Immobilizer bypass, step by step with photos

I installed the bypass product by Specialized ECU Repair yesterday.

My reasoning is simply to alleviate any future electronic headaches that I can. The product is $875, not cheap, but worth it to me.

My stock system works perfectly at the moment, but who knows as these systems age.

1) remove leather cover on firewall behind drivers seat.
You will now see two metal covered boxes. Left one is hold, right one is silver. Both must be removed.

2) drill out all rivets holding these boxes together. This is the most time consuming part. There are about 8 rivets per box.

3) in the smaller gold box on the left unplug the stock electronic box and replace it with the new product you've purchased. You're now done with this box and can reattach it to the firewall.

4) in the larger silver colored box on the right, you will simply cut two wires from the harness and join them with a wire nut. The instruction manual that comes with the product clearly tells you which ones. You will also cover the other side of the wires you just cut with electrical tape.

5) test that you can now start the car without pressing the fob button.

6) reattach silver box to firewall and you're done.

Totally simple and it works.
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Thanks for posting. I assume you can still use the FOB to lock and unlock the doors. All this does is keep you from having to press the button every time you want to start the car. Does the car keep any alarm features?

 

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Exactly

 

Hi Skipp - thanks for posting this

 

Nice job, thanks for sharing.

 

This might come in handy...thanks!

 

Wow. Very cool and still much cheaper and less of a headache than buying a new immobilizer, fobs and paying for codes that don't work.

 

I spoke with the owner this morning - very nice guy.

Something to point out:

96/97 355's, the immobilizer cuts power to the starter, 98's and up it does not.

That said, for 98's and up, the jumper wire (cutting of wires) may not be required. George told me this can be tested first and if it does not work, then that step should be carried out.

 

Wish I had know that before cutting the wires, since I have a 98.

Anyway, if that's true, you would only need to drill the rivets for the gold box on the left. That would truly be " plug in play", since you're simply swapping the module in the gold box on the left with the new product.

 

Jorge was not aware of the model differences until I told him. The starter relay is controlled within the one box, hence the need to jump it. So, that may not need to be done on cars in which the starter cranks when immobilizer is active.

 

Great info, thanks for posting!

 

How do we just get rid of that whole mess? I would love to have that immobilizer just gone.

Besides buying a 1995, how do we just pull the whole thing out?

 

You would need to trace every circuit the immobilizer kills. That assumes it's done out side of the main ECU and I think that is not the case which is way this box is needed.

 

very informative thread

 

Once again, Dave... your knowledge is a benefit to us all. ('98 owner here)

 

To update:

Car starts fine with the immibilizer bypassed. However, the red light on the dash stays blinking while driving. I haven't talked to Jorge about it yet. Any body here have any thoughts ?

 

Are you talked about the LED in the center vent?

 

Yes Dave. Stays flashing on when driving. Any thoughts ?

 

Did the instructions say anything about disconnecting the battery before starting the modification and then reconnecting it once complete?

If not, I am thinking that you may need to re-boot the system by disconnecting and reconnecting the battery in order to get rid of the red flashing light. Maybe also clear the system codes with a hard reset by touching the +/- leads together with them disconnected from the battery.

Disconnecting the battery before doing any work on a modern car is usually good advice anyway.
Alden

 

The new bypass box lets everything run even though the immobilizer is set to immobilize. When in this state the light blinks. If you pushed your fob right now the immobilizer would think it is in mobilize/run mode and the light would go out. Then next time the immobilizer sets itself the light will flash again just as it was intended to do.
The box bypasses the function and lets the car run but the immobilizer itself still thinks it is operating the same.

You are replacing the interface between the immobilizer and the car. The new box minicks that a run condition is present even though it is not. The immobilizer (and alarm) is still there trying to do what it was meant to do, hense the light functions just as it should.

Live with it blinking or pull out the vent and snip the wires. I don't thing you have any other options.