1999 Porsche 911 Cruise Control Isn't Working

Diagnosing Common Issues with Cruise Control in Your 1999 Porsche 911 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 1999 Porsche 911 cruise control isn't working are failed control module, sensor or switch issues, or throttle actuation problems.
  • Sensor: A faulty sensor can lead to incorrect readings, causing issues with engine performance or triggering warning lights on the dashboard.
  • Control Module: A faulty control module can result in 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 acceleration and poor engine 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 Porsche 911 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 steps to diagnose the cruise control issue in a 1999 Porsche 911?

To effectively diagnose a cruise control issue in a 1999 Porsche 911, start with a systematic approach that prioritizes simpler checks before delving into more complex diagnostics. Begin by inspecting the cruise control module to confirm its proper functionality, as this is a common source of issues. Next, examine the alignment of the clutch switch; any misalignment can disrupt the cruise control system's operation. Following this, conduct Bentley tests to ensure that all related systems are functioning as intended. It’s also crucial to check for voltage at the wires leading to the servo when the cruise control is engaged, as this will help identify any electrical faults. Additionally, verify that the wiring from pin No. 2 of the cruise control connector is correctly connected to the black wire running to fuse B7 at the rear of the fuse panel. If these steps do not resolve the issue, it may be necessary to consult a professional for a more thorough diagnosis. This methodical approach not only aids in identifying the problem but also enhances your understanding of the cruise control system in your Porsche.

What common issues cause cruise control failure in a 1999 Porsche 911?

When troubleshooting cruise control failure in a 1999 Porsche 911, it's essential to understand the common problems that may be affecting the system. One of the primary issues could be a malfunctioning control module, which is responsible for managing the cruise control functions. Additionally, sensor or switch failures can disrupt the communication between the vehicle's systems, leading to a non-responsive cruise control. Another frequent culprit is throttle actuation problems, which can prevent the system from maintaining speed as intended. Over time, components such as the cruise control module may wear out, with issues like capacitor failures or bad solder joints on the control module's PC board becoming more prevalent. By identifying these potential failure modes, DIY enthusiasts can effectively diagnose and address the underlying issues, restoring the cruise control functionality in their Porsche 911.

How urgent is it to address the non-functioning cruise control in a 1999 Porsche 911?

When considering the urgency of addressing the non-functioning cruise control in your 1999 Porsche 911, it's essential to recognize that while this feature enhances driving comfort, its malfunction does not pose an immediate safety risk. For those who frequently embark on long drives, the absence of cruise control can lead to increased fatigue and discomfort, making it a worthwhile issue to resolve sooner rather than later. However, the repair process may involve diagnosing various components such as the Control Module, Sensor, or wiring, which often requires specialized tools and expertise. Therefore, while it’s advisable to have the cruise control system checked and repaired at your convenience, it’s not a critical priority. By taking the time to troubleshoot common issues, such as blown fuses or faulty sensors, you can systematically approach the problem and restore this convenient feature, ultimately enhancing your driving experience without compromising safety.

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