Step | Action | Value(s) | Yes | No | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
DEFINITION: The rear of the vehicle will not raise, is always low, or leaks down when the vehicle is not used. | ||||||||||||||
1 | Is any aftermarket equipment installed on the vehicle that could affect the ALC system? | -- | Go to Step 2 | Go to Step 4 | ||||||||||
2 | Check 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 | Check the ELC fuse in the RH MaxiFuse® Block and the ABS/CCR fuse in the IP Fuse Block for an open (blown) condition. Is the fuse open? | -- | Go to Step 5 | Go to Step 6 | ||||||||||
5 | Replace the fuse. NOTE: If the fuse is open (blown) repeatedly, check CKT 641 (BRN) or CKT 1042 (RED) for a short circuit to ground condition. Is the replacement complete? | -- | -- | |||||||||||
6 | Check the height sensor and link for proper connection and damage. Are the height sensor and the link properly connected and in good condition? | -- | Go to Step 8 | Go to Step 7 | ||||||||||
7 | Reconnect or replace the height sensor or the link. Refer to Automatic Level Control Sensor and Bracket Replacement . Is the repair or replacement complete? | -- | -- | |||||||||||
8 | Does the vehicle leak down when the vehicle is not used for an extended period of time (overnight), but then come up to normal trim height with vehicle use? | -- | Go to Step 28 | Go to Step 9 | ||||||||||
9 |
Important: Allow 27 seconds for the air compressor to start and then additional time for the struts to inflate. Does the rear of the vehicle rise and not leak down? | -- | Go to Step 10 | Go to Step 12 | ||||||||||
10 | Measure the rear trim height. Refer to Trim Height in Suspension General Diagnosis. Is the trim height at the rear underbody points correct? | -- | Go to Step 11 | |||||||||||
11 | Adjust the height sensor. Refer to Automatic Level Control Sensor Adjustment . Is the adjustment complete? | -- | -- | |||||||||||
12 | Did the air compressor operate when weight was added? | -- | Go to Step 28 | Go to Step 13 | ||||||||||
13 |
Is the air compressor operating? | -- | Go to Step 14 | |||||||||||
14 |
Is the measurement within the specified value? | 10.5--15 V | Go to Step 16 | Go to Step 15 | ||||||||||
15 | Repair the open circuit condition in circuit 641 (BRN). Is the replacement or repair complete? | -- | -- | |||||||||||
16 | Measure the voltage from the terminal where relay pin 30 was removed to ground (this terminal is hot at all times). Is the measurement within the specified value? | 10.5--15 V | Go to Step 18 | Go to Step 17 | ||||||||||
17 | Repair the open circuit condition in circuit 1042 (RED) between the RH MaxiFuse® block and the IP junction block. Is the repair complete? | -- | -- | |||||||||||
18 |
Important: The ignition switch must be cycled if the ignition was left on from the previous step. Allow 27 seconds for the air compressor to cycle. Is the measurement within the specified value? | 10.5--15 V | Go to Step 20 | Go to Step 19 | ||||||||||
19 | Check for a poor connection at the height sensor connector, terminal B, or an open-circuit condition in circuit 321. Was a poor connection or open-circuit condition found and corrected? | -- | ||||||||||||
20 | Connect a 30-amp fused jumper between the terminals where relay pins 30 and 87 were removed. Is the air compressor operating? | -- | Go to Step 21 | Go to Step 22 | ||||||||||
21 | Replace the ELC relay. Is the replacement complete? | -- | -- | |||||||||||
22 |
Is the measurement within the specified value? | 10.5--15 V | Go to Step 24 | Go to Step 23 | ||||||||||
23 | Repair the open-circuit condition in circuit 322 . Is the repair complete? | -- | -- | |||||||||||
24 |
Is the measurement within the specified value? | 10.5--15 V | Go to Step 26 | Go to Step 25 | ||||||||||
25 | Repair the open-circuit condition in CKT 1250 (BLK). Is the repair complete? | -- | -- | |||||||||||
26 |
Is the air compressor operating? | -- | Go to Step 13 | Go to Step 27 | ||||||||||
27 | Replace the air compressor. Refer to Air Compressor Replacement . Is the replacement complete? | -- | -- | |||||||||||
28 | Check the following:
Was a leak or damage found and corrected? | -- | Go to Step 29 | |||||||||||
29 |
Is the air compressor able to reach it 690 kPa (100 psi)? | 690 kPa (100 psi) | Go to Step 31 | Go to Step 30 | ||||||||||
30 | Replace the air compressor. Refer to Air Compressor Replacement . Is the replacement complete? | -- | -- | |||||||||||
31 | Does the air pressure reading on the J 22124-B stay at 690 kPa (100 psi)? | 690 kPa (100 psi) | Go to Step 32 | Go to Air Compressor Leak Test | ||||||||||
32 | One of the following components is leaking:
Replace the component with the leak. Is the replacement complete? |