1999 Chrysler 300M Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your 1999 Chrysler 300M 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
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25% chance it's the
Throttle
0%
20% chance it's
Something else
The most common reasons a 1999 Chrysler 300M 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 1999 Chrysler 300M 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 steps to diagnose the non-functioning cruise control in a 1999 Chrysler 300M?

To diagnose the non-functioning cruise control in a 1999 Chrysler 300M, begin with the simplest checks to avoid unnecessary complications. Start by inspecting the fuse associated with the cruise control system, as a blown fuse is a common and easily fixable issue. Next, examine the cruise control switch to ensure it is operational; a malfunctioning switch can prevent the system from engaging. Following this, check the brake pedal switch, which is crucial for safety, as it disengages the cruise control when the brake is pressed. If these components are functioning correctly, turn your attention to the speed sensor, as its failure can disrupt the cruise control's operation. Additionally, inspect the vacuum lines for any leaks, as these can significantly impact the system's performance. Finally, if the problem persists, utilize a diagnostic scanner to retrieve any error codes that may provide further insight into the underlying issue. By systematically addressing these areas, you can effectively diagnose and potentially resolve the cruise control malfunction in your Chrysler 300M.

What are the common problems that could cause the cruise control to stop working in a 1999 Chrysler 300M?

When troubleshooting the cruise control system in a 1999 Chrysler 300M, it's essential to consider several common problems that could be at play. A failed control module, sensor, or switch can disrupt the system's functionality, while throttle actuation issues may prevent the cruise control from maintaining speed. Additionally, a vacuum actuator failure or damaged vacuum hoses can hinder the system's operation, as can problems with the cable linking the actuator. A faulty cruise control switch or a blown fuse or relay may also be culprits, leading to a complete system failure. Furthermore, underlying engine or transmission issues can impact cruise control performance, as can a malfunctioning brake light or brake switch, which may inadvertently signal the system to disengage. Lastly, if the vacuum release valve requires replacement, it could also contribute to the problem. By systematically checking these components, DIYers can effectively diagnose and address the issues affecting their cruise control system.

How urgent is it to address the non-functioning cruise control in a 1999 Chrysler 300M, considering potential safety risks and further damage?

When it comes to the non-functioning cruise control in a 1999 Chrysler 300M, the urgency to address this issue cannot be overstated. While it may not seem like an immediate emergency, neglecting the malfunction can lead to significant safety risks and discomfort during driving. A malfunctioning cruise control system can distract the driver, especially on long trips where maintaining a steady speed is crucial. This distraction can increase the likelihood of accidents, making it essential to prioritize repairs. Additionally, the physical strain of manually controlling the vehicle's speed for extended periods can lead to driver fatigue, further compromising safety. Beyond immediate safety concerns, addressing the issue promptly can prevent potential underlying electrical or mechanical problems from escalating, which could save you from costly repairs down the line. Therefore, while it may be tempting to overlook the cruise control issue, taking the time to diagnose and fix it not only enhances your driving experience but also ensures your safety on the road.

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