1991 GMC V3500 Cruise Control Isn't Working

Diagnosing Common Issues with the Cruise Control System in Your 1991 GMC V3500 and How to Fix Them

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Reviewed by
Andrew Hajjar
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 1991 GMC V3500 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 1991 GMC V3500 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.

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-functioning cruise control in a 1991 GMC V3500?

When troubleshooting the non-functioning cruise control in your 1991 GMC V3500, it's essential to adopt a systematic diagnostic approach. Begin by checking the fuse associated with the cruise control system, as a blown fuse is a common and easily fixable issue that can prevent the system from operating. Next, inspect the wiring for any signs of damage or loose connections, as faulty wiring can disrupt the necessary signals for the cruise control to engage. After ensuring the wiring is intact, test the cruise control switch itself; a malfunctioning switch can be the culprit behind the system's failure to activate. Given the age of the vehicle, it's also crucial to examine the vacuum lines for any leaks or damage, as these can significantly impact the cruise control's functionality. If these initial checks do not resolve the issue, consider using a diagnostic scanner to identify any error codes that may provide insight into more complex problems. Finally, inspect the cruise control module to ensure it is receiving power and functioning correctly, as a faulty module may require replacement. By following this structured approach, you can effectively diagnose and potentially resolve the cruise control issues in your GMC V3500.

What are the common problems that could cause the cruise control to stop working in a 1991 GMC V3500?

When dealing with a malfunctioning cruise control system in a 1991 GMC V3500, it's essential to understand the common problems that may be at play. One of the first things to check is the fuse; a blown fuse can easily disrupt the entire system. Next, consider the brake pedal switch, as a faulty switch can deactivate cruise control whenever the brakes are applied, preventing it from functioning. Additionally, the cruise control module itself may be defective, which can lead to a complete failure of the system. It's also important to inspect for vacuum leaks, as these can hinder the system's ability to engage properly. A faulty speed sensor can further complicate matters, as it is crucial for maintaining a constant speed. Lastly, wiring issues, such as frayed wires or loose connections, can create significant disruptions in the cruise control operation. By systematically checking these components, DIYers can effectively diagnose and potentially resolve the issues affecting their cruise control system.

How urgent is it to repair the non-functioning cruise control on a 1991 GMC V3500?

When evaluating the urgency of repairing the non-functioning cruise control on a 1991 GMC V3500, it's essential to consider both safety and comfort. While cruise control is primarily a convenience feature, its malfunction can lead to driver fatigue during long trips, potentially increasing the risk of accidents. If the system's failure affects your ability to maintain control over the vehicle, it becomes a safety concern that warrants immediate attention. Additionally, if you rely heavily on cruise control for your driving comfort, the inconvenience of its malfunction may prompt you to prioritize the repair. Furthermore, addressing this issue can positively impact your vehicle's resale value, as prospective buyers often look for well-maintained features. Therefore, while the urgency may vary based on personal circumstances, consulting with a mechanic to assess the specific problem is advisable to ensure both your safety and the longevity of your vehicle.

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