Circuit Description
When the Automatic Level Control (ALC) sensor detects an out of trim condition, the rear suspension leveling air compressor relay K19 energizes to provide B+ to the rear suspension leveling air compressor. The automatic level control sensor continuously monitors the controlling circuitry to determine if there is B+ present for a compress sequence or an air replenishment cycle (ARC).
Conditions for Setting the DTC
The sensor detects that the relay output is not pulled down to ground when the sensor output is active.
Action Taken When the DTC Sets
| • | The sensor flashes the LEVELING indicator lamp. |
| • | The sensor's discrete low side output drive for the relay is disabled. |
| • | The sensor continuously attempts to recover form the fault |
| • | DTC 05 is stored as a history code at the end of the ignition cycle |
Conditions for Clearing the DTC
| • | When the sensor does not detect B+ at the low side drive output of the relay when a compress sequence or an ARC is required. |
| • | Using a scan tool. |
Diagnostic Aids
Refer to the diagnostic table.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Has the Automatic Level Control (ALC) system Check been performed | -- | Go to ALC Suspension System Check . | |
Is the voltage within the specified range? | B+ | |||
3 | Locate and repair a short to B+ in circuits B25 and/or B56. If the circuits are OK, replace the rear suspension leveling air compressor relay K19. Is the repair or replacement complete? | -- | -- | |
Replace the ALC sensor. Refer to Automatic Level Control in Suspension. Is the replacement complete? | -- | -- | ||
5 |
Is the LEVELING indicator lamp flashing? | -- | System OK |
