GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 XLR 🢒 Accessories 🢒 Navigation Systems 🢒 DTC C0615, C0620, C0625, or C0630

Circuit Description

The electronic suspension control (ESC) module supplies 5 volts to the position sensors. The position sensors use the supplied 5 volts to produce an analog output range of 0-5 volts. The ESC module calculates vehicle suspension settings based upon the voltage levels received back from the position sensors. The ESC model monitors for an out of range condition.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC C0615 Left Front Position Sensor Circuit
    • DTC C0620 Right Front Position Sensor Circuit
    • DTC C0625 Left Rear Position Sensor Circuit
    • DTC C0630 Right Rear Position Sensor Circuit

DTC Symptom

DTC Symptom Descriptor

08

Signal Invalid

55

Expected Number of Transitions/Events not Reached

Conditions for Running the DTC
    • The ignition is ON.
    • The ESC function is enabled.

Conditions for Setting the DTC
    • The ESC module senses position sensor output voltage under 0.35 or over 4.75 volts.
    • The condition must be detected for 1 second in 4 consecutive ignition cycles.
    • No activity on the position sensor when activity detected on 2 or more other position sensors.

Action Taken When the DTC Sets
    • Stores a DTC C0615, C0620, C0625, or C0630 in the ESC memory.
    • Command speed dependent damping system default AND command normal force signals to default state.
    • Sends a message to the instrument panel cluster (IPC) to display the SERVICE SUSPENSION SYSTEM message.

Conditions for Clearing the DTC
    • The ESC module senses the correct position sensor output voltage between 0.35-4.75 volts.
    • A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • Use the IPC clearing DTC feature.
    • Using a scan tool

Diagnostic Aids
    • The following conditions may cause an intermittent malfunction to occur:
       - There is an intermittent open or short in the position sensor circuit.
       - Bent, disconnected, or damaged position sensor linkage.
    • When using a scan tool in order to read position sensor voltage, always make sure the vehicle is sitting with the full vehicle weight on its wheels. Measuring position sensor voltage with the vehicle raised and the wheels hanging may lead to incorrect diagnosis.
    • An intermittent DTC C0615, C0620, C0625 or C0630 may produce a random firm/soft ride condition.
    • The ESC module uses an ignition cycle counter diagnosis approach to set this DTC. This requires the ESC module to detect a malfunction 4 times before setting the DTC. To disable this feature, use a scan tool to clear all DTCs before performing diagnosis procedures.
    • If the DTC is a history DTC, the problem may be intermittent. Using a scan tool, monitor the position sensor voltage while test driving the vehicle or moving the wiring and connectors. This can often cause the malfunction to occur.

If the left front position sensor DTC symptom was 08 then allow 30 seconds for redetection following clear codes.

If the left front position sensor DTC symptom was 55 then redetection requires driving the vehicle.

Test Description

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

  1. This step tests the position sensor signal voltage range using a scan tool. Normal signal voltage is between 1.5-3.5 volts.

    2.

  2. This step tests the position sensor signal voltage range using a scan tool with the sensor disconnected. Normal signal voltage range with the sensor disconnected is approximately 0 volts.

    3.

  3. This step tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.

    4.

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

    5.

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

    6.

  6. This step tests for an open or high resistance in the position sensor ground circuit.

Step

Action

Values

Yes

No

Schematic Reference: Suspension Controls Schematics

Connector End View Reference: Suspension Controls Connector End Views

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 the scan tool, observe the Position Sensor Data parameter in the electronic suspension control (ESC) data list.

Does the scan tool indicate that the Position Sensor Data parameter is within the specified range?

1.5-3.5 V

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the position sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Position Sensor data parameter.

Does the scan tool indicate that the Position Sensor data parameter is less than the specified value?

0.35 V

Go to Step 4

Go to Step 10

4

  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the position sensor and the signal circuit of the position sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Position Sensor Data parameter.

Does the scan tool indicate the Position Sensor Data parameter is greater than the specified value?

4.75 V

Go to Step 5

Go to Step 8

5

  1. Disconnect the fused jumper wire.
  2. Measure the voltage between the 5-volt reference circuit of the position sensor and the ground circuit of the position sensor.

Does the voltage measure less than the specified value?

5 V

Go to Step 6

Go to Step 7

6

  1. Turn OFF the ignition.
  2. Measure the resistance from the ground circuit of the position sensor to a good ground.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 12

Go to Step 11

7

Test the 5-volt reference 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 16

Go to Step 13

8

Test the 5-volt reference circuit of the position sensor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 9

9

Test the signal circuit of the position sensor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

10

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 16

Go to Step 13

11

  1. Disconnect the ESC module.
  2. Test the ground circuit of the position sensor for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

12

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

Did you find and correct the condition?

--

Go to Step 16

Go to Step 14

13

Inspect for poor connections at the harness connector of the ESC module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 15

14

Replace the applicable position sensor. Refer to Electronic Suspension Front Position Sensor Replacement or Electronic Suspension Rear Position Sensor Replacement .

Did you complete the replacement?

--

Go to Step 16

--

15

Replace the ESC module. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 16

--

16
  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