GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 DTS 🢒 Suspension 🢒 Air Suspension 🢒 DTC C0625 or C0630

Circuit Description

The left and right rear air suspension position sensor provides a signal voltage between 0.5-4.85 volts to the air suspension control module. This signal voltage represents the wheel's position relative to the body. The air suspension control module provides a 5-volt reference and a low reference to the sensor.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC C0625 Left Rear Position Sensor Circuit
    • DTC C0630 Right Rear Position Sensor Circuit

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description .

DTC Symptom

DTC Symptom Descriptor

08

Signal Invalid

55

Expected Number of Transition Not Reached

Conditions for Running the DTC

At power-up and continuous when ignition is activated

Conditions for Setting the DTC

The air suspension control module senses a suspension sensor voltage below 0.5 volt or above 4.85 volts.

Action Taken When the DTC Sets
    • Air suspension functionality is suspended.
    • SERVICE SUSPENSION message is displayed.

Conditions for Clearing the DTC

The DTC will clear when the condition for setting the DTC is removed.

Diagnostic Aids

This DTC is set for a high or low signal to the air suspension control module from the air suspension sensor.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step checks the air suspension sensor data parameter.

    2.

  2. This step tests for the proper operation of the circuit in the high voltage range.

    3.

  3. This step tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens upon performing this test, the signal circuit has a short to voltage.

    4.

  4. This step tests for a short to ground in the 5-volt reference circuit.

    5.

  5. This step tests the 5-volt reference circuit for the air suspension sensor.

Step

Action

Values

Yes

No

Schematic Reference: Suspension Controls Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the suspension position sensor 5 volt reference parameter in the data list for the air suspension control module.

Is the position sensor parameter within the specified range?

0.5-4.85 V

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the air suspension sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the suspension position sensor 5 volt reference parameter.

Is the position sensor parameter more than the specified value?

0.5 V

Go to Step 4

Go to Step 8

4

  1. Turn OFF the ignition
  2. Connect a 3-amp fused jumper wire between the signal circuit of the air suspension sensor and the low reference circuit of the air suspension sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the position sensor parameter.

Is the position sensor parameter less than the specified value?

0.5 V

Go to Step 5

Go to Step 9

5

  1. Turn OFF the ignition.
  2. Disconnect the fused jumper wire.
  3. Turn ON the ignition, with the engine OFF.
  4. Test the 5-volt reference circuit voltage of the suspension position sensor.

Is the suspension position sensor 5-volt reference voltage greater than the specified value?

4.85 V

Go to Step 7

Go to Step 6

6

Test the 5-volt reference circuit of the suspension position sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

7

Test the 5-volt reference circuit of the suspension position sensor for one of the following conditions:

    • A short to voltage
    • A high resistance
    • An open
        Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 11

8

Test the signal circuit of the position sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

9

Test the signal circuit of the position sensor for one of the following conditions:

    • A short to voltage
    • A high resistance
    • An open
        Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 10

10

Test the low reference circuit of the position sensor for one of the following conditions:

    • A high resistance
    • An open
        Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

11

Inspect for poor connections at the harness connector of the position sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 13

12

Inspect for poor connections at the harness connector of the air suspension control module. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13

Replace the air suspension position sensor. Refer to Air Spring Leveling Sensor Replacement .

Did you complete the replacement?

--

Go to Step 15

--

14
  1. Replace the air suspension control module. Refer to Air Suspension Control Module Replacement .
  2. Perform the suspension position calibration procedure for the air suspension module if necessary after checking the trim height procedure. Refer to Suspension Position Calibration .

Did you complete the replacement?

--

Go to Step 15

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15
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

--

Go to Step 2

System OK