PADM Error

As I mentioned recently on a Twitter Space, while driving my newly purchased early 991 Carrera 4 GTS, I suddenly noticed a PADM error warning on the instrument panel.

The error is displayed in white (there also seems to be a yellow version), so it doesn’t affect driving and the car runs normally without any issues.

From my research across various SNS platforms, this PADM error appears to be a common fault. It’s especially frequent in the 981 series, followed by the 991 and 718 models. Overseas cases show that although rare, some 992 owners have also experienced it.

I was aware of the PADM error issue when I bought the 991, so I was mentally prepared for a possible failure someday—but I never expected it to happen so soon.

Here, I’d like to summarize what I’ve learned about this PADM failure.

What is PADM?

PADM stands for Porsche Active Drivetrain Mount, an electronically controlled engine mount system equipped on cars with the Sport Chrono Package.

Dynamic engine mount on the 911

Engine mounts absorb vibrations to prevent them from being directly transmitted to the body. The softer the mount, the better it absorbs vibrations, improving ride comfort—but this also means some engine power is absorbed and lost, reducing responsiveness and handling.

Conversely, a stiffer mount improves responsiveness but worsens ride comfort.

PADM electronically adjusts the stiffness of the mounts to balance ride comfort and responsiveness.

Specifically, it continuously passes electricity through a magnetic material to variably control the mount’s stiffness. Normally, it adjusts based on parameters like engine RPM. When cornering causes uneven engine load, it stiffens the side under more load to enhance handling. In Sport Plus mode, it stiffens the mounts to the maximum to boost vehicle dynamics.

If you’ve driven a Porsche with the Sport Chrono Package in Sport Plus mode, you might have felt the car tighten up and become more responsive—that effect is partly thanks to PADM.

Since this failure was a rare opportunity, I tested Sport Plus mode repeatedly, and compared to normal operation, the car’s response changes were noticeably reduced. While shift control and engine power feel improved, the sensation of the body tightening up almost disappears, showing just how significant PADM’s contribution is.

How Much Does PADM Repair Cost?

PADM parts themselves are quite expensive—at the time of writing, one side costs about 220,000 yen. Since these parts come in pairs, replacing both would cost around 440,000 yen just for parts.

Adding labor costs, prices vary by dealer, but from what I’ve confirmed, replacing one side including parts runs about 300,000 yen, and replacing both sides costs around 500,000 yen.

Engine mount on the 991

Engine mount on the Boxster/Cayman (981), which also serves as the transmission mount.

Because the repair cost is so high, some owners opt to use used parts or replace the mounts with standard engine mounts (for cars without the Sport Chrono Package) even on Sport Chrono-equipped cars. They then have non-dealer workshops perform coding to prevent error warnings. Standard engine mounts cost about 50,000 to 60,000 yen.

However, personally, I think it’s a shame to lose the fantastic PADM feature, which is a highlight of the Sport Chrono Package. Also, when you eventually sell the car, the next owner might unknowingly get a car with standard mounts instead of PADM—something quite unfortunate.

Why Warranty Matters for Porsche Used Cars

In my case, although the car was used, it was still under the dealer’s warranty, so the repair was free of charge.

Used car warranties often come with many conditions, and I’d heard stories about dealers hesitating to cover repairs, so I wasn’t expecting much.

However, the Universe Nagoya dealership where I bought the car was extremely helpful. When I called to report the issue, they apologized sincerely and said, “Please get the repair done immediately at a nearby Universe or Porsche dealer.” They also said, “Have the dealer send us the repair estimate. We will cover the costs.” Their response was very reassuring.

Their outstanding support inspired me to share this experience in my blog. (I never mentioned that I’m a blogger, so this was not a special favor.)

Without warranty, this repair would have been a significant expense.

Major repairs on Porsches often run into hundreds of thousands of yen. Therefore, when buying a used Porsche, I recommend purchasing from certified pre-owned programs or dealers with solid warranties.

Also, even if you buy a used Porsche from a non-dealer without warranty, you can still enroll in an extended warranty at a Porsche dealer if you meet certain conditions (note that you cannot enroll within three months after ownership transfer).

I plan to enroll in Porsche’s extended warranty going forward. A two-year plan for the 911 costs about 280,000 yen, which breaks down to about 140,000 yen per year or just over 10,000 yen per month—quite reasonable compared to typical Porsche repair costs, and it offers great peace of mind when driving.