1990 Saab 900 Cruise Control Isn't Working

Diagnosing Common Issues with the Cruise Control System in Your 1990 Saab 900 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 1990 Saab 900 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 1990 Saab 900 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.

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.

What are the initial diagnostic steps to troubleshoot the non-functional cruise control in a 1990 Saab 900?

When troubleshooting the non-functional cruise control in a 1990 Saab 900, it's crucial to adopt a systematic diagnostic approach. Begin by checking the fuse associated with the cruise control system, as a blown fuse can often be the simplest fix. Next, inspect the wiring for any signs of damage, corrosion, or loose connections that could disrupt the system's operation. Testing the cruise control switch is also essential; using a multimeter can help determine if it is functioning correctly. Additionally, examine the vacuum lines for any leaks or damage, as these are vital for the cruise control's performance. The speed sensor should also be verified, since a malfunctioning sensor can prevent the cruise control from engaging. Finally, utilizing a diagnostic scanner to check for error codes can provide valuable insights into any underlying issues. By following these steps, you can effectively diagnose and address the problems with your Saab's cruise control system, ensuring a smoother driving experience.

What are the common problems that could cause the cruise control to stop working in a 1990 Saab 900?

When troubleshooting cruise control issues in a 1990 Saab 900, it's crucial to consider several common problems that could be at play. A faulty cruise control switch is often the first suspect, as it can hinder the system's ability to engage or disengage properly. Additionally, the cruise control module itself may be defective, which can lead to erratic or non-functional behavior. Another frequent culprit is vacuum leaks within the system; these can disrupt the necessary pressure for the cruise control to operate smoothly. Furthermore, a malfunctioning speed sensor can prevent the system from maintaining a consistent speed, while electrical problems, such as blown fuses or wiring issues, can also cause the cruise control to fail. Lastly, don't overlook the brake light switch, as a malfunction here can disable the cruise control when the brakes are applied. By systematically checking these components, DIYers can effectively diagnose and resolve the cruise control issues in their Saab 900.

How urgent is it to repair the non-functioning cruise control in a 1990 Saab 900?

While the non-functioning cruise control in a 1990 Saab 900 may not seem urgent, it is important to consider the potential consequences of neglecting this issue. Although cruise control is primarily a convenience feature, its malfunction could indicate underlying electrical problems that might affect other systems in the vehicle. If left unaddressed, these issues could escalate, leading to more significant repairs and potentially compromising the vehicle's overall performance. Additionally, a properly functioning cruise control system enhances driving comfort, especially on long trips, making it a worthwhile consideration for any DIY enthusiast. Therefore, while immediate action may not be necessary, keeping an eye on the cruise control's performance and investigating any related electrical concerns can help maintain the vehicle's health and ensure a safer driving experience.

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