GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 DTS 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 DTC C0615, C0620, C0625, or C0630

DTC Descriptor

DTC C0615 08: Left Front Position Sensor Circuit - Signal Invalid

DTC C0615 55: Left Front Position Sensor Circuit - Expected Number Of Transitions Not Reached

DTC C0620 08: Right Front Position Sensor Circuit - Signal Invalid

DTC C0620 55: Right Front Position Sensor Circuit - Expected Number Of Transitions Not Reached

DTC C0625 08: Left Rear Position Sensor Circuit - Signal Invalid

DTC C0625 55: Left Rear Position Sensor Circuit - Expected Number Of Transitions Not Reached

DTC C0630 08: Right Rear Position Sensor Circuit - Signal Invalid

DTC C0630 55: Right Rear Position Sensor Circuit - Expected Number Of Transitions Not Reached

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit/System Description

The electronic suspension control (ESC) module supplies a 5-volt reference signal to the suspension position sensor. The suspension position sensor supplies an analog voltage (0.35-4.75 volts) back to the ESC module which represents the position between the body and the wheel. The sensor is also grounded through the ESC module.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC
    • The DTC is set when the ESC module measures the position sensor signal voltage below 0.35 volt or above 4.75 volts for more than 1 second while the vehicle is operated under normal driving conditions.
    • The fault is detected during 3 consecutive ignition cycles, or during the same ignition cycle after clearing the DTC with a scan tool.

Action Taken When the DTC Sets
    • The ESC will enter the speed dependent damping mode.
    • Both left and right normal force outputs will be set to the default output states.
    • The ESC sends a message to the instrument panel cluster (IPC) to display SERVICE SUSPENSION SYSTEM message.

Conditions for Clearing the DTC

A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.

Diagnostic Aids

Before proceeding with the diagnostics, ensure the electrical harness connector at the suspect damper or sensor is fully engaged by pushing the harness connector toward the damper or sensor. If an audible click is heard, or substantial engagement travel is noted, ensure the remaining damper and sensor connectors are fully engaged as well.

Reference Information

Schematic Reference

Suspension Controls Schematics

Connector End View Reference

Suspension Controls Connector End Views

Description and Operation

Electronic Suspension Control Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Output Controls
    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification

Ignition ON, observe the scan tool Position Sensor Data parameter. The reading should be between 0.35-4.75 volts.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the applicable suspension position sensor.
  2. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit terminal C and ground.
    3. ⇒If greater than the specified range, test the low reference circuit for an open/high resistance. If circuit tests normal, replace the ESC module.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A and ground.
    4. ⇒If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ESC module.
    ⇒ If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ESC module.
  4. Verify the scan tool position sensor parameter is less than 0.35 volts.
    5. ⇒If greater than the specified range, test the signal circuit terminal B for a short to voltage. If all circuits test normal replace the ESC module.
  5. Install a 3-A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal A. Verify the scan tool position sensor parameter is greater than 4.75 volts.
    6. ⇒If less that the specified range, test the signal circuit for a short to ground or an open high resistance. If all circuits test normal replace the ESC module.
  6. If all circuits test normal, replace the applicable suspension position sensor.

Component Testing
  1. Install a 3-A fused jumper wire between the 5-volt reference terminal A and 5 volts. Install a jumper wire between the low reference terminal C and ground.
  2. Sweep the suspension position sensor through the entire range while monitoring the voltage between the signal terminal and the low reference terminal. The range should vary between 0.35-4.75 volts without any spikes or dropouts.
    3. ⇒If not within the specified range or is erratic, replace the applicable suspension position sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Electronic Suspension Front Position Sensor Replacement
    •  Electronic Suspension Rear Position Sensor Replacement
    •  Control Module References for ESC replacement, setup, and programming.