1993 BMW 318is Cruise Control Isn't Working

Diagnosing Common Issues with the Cruise Control System in Your 1993 BMW 318is and How to Fix Them

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Reviewed by
Devin Cabugcal
Written by RepairPal Car Genius
Updated January 14, 2025
0%
30% chance it's the
Sensor
0%
25% chance it's the
Control Module
0%
25% chance it's the
Throttle
0%
20% chance it's
Something else
The most common reasons a 1993 BMW 318is cruise control isn't working are failed control module, sensor or switch issues, or throttle actuation problems.
  • Sensor: A faulty or malfunctioning sensor can lead to incorrect readings, causing issues with engine performance or other systems relying on accurate data.
  • Control Module: A faulty control module can lead to erratic vehicle behavior or failure of various electronic systems due to improper signal processing.
  • Throttle: A faulty throttle body or a defective accelerator pedal position sensor may be causing inconsistent throttle response.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 1993 BMW 318is cruise control isn't working?

Common Repairs

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.

What are the initial diagnostic steps to troubleshoot the non-functional cruise control in a 1993 BMW 318is?

To effectively troubleshoot the non-functional cruise control in your 1993 BMW 318is, start by connecting a code reader to the vehicle's diagnostic port. This will help you identify any error codes that may indicate specific issues within the cruise control system. Next, examine the functionality of the cruise control switches, including the on/off and set/resume buttons, as these are crucial for operation. It's also important to check the brake and clutch switches, as they play a vital role in the cruise control's functionality; even if they seem to be working, a malfunction can still affect performance. After verifying these components, inspect the wiring, particularly the clock spring that connects the steering wheel controls to the cruise control system, to rule out any wiring issues. By following this structured approach, you can systematically diagnose and address the root cause of the cruise control malfunction, ensuring a more efficient and effective repair process.

What are the common problems that could cause the cruise control to stop working in a 1993 BMW 318is?

When diagnosing cruise control issues in a 1993 BMW 318is, it's essential to consider several common problems that may be at play. One of the primary culprits is a malfunctioning steering angle sensor, which can disrupt the system's ability to maintain speed. Additionally, electrical issues such as blown fuses or problems within the instrument cluster can significantly impact the cruise control's functionality. It's also important to check for sensor malfunctions, as individual gauge failures can lead to broader cruise control malfunctions. Specific parts of the cruise control system, including the throttle actuator and control module, should be inspected for proper operation. Lastly, while less common, issues related to the V/n ratio limit can arise, particularly in modified vehicles. By systematically addressing these potential problems, DIYers can effectively troubleshoot and restore the cruise control system to working order.

How urgent is it to address the non-functioning cruise control in a 1993 BMW 318is?

Addressing the non-functioning cruise control in your 1993 BMW 318is is not just a matter of convenience; it is crucial for maintaining the overall safety and functionality of your vehicle. When cruise control fails, it can lead to a less enjoyable driving experience, making long trips more tiring and stressful. Moreover, the malfunction may be a symptom of deeper issues, such as a faulty cruise control switch, damaged wiring, or a malfunctioning module, which could escalate into more significant problems if left unattended. Ignoring these symptoms can result in increased repair costs and potential safety hazards, as a malfunctioning cruise control system may affect your ability to maintain speed effectively. Therefore, it is essential to prioritize the diagnosis and repair of your cruise control system to ensure a smooth and safe driving experience, while also preventing further complications that could arise from neglecting this issue.

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