GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2007 🢒 SKY 🢒 DTC 🢒 DTC C0186

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC C0186 00: Lateral Accelerometer Circuit Electrical Failure

DTC C0186 5A: Lateral Accelerometer Circuit Erratic

DTC C0186 3B: Lateral Accelerometer Self Test Failure

DTC C0186 1A: Lateral Accelerometer Offset Failure

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Lateral Accelerometer Supply Voltage Circuit

C0186 00

C0186 00

C0186 00

--

Lateral Accelerometer CAN Bus High Circuit

C0186 00

C0186 00

C0186 00

C0186 5A, 3B, 1A

Lateral Accelerometer CAN Bus Low Circuit

C0186 00

C0186 00

C0186 00

C0186 5A, 3B, 1A

Lateral Accelerometer Ground Circuit

--

C0186 00

--

--

Circuit/System Description

The lateral accelerometer and the yaw rate sensors are combined into one sensor external to the electronic brake control module (EBCM). The vehicle stability enhancement system (VSES) uses the lateral accelerometer input when calculating the desired yaw rate. The usable output signal is a serial data CAN circuits.

Conditions for Running the DTC

The ignition switch is in the ON position.

Conditions for Setting the DTC
    • The yaw/lateral combination sensor reports an internal failure.
    • The yaw/lateral combination sensor learns a wrong offset value.
    • Incorrectly mounted yaw/lateral sensor.

Action Taken When the DTC Sets

One or more of the following actions may occur:

    • Vehicle stability enhancement system (VSES) are disabled.
    • The VSES indicator turns ON.
    • The driver information center (DIC) displays the Service ESC message.

Conditions for Clearing the DTC
    • The condition for the DTC is no longer present.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

Possible causes of this DTC are as follows:

    • Incorrectly mounted yaw/lateral sensor
    • Internal failure in the yaw/lateral sensor
    • Intermittent wiring connections

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Antilock Brake System Connector End Views

Electrical Information Reference

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

Scan Tool Reference

Scan Tool Data List for EBCM

Circuit/System Verification

With scan tool installed, clear the DTCs then drive the vehicle in a straight line at a speed greater than 20 km/h (13 mph). If the DTC did not set as a current DTC see Diagnostic Aids.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the yaw rate/lateral accelerometer .
  2. Test for less than 6 ohm of resistance between the low reference circuit terminal 5 and ground.
    3. ⇒If greater than the specified range, test for an open/high resistance in the low reference circuit. If the circuit tests normal, replace the EBCM.
  3. Ignition ON, test for 11.8-12.2 volts between the 12-volt reference circuit terminal 3 and ground.
    4. ⇒ If less than the specified range, test the 12-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
    ⇒ If greater than the specified range, test the 12-volt reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
  4. Ignition OFF, disconnect the harness connector at the steering angle sensor.
  5. Ignition ON, test for 0 volts between the communication circuit terminal 5 and ground.
    6. ⇒If greater than the specified value, test the communication circuit for a short to voltage.
  6. Test for 0 volts between the communication circuit terminal 2 and ground.
    7. ⇒If greater than the specified value, test the communication circuit for a short to voltage.
  7. Ignition OFF, test for infinite resistance between the communication circuit terminal 5 and ground.
    8. ⇒If not the specified value, test the communication circuit for a short to ground.
  8. Test for infinite resistance between the communication circuit terminal 2 and ground.
    9. ⇒If not the specified value, test the communication circuit for a short to ground.
  9. Test for less than 1 ohm of resistance between the yaw rate sensor circuit terminals 1 and steering wheel sensor terminal 5.
    10. ⇒If greater than the specified range, test the communication circuit for an open/high resistance.
  10. Test for less than 1 ohm of resistance between the yaw rate sensor circuit terminal 2 and steering wheel sensor terminal 2.
    11. ⇒If greater than the specified range, test the communication circuit for an open/high resistance.
  11. Test for infinite resistance between the communication circuit 5 and the communication circuit 2.
    12. ⇒If not the specified value, test the communication circuits for a short together.
  12. If all circuits test normal, replace the yaw rate/lateral sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Steering Angle Sensor Centering
    •  Diagnostic Test Drive
    •  Control Module References for EBCM replacement, setup, and programming