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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 Escalade ESV 🢒 Suspension 🢒 Automatic Level Control 🢒 DTC C0711

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.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0711 Level Control Air Pressure Sensor Circuit

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC
    • The air pressure sensor 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.
    • The 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.

  1. This step tests for a high resistance or an open in the ground circuit.

  2. This step checks for a open or high resistance in the sensor ground circuit.

  3. The replacement suspension control module must be calibrated.

Step

Action

Value(s)

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 Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, observe the Air Pressure Sensor data parameter in the ALC data list.

Does the scan tool indicate that the Air Pressure Sensor parameter is within the specified range?

0.15-4.85 V

Go to Diagnostic Aids

Go to Step 3

3
  1. Turn OFF the ignition.
  2. Disconnect the automatic level control (ALC) compressor connector.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the air pressure sensor data parameter.

Does the scan tool indicate that the air pressure sensor data parameter is at the specified value?

4.8-5.2 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 Circuit Testing and Testing for Short to Ground 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 Circuit Testing and Testing for a Short to Voltage in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 7

7

Test the pressure sensor 5-volt reference circuit an open or short to ground. Refer to Circuit Testing and Testing for Short to Ground 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 Circuit Testing and Testing for a Short to Voltage 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 Circuit Testing and Testing for Intermittent Conditions and Poor Connections 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 Circuit Testing and Testing for Intermittent Conditions and Poor Connections 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 Automatic Level Control Air Dryer and Pressure Sensor Replacement .

Did you complete the replacement?

--

Go to Step 14

--

13

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 Electronic Suspension Control Module Replacement in Electronic Suspension Control (ESC).

Did you complete the replacement?

--

Go to Step 14

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14
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK