For 1990-2009 cars

### Circuit Description

The exhaust valve is controlled by the Automatic Level Control (ALC) sensor. The sensor provides a low side drive whenever exhaust activity is required and during a 'head-relief' sequence, which occurs before each compressor start up. This drive output from the sensor is continually monitored to determine if the voltage level agrees with the commanded state.

### Conditions for Setting the DTC

The sensor detects that the valve output is not pulling down to ground when the sensor output is activated.

### Action Taken When the DTC Sets

• | The sensor flashes the LEVELING indicator lamp.

• | The sensor's discrete low side output drive for the valve is disabled.

• | The sensor contentiously attempts to recover from the fault.

• | DTC 07 is stored as a history code at the end of the ignition cycle.

### Conditions for Clearing the DTC

• | The DTC will clear when B+ is present at the low side output drive.

• | Using a scan tool.

### Diagnostic Aids

• | Perform the system leak test. Refer to Automatic Level Control System.

• | Refer to the diagnostic table.

### Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

1. Checks for a short to B+ in circuit M101.

2. Checks for an internal short to B+ in the exhaust valve.

#### DTC 07 Exhaust Valve Short to Battery

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Automatic Level Control (ALC) System Check performed? | -- | Go to Step 2 | Go to ALC Suspension System Check .
2 |

1. Disconnect the rear suspension leveling air compressor connector.
2. Use a DMM to measure the voltage between terminal A of the compressor connector and a known good ground.

Is the voltage reading within the specified value?

B+

Go to Step 3

Go to Step 4

3 | Locate and repair a short to B+ in circuit M101. Is the repair complete? | -- | Go to Step 7 | --
4 | Use a DMM in order to measure the resistance between terminal A and terminal C of the compressor connector. Is the resistance reading with the specified value? | 25 ohms-35 ohms | Go to Step 5 | Perform the system leak test. Go to Automatic Level Control.
5 |

1. Connect all of the connectors that were disconnected.
2. Turn the ignition switch to the ON position.
3. Clear any DTCs.
4. Wait at least 5 minutes.

Is the LEVELING indicator lamp flashing?

--

Go to Step 6

Go to Step 7

6 | Replace the ALC sensor. Refer to Automatic Level Control in Suspension. Is the replacement complete? | -- | Go to Step 7 | --
7 |

1. Connect all of the connectors that were disconnected.
2. Turn the ignition switch to the ON position.
3. Wait at least 5 minutes.

Is the rear of the vehicle level?

--

System OK

Go to Step 1