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 diagnosing the non-functioning cruise control in a 1999 Lexus GS400, it's crucial to follow a methodical diagnostic approach that prioritizes simpler fixes before delving into more complex issues. Begin by checking the fuse related to the cruise control system, as a blown fuse is a common and straightforward problem that can easily be rectified. Next, inspect the cruise control switch to confirm its proper operation; a faulty switch can prevent the system from engaging altogether. After ensuring the switch is functional, examine the brake pedal switch, which is essential since the cruise control automatically disengages when the brake is pressed. If these components are in good working order, proceed to verify the vehicle speed sensor, as it plays a critical role in the cruise control's functionality. Additionally, inspect for any vacuum leaks in the lines and connections, as these can adversely affect the system's performance. If the cruise control still does not function, utilize a diagnostic scanner to check for error codes that may reveal specific issues within the cruise control system. By adhering to this structured approach, you can effectively identify and address the underlying problems with your cruise control system.
When troubleshooting cruise control issues in a 1999 Lexus GS400, it's important to consider several common problems that could be at play. A faulty cruise control switch is often the first suspect, as it can prevent the system from engaging properly. Additionally, a blown fuse within the cruise control circuit can lead to complete system failure, making it a straightforward fix if identified early. Vacuum leaks are another frequent culprit, as they can disrupt the necessary pressure for the cruise control to function effectively. Furthermore, a defective speed sensor may cause the system to malfunction or disengage unexpectedly, while issues with the brake light switch can inhibit activation altogether. Lastly, a malfunctioning throttle cable can hinder the cruise control's ability to maintain speed. By systematically checking these components, DIYers can accurately diagnose and resolve the cruise control problems in their Lexus GS400, restoring functionality and enhancing driving comfort.
When evaluating the urgency of repairing the non-functioning cruise control in a 1999 Lexus GS400, it's essential to recognize that while the immediate safety risks may not be severe, the long-term consequences of inaction can be significant. A malfunctioning cruise control system can lead to driver fatigue, as maintaining constant speed manually can be tiring, especially on long journeys. This fatigue can increase the likelihood of distractions, potentially compromising safety. Additionally, the absence of cruise control diminishes driving convenience, making long trips less enjoyable and more physically taxing. Furthermore, without the ability to maintain a steady speed, fuel efficiency may suffer, leading to increased fuel costs over time. Therefore, while it may not be an emergency repair, addressing the cruise control issue promptly can enhance your driving experience, improve comfort, and contribute to better fuel economy. For DIY enthusiasts, tackling this repair can be a rewarding project that not only restores functionality but also ensures a safer and more pleasant driving experience.
Read about related problems experienced by other Lexus GS400 drivers like you.
See what others are asking about their Lexus GS400. Get answers from RepairPal's community of auto experts and enthusiasts.