go to Step 21 | Go to Step 20 |
20 | Replace the air compressor head. Refer to Automatic Level Control Air Compressor Head Replacement . Is the replacement complete? | -- | -- | |
21 | Measure the voltage from the air compressor electrical connector (vehicle side), terminal C, to ground using a J 39200. Is the measurement within the specified values? | 10.5-15 V | Go to Step 23 | Go to Step 22 |
22 | Inspect for a poor connection at the rear junction block. If the connections are OK, repair the open in CKT 1342. Is the repair complete? | -- | -- | |
23 |
Important: The link must be connected. Voltage will not be present within 17-27 seconds of the ignition switch cycle (height sensor delay). Voltage will not be present after approximately seven minutes. Is the measurement within the specified values? | 10.5-15 V | Go to Step 25 | Go to Step 24 |
24 | Inspect for an open in CKT 320. Also, inspect for a poor connection at the rear junction block and at the height sensor connector. Was an open or poor connection found and repaired? | -- | ||
25 | Replace the air compressor head. Refer to Automatic Level Control Air Compressor Head Replacement . Is the replacement complete? | -- | -- |
Rear of Vehicle High w/ F45
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the ALC System Check performed? | -- | Go to Step 2 | |
2 |
Is the ALC air compressor running for more than 5 minutes? | -- | Go to Step 3 | Go to Step 6 |
3 |
Is the air compressor running? | -- | Go to Step 4 | Go to Step 5 |
4 |
Is the repair complete? | -- | Go to Step 13 | -- |
5 |
Is the replacement complete? | -- | Go to Step 13 | -- |
6 | Inspect the left and right rear position sensors for damage or disconnected links. Are any damaged sensors or disconnected links present? | -- | Go to Step 7 | Go to Step 8 |
7 | Replace the damaged rear position sensor or reconnect the link. Refer to Electronic Suspension Rear Position Sensor Replacement . Is the replacement complete? | -- | Go to Step 13 | -- |
8 |
Is air exiting the ALC intake air filter? | -- | Go to Step 11 | Go to Step 9 |
9 |
Is air exiting both of the air tubes at the ALC air dryer connection? | -- | Go to Step 10 | Go to Step 12 |
10 |
Are all of the replacements and/or installations complete? | -- | Go to Step 13 | -- |
11 |
Has the ALC Trim Height Adjustment been completed? | -- | Go to Step 13 | -- |
12 | Replace the air tube going from the air dryer to both the rear shock absorbers. Refer to Air Tube Replacement . Is the replacement complete? | -- | Go to Step 13 | -- |
13 |
Is the rear of the vehicle trim (level)? Refer to Trim Height . | -- | System OK | -- |
