• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
5-Volt Reference | C0186 00 C0196 00 | C0186 00 C0196 00 | C0186 00 C0196 00 | -- |
Yaw Rate Signal | C0196 00 | C0196 00 | C0196 00 | C0196 28,1A,09 |
Low Reference | C0186 00 C0196 00 | C0186 00 C0196 00 | C0186 00 C0196 00 | -- |
The vehicle stability enhancement system (VSES) is activated by the electronic brake control module (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the wheels.
• | The ignition voltage is greater than 9.6 volts. |
• | The vehicle is stopped or the vehicle speed is greater than 45 km/h (28 mph). |
One of the following conditions exist:
• | The yaw/lateral combination sensor signal output voltage to the EBCM is less than 0.15 volt or greater than 4.85 volts. |
• | The vehicle speed has reached at least 15 km/h (9 mph) from a stop more three times during the same ignition cycle. During the time the vehicle is stationary, the yaw rate signal value is more than 7 deg/sec for 2 seconds. |
• | When vehicle speed is more than 25 km/h (16 mph) in a turn the difference between the yaw rate, steering angle, lateral acceleration, and wheel speed sensor values are not correlated three consecutive times. |
• | Yaw rate changes greater than 20 deg/sec in 6 ms four times in one second. |
• | The yaw/lateral combination sensor fails an internal self test. |
The yaw frequency measured is not between 13400.0-14600.0 Hz for more than 200 msec.
• | The EBCM turns OFF the 5-volt reference circuit, until the ignition is cycled. |
• | The EBCM disables the VSES for the duration of the ignition cycle. |
• | The driver information center (DIC) displays the Service Stabilitrak message. |
• | The ABS/TCS remains functional. |
• | 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. |
• | If the yaw and lateral accelerometer sensor is disconnected, DTCs will set and the EBCM will not provide 5-volt reference. |
• | The yaw rate and lateral accelerometer sensors are located in one unit and cannot be serviced separately. |
Antilock Brake System Schematics
Control Module References for scan tool information
⇒ | 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 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 ground or an open/high resistance. If the circuit tests normal, replace the EBCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for EBCM replacement, setup, and programming