The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.
When the throttle position sensor fails, the engine's computer tends to overcompensate with fuel, leading black exhaust coming from the tailpipe. There is a strong possibility of engine misfires, and the check engine light will come on.
Throttle position sensors can also develop "dead spots," or certain places along the throttle curve where it doesn't get a reading. When this happens, the above symptoms can occur but then stop when you further press or let off the gas pedal.
When the vehicle speed sensor fails or the wiring harness prevents signal transmission, the speedometer is the first thing that will stop functioning properly. This can be an intermittent issue where the speedometer only works occasionally, the speedometer may cease all function, or the speedometer may read erratically or incorrectly. Also, the traction control and anti lock brake warning lights specific to each vehicle may be illuminated, depending on the design of those systems. You may notice the vehicle hesitate to accelerate, cruise control will not function properly, and the vehicle may not shift properly through all of the gears.
In the event that a wheel speed sensor fails, the ABS, traction control system (TCS) and manufacturer specific stability control system lights will illuminate, informing the driver that the systems are disabled. The vehicle will be more prone to tire slip, and normal driving patterns may need to be adjusted to correct for the loss of computer control. On older vehicle's, the speedometer can be affected, causing illumination of the check engine light as well.
The cruise control switch can cause complete failure of the cruise control feature, but in a lucky scenario only partial functionality will be lost. This means that the cruise control may come on, but that it will not increase in speed automatically, or the cancel button does not work leading the driver to cancel cruise control with the foot brake. In some vehicles, the cruise control light may illuminate, or a warning message may be displayed due to lack of functionality.
A faulty cruise control module will simply result in deactivation of cruise control settings. This is because a detected error in the cruise control system could lead to hazardous driving conditions, so the module will be disabled, and the cruise control system warning light will be displayed. This will be a different message depending on make and model, and a warning light or message may be displayed on the driver instrument cluster.
To effectively diagnose the non-functioning cruise control in your 1997 BMW 528i, start with a thorough examination of the cruise control switch, as it is the primary interface for activating the system. Ensure that the switch is intact and operational, as any damage can disrupt signal transmission to the cruise control module. Next, consult the wiring diagrams to inspect the connections between the steering wheel controls and the cruise control system, paying particular attention to the clock spring, which can affect functionality. It’s also crucial to verify that the cruise control buttons are receiving the correct input values; this can be done by checking the engine controller's measurement block for any changes when the buttons are pressed. If you encounter specific error messages, such as "ACC is unavailable," follow the recommended troubleshooting steps to address these issues. Lastly, inspect the internal components of the cruise control unit, particularly the electrolytic capacitors, as faulty parts can significantly impair performance. By following these steps, you can systematically identify and resolve the issues affecting your cruise control system.
When the cruise control in a 1997 BMW 528i ceases to function, several common issues may be at play. One of the primary culprits is the rear brake light switch, which is known to fail and can disrupt the cruise control system's operation. Additionally, problems with the turn signal switch can also interfere with cruise control functionality, as these components are interconnected. Another significant factor to consider is the speed sensor; if this sensor is faulty, it can lead to unreliable cruise control performance or complete failure. Lastly, malfunctions in the steering angle sensor or the control module can further complicate the situation, as these elements are crucial for the proper functioning of the cruise control system. By systematically checking these components, DIYers can effectively diagnose and address the issues, restoring the cruise control to its intended operation.
When contemplating the urgency of repairing the non-functioning cruise control in your 1997 BMW 528i, it's essential to weigh your driving habits against the potential consequences of inaction. While cruise control is primarily a convenience feature, neglecting its repair can lead to complications that may affect your overall driving experience. For those who frequently embark on long highway journeys, the absence of cruise control can result in increased fatigue and discomfort, making the repair more pressing. Conversely, if your driving is mostly confined to city traffic, the urgency may diminish. However, it's crucial to recognize that the underlying cause of the cruise control failure could be indicative of broader issues within the vehicle. Ignoring these symptoms might not only prolong your discomfort but could also lead to more significant mechanical problems down the line. Therefore, assessing your reliance on this feature and the potential risks associated with its malfunction can guide you in determining whether to prioritize this repair.
Read about related problems experienced by other BMW 528i drivers like you.
See what others are asking about their BMW 528i. Get answers from RepairPal's community of auto experts and enthusiasts.