Fleets continue to adopt advanced driver assistance system (ADAS) technologies in increasing numbers. These systems must be properly maintained to operate most effectively. A major risk of improperly maintained systems is they will be unavailable or not perform to their fullest capacity. Driver frustration can also result when a system doesn’t operate to expectations, which can hamper acceptance of the technology.
The latest installment of the Bendix Tech Tips series shares advice on maintaining ADAS technologies so that they provide the most benefit. It offers guidance on components including antilock braking and stability systems, radar, cameras, and electronic control modules.
ABS and Stability Control
ADAS technologies are built on the foundation of antilock braking systems (ABS) and electronic stability control (ESC) technologies. The ADAS system may not be available if there is a fault with the ABS or ESC systems.
“One ABS concern centers on wheel-speed sensors, which can be susceptible to chassis harness issues such as rubs and chafing, as well as issues occurring when service is done at the wheel-end,” said Brian Screeton, Bendix manager for technical training and service. “The sensor may become nonfunctional, a wire may be severed, or a sensor is not close enough to the tone ring.”
An issue that may arise for stability control can be the steering angle sensor falling out of calibration, which can sometimes happen after a front-end alignment. After any work done on the front end, it’s important to calibrate the sensor.
“Another stability control issue is rare but does occur,” Screeton said. “It’s the incorrect placement of a lateral acceleration/yaw rate sensor after work on the frame rail or chassis modifications. If this sensor is moved or not returned to the correct orientation, then a fault may result with the stability control system.”
Sometimes systems can show a diagnostic trouble code (DTC). Screeton notes that a simple key cycle of the ignition key – done off road in a safe area – may clear it. DTCs like this can be caused by road conditions or the terrain that the vehicle is operating in. Always first try to clear the DTC by restarting the vehicle. If it returns after restarting, then take the vehicle to a qualified repair facility immediately.
Focus on the Radar
Some radar issues, if they occur, can be caused by sensor misalignment, vehicle wiring, or active DTCs in other components of the vehicle – like the engine, for example. Modern or next-generation radars are better at adjusting to minor sensor alignment issues than the radars on earlier advanced driver assistance systems.
It’s important to have all radar issues evaluated by a trained professional to ensure that the system is working properly.
“Radar misalignment means that the radar is not pointing in the right direction,” Screeton said. “This is due usually to improper installation after a repair or after a collision with something that strikes the radar or its mounting. For Bendix, realigning the radar involves following the procedure in the corresponding Bendix service data sheet, searchable at B2Bendix.com.”
In addition, Screeton advised, be sure to also check the bracket for damage and the mounting surface on the chassis. The appropriate repair or replacement of these components may assist in ensuring proper radar alignment is maintained.
Because the radar is on the front of the vehicle, the connector can be exposed to many chemicals, especially in climates where snow and ice require salt, sand, or other substances to help maintain traction. Check to ensure the connector is properly covered, sealed, and secured. This step will help minimize the corrosion that may occur from repeated exposure to road chemicals.
“Remember, too, that radars are designed to detect when they don’t ‘see’ the environment as expected,” Screeton said. “This functionality is typically referred to as radar blindness, which may occur if the radar doesn’t detect a valid object for a certain amount of time. Too few valid radar targets over a period of time can cause the radar to indicate a DTC. This might happen on long stretches of barren highway or desert where other vehicles and radar targets are nonexistent. Typically, an ignition key cycle will reset the radar and the system will resume.”
Focus on the Camera
Camera issues, if they occur, may be linked to camera placement, blindness, or the chassis wiring harness. The first step is to ensure the camera is plugged in and connected. Then keep the following in mind:
- Chassis wires that are frayed, cut, or improperly repaired may create issues with the camera – just as with other vehicle systems. For non-obvious issues, always check the chassis harness first.
- “Camera blindness is usually a temporary, self-correcting occurrence, possibly due to sun and/or fog,” Screeton said. “However, if the camera is blocked by something – like a large bug or a piece of tape – then this will also cause a problem.”
- Has the windshield been replaced? If so, then install the camera using the correct bracket in the original OEM installation location to ensure proper function.
For any repairs associated with potential camera issues, follow the procedure in the corresponding Bendix service data sheet, searchable at B2Bendix.com.
Issues With Software and the ECM
It’s possible that issues with Bendix systems can result when improperly installed or incompatible aftermarket components are added that use the vehicle’s J1939 datalink network.
Frequently, according to Screeton, connectors and connection types are the reason.
“However, issues involving aftermarket component compatibility also create communication concerns,” he said. “Don’t overlook a chassis wire that has rubbed on a metal piece creating a shorted or an open circuit – it typically leads to the inability to connect to the component for diagnostics since diagnostics is performed using the same 1939 CAN communication lines.”
And note this critical point, said Screeton: If the engine electronic control module (ECM) is replaced, then the replacement ECM must be correct for the truck. Bendix’s stability control electronic control units (ECUs) require a match to the VIN to ensure the proper parameters are uploaded for the system.
Tools at Hand
Careful review of the operator’s manual by every driver is essential to ensure they are aware of the ADAS system alerts and notifications expected during operation. It’s especially important that drivers know how the system is supposed to operate, as well as its limitations, so they can better understand if or when something isn’t working properly.
“Having a diagnostic tool that shows the DTCs of the full vehicle is important, as well,” Screeton said. “The diagnostic software for Bendix systems is Bendix® ACom® AE. When connected to a vehicle, the software automatically detects and gathers active and inactive DTCs from all Bendix electronic control units on the vehicle, as well as key vehicle ECUs, like the engine and transmission.”
Screeton encourages technicians to take advantage of available training. Bendix offers three- and two-day Brake School sessions, along with virtual classes and the Bendix On-Line Brake School at brake-school.com. The training helps technicians better understand, troubleshoot, and repair systems. The Bendix On-Line Brake School courses are accessible for no charge when users register with the site.
“Remember that ADAS systems, like vehicles, can be unique,” Screeton noted. “One-size-fits-all training isn’t going to be as helpful as training focused on repairing the specific system of concern.”
The issues described in this installment of Tech Tips are not meant to exhaustively cover what can occur with ADAS technologies, nor are they applicable to all technologies on all vehicles. The content refers to Bendix® advanced driver assistance systems, not autonomous vehicle systems or systems offered by other companies. Information regarding system repairs for specific systems should be referenced to ensure proper repair, maintenance, and operation of the system.
Bendix emphasizes that advanced driver assistance technologies complement safe driving practices. No commercial vehicle safety technology, including Bendix safety technologies, replaces a skilled, alert driver exercising safe driving techniques and proactive, comprehensive driving training. Responsibility for the safe operation of the vehicle remains with the driver at all times. Never wait for the system to intervene. Every driver should carefully review the operator’s manual and be trained by the fleet or vehicle owner on the proper operation and limitations of the ADAS system during operation.
Support on Bendix ADAS technologies is available by calling the Bendix Tech Team at 1-800-AIR-BRAKE.
