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 sensor's 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:
| • | An open in the 5 volt reference circuit of the air pressure sensor. |
| • | A short to ground in the 5 volt reference circuit of the air pressure sensor. |
| • | An open in the signal circuit of the air pressure sensor. |
| • | A short to ground in the signal circuit of the air pressure sensor. |
| • | An open in the low reference circuit of the air pressure sensor. |
| • | 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.
-
Tests for a high resistance or an open in the ground circuit.
-
Check for open or high resistance in the sensor ground circuit.
-
The replacement suspension control module must be calibrated.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: | ||||
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 | Go to |
Does the scan tool indicate that the Air Pressure Sensor parameter is within the specified range? | 0.15 -- 4.85 V | Go to in Wiring Systems. | Go to Step 3 | |
3 |
Does the scan tool indicate that the air pressure sensor data parameter is at the specified value? | 0.0 V | Go to Step 4 | Go to Step 6 |
4 | Connect a 3 amp fused jumper wire between the 5 volt reference and signal circuit of the ALC compressor harness connector. Does the scan tool indicate that the Air Pressure Sensor data parameter is within the specified range? | 4.8-5.2 V | Go to Step 9 | Go to Step 5 |
5 | Test the pressure sensor signal circuit for an open, or short to ground. Refer to and in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 6 |
6 | Test the pressure sensor signal circuit for a short to voltage. Refer to and in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 7 |
Test the pressure sensor 5 volt reference circuit an open, or short to ground. Refer to and in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 8 | |
8 | Test the pressure sensor 5 volt reference circuit for a short to voltage. Refer to and in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 10 |
9 | Test the pressure sensor low reference circuit for an open, or short to voltage. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 |
10 | Inspect for poor connections at the ALC compressor harness connector. Refer to and in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 |
11 | Inspect for poor connections at the suspension control module harness connector. Refer to and in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 13 | |
12 | Replace the pressure sensor. Refer to in Automatic Level Control. Did you complete the replacement? | Go to Step 14 | -- | |
|
Important: After replacement, use the scan tool to perform the calibration procedure for the suspension control module, located under Special Functions: Recalibration. Replace the suspension control module. Refer to in Electronic Suspension Control (ESC). Did you complete the replacement? | -- | Go to Step 14 | -- | |
14 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
