Circuit Description
The continuously variable road sensing suspension (CVRSS) calculates normal force and transmits a pulse width modulation (PWM) signal to the electronic brake control module (EBCM) via 2 dedicated data lines, one right, and one left. The EBCM supplies the pull-up voltage. The EBCM uses this information to detect rough road conditions and allows for more aggressive braking on rough surfaces.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C1251 RSS Indicated Malfunction
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The CVRSS diagnoses a condition in the road sensing suspension system and sends a serial data message to the EBCM. The CVRSS will typically set a DTC and the EBCM will set this DTC.
Action Taken When the DTC Sets
| • | The EBCM disables the rough road detection function of the vehicle stability enhancement system (VSES) for the duration of the ignition cycle. |
| • | The ABS/traction control system (TCS)/VSES remains functional. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and the DTC is cleared with a scan tool. |
| • | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
This DTC is for information only. As an aid to the technician, this DTC indicates that there are no problems in the ABS/TCS system.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
