What 15 owners told NHTSA about the 2017 Porsche Cayenne E-hybrid Coupe

Case Number: 1170739 – Additional Evidence Submission I would like to provide an additional document for Case #1170739. The manufacturer (Porsche Cars North America) stated in writing that the vehicle is “safe to drive even with warning indicators illuminated,” but in the same communication offered a rental vehicle if I found this “inconvenient.” These two statements cannot logically coexist, and they raise concerns that the manufacturer may be minimizing or mischaracterizing a potential safety-related defect. Furthermore: The warning indicators involve the coolant and fuel systems of an E-Hybrid model, which may be connected to thermal management and combustion-related safety. The vehicle remained in the dealer’s possession for an extended period during repeated repair attempts. During a visit, I found the hood partially open while the vehicle was being stored long-term, raising questions regarding proper safety and storage protocols. Additional system warnings appeared after prolonged non-operation, suggesting possible deterioration related to improper storage or incomplete diagnostics. I respectfully request NHTSA’s assessment of whether it is appropriate for a dealer or the manufacturer (Porsche Cars North America) to advise a customer to operate a vehicle on public roads while warning indicators are illuminated. From a consumer’s standpoint, this does not appear reasonable or safe, and I wish to operate my vehicle only in a condition that is objectively safe for road use. The fact that such guidance was provided to me is deeply concerning, and I would appreciate the agency’s evaluation of whether this type of advice aligns with I am submitting the manufacturer’s email for your review, as it appears inconsistent with standard safety guidance and may reflect an attempt to address the matter through customer-service accommodations rather than technical evaluation. Please add this information and attached documentation to my existing case file. Thank you.

NHTSA ODI 11704535

I am reporting a series of safety-related defects involving the electrical, cooling, and fuel systems of my 2021 Porsche Cayenne E-Hybrid. The vehicle was initially brought to the authorized Porsche dealership due to an electrical system error, and the dealer kept the vehicle for an extended period. After approximately five months, the vehicle was returned to me without a clear explanation of the root cause or details of the repair. The very next day after receiving the vehicle, a coolant temperature warning appeared while driving, indicating abnormal engine overheating. This created an immediate safety hazard, as overheating can lead to sudden engine failure, loss of power, or a potential fire risk. I returned the vehicle to the dealership again for further repairs. Afterward, another serious issue occurred: because this is a hybrid vehicle, I went to refuel, but the fuel door would not open, and a fuel system error warning appeared again. This made the vehicle unsafe to operate, especially while already on the road. Due to these repeated failures, I was required to tow the vehicle multiple times. These problems — electrical malfunction, coolant overheating during driving, fuel system errors, and a non-functional fuel door — occurred repeatedly even after prolonged service by the dealership. The combination of electrical faults, overheating risk, hybrid system malfunction, and fuel system failure presents a significant safety concern. I will provide additional documentation to support this report. I request that NHTSA review this case to determine whether an investigation is warranted, as these issues may indicate a broader defect affecting this model.

NHTSA ODI 11703739

When the weather drops below 0 celsius, the hybrid battery fails with a hybrid battery failure message. The Porsche dealer said this is a known issue and there is no fix. I've been stuck several times in the past 3 years up in the mountains when the temperature drops suddenly and there are no services within 100's of miles to even tow it to get a fix. I just have to wait for the temperature to warm up to start the car. There is currently no bypass to switch to gas only which would solve the issue. If you look at the pic, there is plenty of gas in the car.

NHTSA ODI 11636091

Porsche and VW has a drainage issues with certain model vehicles. The drainage plug is set in the trunk near the battery, main system cpu and amplifier. Water gets drain into the lower compartment of the trunk and causes electrical issues with the vehicle. It's been a design flaw from porsche since before the Cayenne was created. To repair the damage it cost upwards of $3,000 per damage battery, electrical components, amplifier are all billed separate. Porsche warranty refuses to honor the design flaws in correct the issues. Owners are not made aware of the issue until it becomes an issue then porsche wants no part to do with it. The drainage location can cause an electrical fire and engine malfunction while driving.

NHTSA ODI 11508794