Immobiliser problem? - 2.7 Boxster 2003

[PigMi]

Hi,

Im building a Porsche powered Classic mini and I am having problems with starting the engine. The problem actually started on the donor vehicle as the last time I tried to move it under its own power it would start and stupidly I put it down to old fuel/spark plugs etc...

Im now at a stage where the whole wiring loom is in the mini as well as pretty much all the modules being attached. We have attached the OBD and it didn't show any problems, the key is being read, the M534 is communicating with the key, but we do not have the spark or fuel pump.

I took the ECU to one person I know, but he was unable to reprogram it and then a friend who is knowledgeable with ECU's has tried to bypass directly in the ECU the immobiliser but this hasn't changed anything, the engine cranks over without a problem but no spark or fuel.

My question is that I have read that there are a lot of problems with the M534, is this probably the case to? Or are there any other failsafes that stop the ignition and fuel?

Any help would be much appreciated!

[Smallblock454]

If the systems works properly, the starter motor won't turn over when the immobilizer system is activated.

So for example, if the transponder isn't learned to the car, nothing happens if you try to start the engine.

What DME is used? 7.8?

[PigMi]

Originally Posted by Smallblock454

If the systems works properly, the starter motor won't turn over when the immobilizer system is activated.

So for example, if the transponder isn't learned to the car, nothing happens if you try to start the engine.

What DME is used? 5.2.2?

Please understand that my knowledge on the electronics side is limited. From what my friends who have been helping me have explained to me, The key is being read and the immobiliser recognises it, it seems to be more the communication between the m534 and the ecu.

The DME is a 7.8 if I remember

[PigMi]

Originally Posted by Smallblock454

If the systems works properly, the starter motor won't turn over when the immobilizer system is activated.

So for example, if the transponder isn't learned to the car, nothing happens if you try to start the engine.

What DME is used? 5.2.2?

Please understand that my knowledge on the electronics side is limited. From what my friends who have been helping me have explained to me, The key is being read and the immobiliser recognises it, it seems to be more the communication between the m534 and the ecu.

The DME is a 7.8 if I remember

[Smallblock454]

You can't deactivate the immobilizer in a Porsche DME 7.8 via software. If you try, you'll brick the DME. This Porsche system is proprietary.

From my experience in general the M534 doensn't break without an event. It can break while connecting the starter battery while ignition is on and some other events like this.

But when the M534 breaks, the DME doesn't allow the starter to crank and ignition and fuel injection is turned off. So i suspect you have a problem related to the DME or the wiring harness / sensors.

[PigMi]

Originally Posted by Smallblock454

You can't deactivate the immobilizer in a Porsche DME 7.8 via software. If you try, you'll brick the DME. This Porsche system is proprietary.

From my experience in general the M534 doensn't break without an event. It can break while connecting the starter battery while ignition is on and some other events like this.

But when the M534 breaks, the DME doesn't allow the starter to crank and ignition and fuel injection is turned off. So i suspect you have a problem related to the DME or the wiring harness / sensors.

Thank you for this, I will keep searching for the problem. It is strange as the engine cranks, but the fuel pump doesnt run and there is no spark.

[997_986]

This article describes something else, butr you could try to force the fuel pump running by bypassing the relais contacts with a jumper wire, figure 2. If it turns on you can rule out the pump itself.

[PigMi]

Originally Posted by 997_986

This article describes something else, butr you could try to force the fuel pump running by bypassing the relais contacts with a jumper wire, figure 2. If it turns on you can rule out the pump itself.

Thank you for the reply, unluckily I have already tried this and the pump runs fine, really strange situation.

[mikefocke]

There is no sound after the key is turned (or simulated)?

[Beelzy]

Originally Posted by PigMi

Thank you for this, I will keep searching for the problem. It is strange as the engine cranks, but the fuel pump doesnt run and there is no spark.

Classic DME symptom.