GM Service Manual Online
For 1990-2009 cars only

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

DTC C0186 1A: Lateral Accelerometer Circuit Bias Level Out of Range

DTC C0186 3B: Lateral Accelerometer Circuit Internal Self Test Failed

DTC C0186 5A: Lateral Accelerometer Circuit Plausibility Failure

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Ignition Voltage

C0186 00, C0196 00

C0186 00, C0196 00

C0186 00, C0196 00

C0186 1A, 3B, 5A, C0196 1A, 3B, 5A

CAN Bus High Signal

U2142 00, (U2143 00 HP7)

U2142 00, (U2143 00 HP7)

U2142 00, (U2143 00 HP7)

U2142 00, (U2143 00 HP7)

CAN Bus Low Signal

U2142 00, (U2143 00 HP7)

U2142 00, (U2143 00 HP7)

U2142 00, U2143 00 HP7)

U2142 00, (U2143 00 HP7)

Ground

--

C0186 00, C0196 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

Ignition ON.

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

    • The EBCM disables the VSES for the duration of the ignition cycle.
    • A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

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

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the yaw rate/lateral accelerometer sensor.
  2. Test for less than 5 ohms 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.
  4. Ignition ON, verify a test lamp illuminates between the ignition circuit terminal 3 and ground.
  5. If the test lamp does not illuminate, test the ignition circuit for a short to ground or open/high resistance.
  6. If all circuits test normal, replace the yaw rate/lateral sensor. If the DTC resets, replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Vehicle Yaw Sensor Replacement
    •  Control Module References for EBCM replacement, setup and programming