Cruise Control Problems of Porsche Cayenne

2018 Porsche Cayenne: at highway speeds, randomly a serious unsafe to operate �service necessary� warning appears on the instrument panel and the cruise control malfunctions. With the service necessary warning indicated, the vehicle is unsafe to operate. This unsafe vehicle is not drivable with cruise control for approximately the next hour. This breakdown is known to Porsche (via their communications with me) and they are unable to rectify the error. In a 2020 Porsche Cayenne this failure has been rectified. Attached, invoices from five visits to Porsche dealerships, all during the warranty period. Attached also photographs taken on various days, times and speeds, and traffic conditions of the service necessary warning on instrument panel and cruise control malfunctions.

See all problems of the 2018 Porsche Cayenne 🔎.

While adaptive cruise control is engaged the vehicle will brake on its own. This occurs when there are no other vehicles or objects in sight. The vehicle applies the brakes hard enough where if another car is following closely it could rear-end my vehicle. I have had the car in to circle Porsche 5-6 times with no resolve. This was first reported to the dealer on June 29, 2015.

See all problems of the 2014 Porsche Cayenne 🔎.

The factory programming of the computer and speed control is incorrect. Porsche states that the vehicle is operating within characteristics and specifications [and according to us law a variance of up to 18% is allowed in the speedometer. ] however, Porsche has taken the us law to mean that it is allowed to intentionally program its computers to the same specifications as analog gauges. Porsche cannot demonstrate that the inaccuracy in the speedometer is not effecting the hybrid operations of the vehicle. The inaccurate speed reading may also create inaccurate odometer readings. In addition the vehicle has problems with hard braking which is especially pronounced when the vehicle is under cruise control. And in certain instances there is lag on acceleration. Porsche has refused to reprogram the speedometer controls to actual speed. Given that the only problems on the vehicle are related to the speed of the vehicle, it seems that Porsche should be capable of providing a solution by reprogramming the onboard computers.

See all problems of the 2011 Porsche Cayenne 🔎.