Circuit Description
The suspension control module uses a 5 volt analog air pressure sensor to determine the amount of air pressure in the Automatic Level Control (ALC ) system. The valid signal voltage range of the sensor is 0.15-4.85 volts. The sensor signal voltage will increase and decrease within the valid voltage range as system pressure increases and decreases.
Conditions for Running the DTC
The Ignition is On.
Conditions for Setting the DTC
| • | The air pressure sensors signal voltage is out of the valid range. |
| • | A short to ground, short to voltage, or an open in the pressure sensor, or the circuits to the sensor. |
Action Taken When the DTC Sets
| • | DTC C0711 is stored in memory. |
| • | ALC system pressure is set to a default value. |
| • | The ALC system is disabled. |
Conditions for Clearing the DTC
| • | A current DTC will clear when the malfunction is no longer present. |
| • | A history DTC will clear after 100 malfunction free ignition cycles. |
| • | Using a scan tool. |
Diagnostic Aids
If DTC C0870 is present, perform the diagnosis for that DTC first.
The following conditions may cause a malfunction to occur:
| • | A malfunction in the air pressure sensor |
| • | A leak in the air tube at the air pressure sensor may cause a faulty sensor voltage reading |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Automatic Level Control Schematics | ||||
1 |
Important: If DTC C0870 is present, perform the diagnosis for DTC C0870 first. Did you perform the Automatic Level Control Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate that the Air Pressure Sensor parameter is within the specified range? | 0.15 -- 4.85 V | Go to Step 8 | Go to Step 3 |
3 | With the 3-amp fused jumper wire still connected, does the scan tool indicate that Air Pressure Sensor parameter is below the specified voltage value? | 4.5 V | Go to Step 4 | Go to Step 5 |
4 | Test the pressure sensor signal circuit for an open, or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 6 |
5 | Test the pressure sensor signal circuit for a short to voltage. Refer to Testing for a Short to Voltage and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 7 |
6 | Test the pressure sensor 5 volt reference circuit an open, or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9 |
7 | Test the pressure sensor 5 volt reference circuit for a short to voltage. Refer to Testing for a Short to Voltage and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9 |
8 | Test the pressure sensor low reference circuit for an open, or short to voltage. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 |
9 | Inspect for poor connections at the ALC compressor harness connector. 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 13 | Go to Step 10 |
10 | Inspect for poor connections at the suspension control module harness connector. 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 13 | Go to Step 12 | |
11 | Replace the pressure sensor. Refer to Automatic Level Control Air Dryer and Pressure Sensor Replacement in Automatic Level Control. Did you complete the replacement? | Go to Step 13 | -- | |
|
Important: After replacement, the suspension control module must be programmed. Refer to Service Programming System (SPS) in Programming and Setup. Replace the suspension control module. Refer to Electronic Suspension Control Module Replacement in Electronic Suspension Control (ESC). Did you complete the replacement? | -- | Go to Step 13 | -- | |
13 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
