Diagnostic Instructions
DTC Descriptor
DTC C0252 00: Implausible Control
Circuit/System Description
The ESP 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 vehicles yaw motion
by applying differential braking to the wheels. The amount of differential braking
applied to the left or right front wheel is based on both the yaw rate error and side
slip rate error. The side slip rate error is a function of the lateral acceleration
minus the product of the yaw rate and vehicle speed.
Conditions for Running the DTC
• | Ignition voltage is greater than 8 volts. |
Conditions for Setting the DTC
• | A yaw rate sensor fault occurs with the vehicle speed between 22 km/h
(13.6 mph) and 100 km/h (62.1 mph). |
• | The steering angle sensor fault occurs within a 10 second period while
the vehicle is driven below 100 km/h (62.1 mph). |
• | The steering angle sensor fault occurs within a 5 second period while
the vehicle is driven above 100 km/h (62.1 mph). |
• | All four ABS solenoids are continuously maintaining/releasing pressure
during ABS control within a 1.28 second period. |
Action Taken When the DTC Sets
• | The EBCM disables the Antilock Brake System (ABS)/Traction Control System
(TCS)/Electronic Stability Control (ESP)/Electronic Brake Distribution (EBD) for the
duration of the ignition cycle. |
• | The multi function display (MFD) displays the ABS Fault message. |
• | The multi function display (MFD) displays the Traction Ctrl Off message. |
• | The multi function display (MFD) displays the Stability Ctrl Off message. |
Conditions for Clearing the DTC
• | The condition for setting 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. |
• | The DTC can be cleared using a scan tool. |
Diagnostic Aids
• | This DTC will set if there is a mismatch between the data supplied by
the sensors to the EBCM. |
• | This DTC will set when there is a sensor is installed incorrectly or is
the incorrect type. |
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
Scan Tool Reference
Control Module References
Circuit/System Testing
- Using the scan tool verify that no other steering angle sensor or yaw
rate sensor DTCs are set as current.
- Calibrate/program the EBCM.
- Ignition ON, using a scan tool view the current DTCs.
⇒ | If DTC C0252 is set to current, inspect steering angle/yaw rate sensor
mounting and version number to confirm correct installation and type. |
Repair Instructions