How One Man Made the Porsche 993 More User-friendly for Americans
Porsche 993 automatic immobilizer can be disabled without removing the security feature altogether.
If you own a Porsche 993 from the 1995 through 1998 model years, you are surely familiar with the automatic immobilizer system. This system engages 90 seconds after the engine has been shut off and it prevents the engine from being started again until the key fob has locked and unlocked the doors. This sounds like a nice security feature, but for many owners, it is more of an annoyance. For years, owners have been seeking a way to defeat the automatic immobilizer, and there were some hacks to prevent the system from engaging, but those early solutions were problematic. Not only did you have to perform some irreversible modifications, but once the automatic immobilizer was disabled, the entire immobilizer system would no longer function.
Fortunately, an electrical engineer and Porsche 993 owner named Jay Mingrone came up with the IMMO BLOCK. This simple plug-and-play device prevents the automatic immobilizer from engaging, but the immobilizer system will still work when the doors are locked with the fob.
To get more information on the IMMO BLOCK, we reached out to Mingrone, who explained how he came to create this convenient gadget for the Porsche 993 models in the North American and Saudi Arabian markets.
Porsche 993 Automatic Immobilizer
If you aren’t familiar with the automatic immobilizer in the Porsche 993, here is a quick explanation of how it works in stock form.
Say that you stop to get gas with your Porsche 993. You probably don’t lock the doors when you get out to pump gas, so after you pump your gas, you get back into the car and try to fire it up, but the engine wont start. The immobilizer is engaged and to get the car to start, you have to lock and unlock the doors with the key fob. The idea is that if the car is mistakenly left unlocked, the system prevents a thief from hot-wiring the car. In theory, it is a good idea, but owners don’t like the fact that they have to either keep their Porsche locked in the garage or cycle through the lock-unlock sequence to get the car to start.
Along the same lines, many people who take their Porsche 993 to the race track aren’t likely to keep the doors locked every time they come into the garage area. However, to get the car to fire to head out onto the track or do some tuning work, the driver has to lock and unlock the doors with the key fob.
Another key issue is that when you take your 993 in for service at a shop where they aren’t familiar with the system, owners will often get a call because their car won’t start. Plus, in addition to being an annoyance, this system leads to unnecessary wear of the locking mechanism and the key fob, so Mingrone created the IMMO BLOCK to disable the automatic aspect of the system without completely disabling the immobilizer system.
How IMMO BLOCK was Created
We asked Mingrone what led him to create the IMMO BLOCK and below, you will find his explanation.
Initially all I wanted to do was hack the feature out of my own car. As an electrical engineer, I felt confident I could find a solution and I love a challenge. I was aware you could PAY people to defeat the immobilizer, but it was invasive and risky – remove seat, grind off security bracket, remove ECU and immobilizer, send off to be modified, wait a few weeks, then put the whole thing back together and hope it worked. All of this for $700 to $1100, plus you end up with a “modified” car with no anti-theft protection and side effects (the warning light on the dash stays on). One method also requires a relay to bypass the starter interlock. The solution I found not only worked, it was an easy DIY. The real breakthrough was when I discovered a way to make it 100% plug and play – the Holy Grail! At that point I decided to turn it into a product. The first step was to enlist Rennlisters to beta test prototypes to make sure it didn’t just work in a 97. I had plenty of volunteers! That proved successful so it was full steam ahead. That was Nov, ’19. The goal was to get everything done by 1 March in time for the next driving season. Everything went smoothly and the units were offered in a group buy shortly first week of March for less than half the price of the invasive, risky, non-reversible alternatives.
In addition to creating a fix for the automatic immobilizer, Mingrone wanted his product not to cause any unintentional side effects. The first iteration of the product caused stand-by current to rise by a significant amount and over a period of time, that could cause the battery to die. The second version didn’t have any increased current draw, but it required owners to tap into a wire under the dash. Since not everyone will be cool with splicing into their under-dash wiring, Mingrone kept working on a cleaner solution. That solution was the IMMO BLOCK shown here, which is 100% plug-and-play without any wiring changes.
Mingrone went on to explain that this product only applies to the Porsche 993 in North America and Saudi Arabia, where the cars all use the door chime system. That is where the IMMO BLOCK attaches. He is looking at making a similar unit for the rest of the world’s 993s, but those models require some wiring work and he only plans to launch a product for other markets if he sees the demand.
Also, while this product is ideal for daily driving convenience, it is great for race cars.
I installed an early prototype for a guy who had a 993 race car. He said the lock/unlock thing was a REAL nuisance on the track and over the years they tried (and spent thousands) to defeat the immobilizer to no avail,” said Mingrone. “The funny thing is, with all the effort they made to reduce weight by gutting the 993 interior – there was the lowly immobilizer still strapped in under the dash.
Simple Installation
Installing the IMMO BLOCK in a Porsche 993 is remarkably simple. You pop out the fuel gauge in the dash and behind it, you will find the relay for the door chime. You unplug that relay and in its place, you plug in the IMMO BLOCK. Reinstall the fuel gauge and you are done. Your 993 will no longer engage the automatic immobilizer, but when you lock the car with the key fob, the immobilizer system will still engage as normal.
If you sell the car and want to keep the IMMO BLOCK, you just pop the fuel gauge back out, replace the IMMO BLOCK with the door chime relay and the car is restored to its factory function, complete with the automatic immobilizer system.
If you are tired of having to constantly lock and unlock your Porsche 993, the IMMO BLOCK is the easiest way to prevent the automatic immobilizer without removing the security feature altogether. Best of all, Mingrone offers a 30-day money-back guarantee, so if you somehow don’t like the function, you can return the unit for a full refund.
