DTC C0186 Without JL7
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 Descriptor
DTC C0186 00: Lateral Accelerometer CircuitDTC C0186 08: Lateral Accelerometer Rate Signal Invalid
DTC C0186 09: Lateral Accelerometer Rate of Change Above Threshold
DTC C0186 75: Lateral Accelerometer Circuit Bias Level Out Of Range
DTC C0186 3B: Lateral Accelerometer Internal Self Test Failed
DTC C0186 1A: Lateral Accelerometer Circuit Bias Level Out Of Range
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Lateral Accelerometer 5-volt Reference Circuit | C0186 00 | C0186 00 | C0186 00 | -- |
Lateral Accelerometer Signal Circuit | C0186 00 | C0186 00 | C0186 00 | C0186 08, C0186 09, C0186 1A, C0186 52 |
Lateral Accelerometer Low Reference Circuit | -- | C0186 00 | -- | -- |
Circuit/System Description
The electronic brake control module (EBCM) uses the lateral accelerometer signal to determine the lateral forces acting on a vehicle during a turn or a skid. The EBCM uses the signal from the lateral accelerometer as one of the inputs to operate the vehicle stability enhancement system (VSES).
Conditions for Running the DTC
C0186 00, 09, and 1A
| • | The ignition is ON. |
| • | Ignition voltage is greater than 8 volts. |
C0186 08
| • | Ignition voltage is ON. |
| • | Ignition voltage is greater than 8 volts. |
| • | The vehicle speed is greater than 0 km/h (0 mph). |
C0186 19
| • | Ignition voltage is ON. |
| • | Ignition voltage is greater than 8 volts. |
| • | The vehicle is stationary. |
C0186 52
| • | Ignition voltage is ON. |
| • | Ignition voltage is greater than 8 volts. |
| • | DTC C0196 is not set. |
| • | The yaw rate is less than 8 degrees per second. |
Conditions for Setting the DTC
C0186 00, 09, and 1A
One of the following conditions exist:
| • | The lateral accelerometer signal voltage is less than 0.15 volt. |
| • | The lateral accelerometer signal voltage is greater than 4.85 volts for 0.03 second. |
C0186 08
The lateral accelerometer signal voltage increases less than 0.5 volt during the lateral accelerometer sensor self test.
C0186 09
The lateral accelerometer signal exceeds 11 g (0.39 oz) per second twice within 0.2 second.
C0186 19
The lateral acceleration is greater than 0.5 g (0.02 oz) for 1 second.
C0186 1A
Both of the following conditions exist:
| • | The compensated bias value of the lateral accelerometer sensor is greater than 0.3 g (0.01 oz). |
| • | The yaw rate is centered. |
C0186 52
The slip rate error exceeds 0.5 g (0.02 oz) 60 times within one drive cycle.
Action Taken When the DTC Sets
If equipped, the following actions will occur:
| • | The EBCM disables the VSES for the duration of the ignition cycle. |
| • | The driver information center (DIC) displays the SERVICE STABILITY SYS message. |
| • | The antilock brake system (ABS) and the traction control system (TCS) remain functional. |
Conditions for Clearing the DTC
| • | The condition for setting the DTC is no longer present. |
| • | The EBCM automatically clears a history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
The lateral accelerometer is packaged with the yaw rate sensor as a single component.
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the yaw and lateral acceleration sensor.
- Test for less than 5 ohms between the low reference circuit terminal D and ground.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal B and ground.
- Verify the scan tool Lateral Accelerometer Signal parameter is less than 0 volts.
- Install a 3A fused jumper wire between the signal circuit terminal E and the 5-volt reference circuit terminal B. Verify the scan tool Lateral Accelerometer Signal is greater than 4.8 volts.
- If all circuits test normal, test or replace the yaw and lateral acceleration sensor.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM. |
| ⇒ | 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 EBCM. |
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM. |
| ⇒ | If greater than the specified range, test the signal circuit terminal E for a short to voltage. If the circuit tests normal, replace the EBCM. |
| ⇒ | If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the EBCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM replacement, setup, and programming |
DTC C0186 With JL7
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 09: Lateral Accelerometer Circuit Rate of Change Above ThresholdDTC C0186 1A: Lateral Accelerometer Circuit Bias Level Out Of Range
DTC C0186 3B: Lateral Accelerometer Circuit Erratic Internal Self Test Failed
DTC C0186 75: Lateral Accelerometer Circuit Signal Above Allowable Range
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Lateral Accelerometer Supply Voltage Circuit | -- | -- | -- | -- |
Lateral Accelerometer Communication Circuit | -- | -- | -- | C0186 09, 3B, 1A, 75, |
Lateral Accelerometer Communication Circuit | -- | -- | -- | C0186 09, 3B, 1A, 75 |
Lateral Accelerometer Communication Ground Circuit | -- | -- | -- | -- |
Circuit/System Description
The lateral accelerometer and the yaw rate sensors are combined into one sensor. The sensors communicate through the serial data network to the Vehicle Stability Control Module along with other control modules to perform stability control. The vehicle stability enhancement system (with JL7) uses the lateral accelerometer input when calculating the desired yaw rate.
Conditions for Running the DTC
The ignition switch is in the ON position.
DTC C0561 71 is not set as a result of a lateral acceleration sensor circuit or internal fault during the current ignition cycle.
Conditions for Setting the DTC
C0186 09
The lateral accelerometer combination changes by more than 550 meters/second per second.
C0186 3B
The lateral accelerometer combination sensor fails an internal self test.
C0186 1A
The lateral accelerometer combination bias exceeds 3 meters/second.
C0186 75
The lateral accelerometer combination signal above allowable range.
Action Taken When the DTC Sets
One or more of the following actions may occur:
| • | The vehicle stability enhancement system (VSES) is disabled. |
| • | Traction control system (TCS) is disabled. |
| • | The TCS/VSES indicators illuminate. |
| • | The driver information center (DIC) displays the Service Traction Control, and or Service StabiliTrak 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. |
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Verification
Ignition ON, observe the scan tool yaw rate and lateral accelerometer sensor parameter. The reading should be the same on all sensors when driving in a straight line at a constant speed greater than 20 km/h (13 mph), and will vary as the vehicle changes direction.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the Yaw Rate/Lateral Accelerometer sensor.
- Test for less than 1 ohm between the ground circuit terminal 1 and ground.
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 4 and ground.
- Ignition OFF, disconnect the harness connector X3 at the Vehicle Stability Control Module (VSCM).
- Ignition ON, test for 0 volts between the communication circuit terminal 52 and ground.
- Test for 0 volts between the communication circuit terminal 72 and ground.
- Ignition OFF, test for infinite resistance between the communication circuit terminal 52 and ground.
- Test for infinite resistance between the communication circuit terminal 72 and ground.
- Test for less than 1 ohm between the communication circuit terminals 72 and terminal 3.
- Test for less than 1 ohm between the communication circuit terminals 52 and terminal 2.
- Test for infinite resistance between the communication circuit 52 and the communication circuit 72.
- If all circuits test normal, replace the Yaw Rate/Lateral sensor.
| ⇒ | If greater than the specified range, test for an open/high resistance in the ground circuit. |
| ⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. |
| ⇒ | If greater than the specified value, test the communication circuit for a short to voltage. |
| ⇒ | If greater than the specified value, test the communication circuit for a short to voltage. |
| ⇒ | If not the specified value, test the communication circuit for a short to ground. |
| ⇒ | If not the specified value, test the communication circuit for a short to ground. |
| ⇒ | If greater than the specified range, test the communication circuit for an open/high resistance. |
| ⇒ | If greater than the specified range, test the communication circuit for an open/high resistance. |
| ⇒ | If not the specified value, test the communication circuits for a short together. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM replacement, setup and programming |
