Brake Control System - Sensor Cluster DTC'S (59-16)
Publication date: 2008-06-04Reference number: 59-16
BRAKE CONTROL SYSTEM - SENSOR CLUSTER DTC'S
TECHNICAL SERVICE BULLETIN
| VOLVO: | XC90 2005- |
Description
This TNN provides information about the brake control system, specifically, how to diagnose and repair certain issues related to the sensor cluster. The brake control system consists of a number of components. The components covered in this TNN are shown in Fig 1.
The brake control system is used for a number of functions including: Stability control, Traction control, Anti-spin and Active yaw control. For further information, please see VIDA, Design and Function.
When a vehicle is connected to VIDA, all brake control parameters can be analyzed by using Vehicle Communication, see Fig 2. The path to this function is: Diagnostics > Vehicle Communication > BCM (Brake Control Module) > Parameters. Note that there are tabs for descriptions and a graphic window for the parameters.
While driving, the sensors in Fig 1 continuously measure the concerned parameters. At the same time, each parameter is calculated based on input from the other sensors. For example: The yaw rate is measured by the sensor cluster and is as the same time calculated by input from the four wheel speed sensors, the steering angle sensor, and the lateral accelerometer in the sensor cluster.
If the measured and calculated values do not match, a DTC (Diagnostic Trouble Code) is set and the warning light and/or message are displayed.
See Service A below for related DTC's and for possible causes.
Service B below describes the repair for a specific driving situation.
Service
A. DTC: BCM 0121 / C006364 - Signal outside its permitted range
According to our analysis of returned components, these DTC's are usually not caused by a hardware fault with the sensor cluster or BCM. To ensure customer satisfaction with the repair, make sure the basics below are covered. These are the more likely possible sources of DTC's BCM 0121 / C006364.
- Check all cable harnesses and connectors for: the wheel speed sensors; the sensor cluster; the steering wheel sensor; and the BCM. Check for contact resistance and oxidation.
- Make sure that the wheel alignment is within specification.
- Are there any loose or worn out suspension components?
- Calibrate the BCM on a flat surface according to VIDA.
- Make sure that the wheel speed sensors are in the correct position and that the sensors are not dirty or have any metallic components on them.
- Are all four tires the correct specification, and are they all the same brand, type and dimension? Is the tire circumference the same on all four tires?
- Make sure the steering angle sensor works properly.
- While driving straight, does the steering angle sensor measure 0 degrees?
- Is the CAN (Controller Area Network) working properly?
B. DTC: BCM 0127 / C111464 - Angle of lean sensor. Signal outside its permitted range
These DTC's can be set while driving in rather sharp curve at an angle, usually at 20 mph (30 kph) at low engine load, while the steering wheel is held at the same position throughout the curve.
If these DTC's are seen: Perform a BCM software upgrade.