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.
When troubleshooting the non-functioning cruise control in a 1991 Audi 90 Quattro, it's essential to adopt a methodical diagnostic approach. Begin by checking the fuse associated with the cruise control system, as a blown fuse is a straightforward issue that can easily be resolved. Next, inspect the wiring for any visible damage or loose connections, as faulty wiring can disrupt the system's functionality. Testing the cruise control switch is also crucial, as a malfunctioning switch is a common culprit behind cruise control failures. Given the age of the vehicle, it's wise to examine the vacuum lines for any leaks or blockages, which can significantly impact the system's operation. Utilizing a diagnostic scanner to check for error codes can provide valuable insights into specific issues affecting the cruise control. Finally, inspect the cruise control module for signs of damage or corrosion, as a defective module can prevent the system from engaging. By following these steps, you can effectively diagnose and potentially resolve the cruise control issue in your Audi, ensuring a smoother driving experience.
When dealing with cruise control issues in a 1991 Audi 90 Quattro, it's essential to understand the various components that could be at fault. A faulty cruise control switch is often the first suspect, as it directly controls the system's engagement and disengagement. Additionally, vacuum leaks can significantly impact the system's performance, leading to a loss of pressure that prevents proper operation. Another critical component is the speed sensor; if it malfunctions, it disrupts the communication necessary for the cruise control to function correctly. It's also worth checking the fuse associated with the cruise control circuit, as a blown fuse can completely disable the system. Furthermore, the brake light switch plays a vital role in cruise control functionality; if it has issues, it may prevent the system from activating, especially when the brake pedal is pressed. Lastly, inspect the throttle cable for any signs of wear or damage, as a malfunctioning cable can hinder the cruise control's ability to maintain a steady speed. By systematically examining these components, DIYers can effectively troubleshoot and potentially resolve cruise control problems in their Audi.
Repairing the non-functioning cruise control in a 1991 Audi 90 Quattro should be viewed as a priority due to its implications for safety and driving comfort. A malfunctioning cruise control system can lead to increased driver fatigue, as maintaining a consistent speed becomes a manual task, which can distract from the road and elevate the risk of accidents. Additionally, the convenience of cruise control allows drivers to relax during long journeys, making it an essential feature for those who frequently travel on highways. Beyond immediate safety and comfort concerns, neglecting this repair could also impact the vehicle's resale value. A fully operational cruise control system is often seen as a desirable feature by potential buyers, and addressing this issue can enhance the overall appeal of the car. Therefore, while it may not be critical for the vehicle's basic operation, timely repair of the cruise control is advisable to ensure a safer, more comfortable driving experience and to maintain the car's value in the long run.
See what others are asking about their Audi 90 Quattro. Get answers from RepairPal's community of auto experts and enthusiasts.
Read about related problems experienced by other Audi 90 Quattro drivers like you.