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.
To effectively troubleshoot the non-functional cruise control in your 1992 BMW 735iL, start by connecting a code reader to the vehicle. This will allow you to check the functionality of the on-off switch and the set/resume switch, which are crucial for the cruise control operation. Next, inspect the brake switches, as they play a significant role in the cruise control system; if they are malfunctioning, they can prevent the system from engaging. Additionally, don't overlook the clutch switch; even if it appears to be working, it can still impact the cruise control's performance. It's also important to ensure that the jakes are functioning properly, as any issues here could affect the cruise control system. If these initial checks do not resolve the issue, consider using an OBD2 scanner to identify any underlying problems, such as a faulty speed sensor or other related faults. By following this structured approach, you can systematically diagnose and address the issues affecting your cruise control system.
When dealing with a malfunctioning cruise control system in a 1992 BMW 735iL, it's essential to consider several common problems that could be at play. One of the first components to check is the steering angle sensor, as a malfunction here can disrupt the cruise control's functionality. Additionally, the control module itself may have faults that prevent proper operation. It's also wise to inspect the power steering fluid levels, as low fluid can impact the system's performance. Another critical area to examine is the rear brake light switch; if this switch is faulty, it can inadvertently signal the cruise control to disengage. Furthermore, sensor issues or specific electrical problems may arise, leading to erratic behavior of the cruise control system. Don't overlook the cruise control cancel circuit, as any problems here can also cause the system to fail. Lastly, if your vehicle is equipped with adaptive cruise control, ensure that the system is functioning correctly and that no debris is obstructing the sensors, particularly around the H emblem. By systematically checking these components, you can identify and address the root cause of the cruise control malfunction, restoring functionality to your BMW.
Repairing the non-functioning cruise control on your 1992 BMW 735iL is not just a matter of convenience; it is a critical safety concern that should be prioritized. An illuminated Check Engine Light (CEL) often accompanies cruise control malfunctions, signaling potential underlying issues with the speedometer or instrument panel that could escalate if left unaddressed. Delaying repairs can lead to significant safety risks, particularly during long drives where maintaining a constant speed is essential. Furthermore, the root cause of the malfunction—whether it be voltage fluctuations or a faulty cruise control switch—needs to be identified and rectified to restore functionality. Ignoring these symptoms can result in not only discomfort while driving but also the risk of further damage to your vehicle. Therefore, addressing the cruise control issue promptly is crucial for ensuring both your safety and the overall performance of your BMW.
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