Crank but no fire ***SOLVED***

[Ahsai]

Interesting. What's the pin number of that 2v pin?

[txhokie4life]

13 hours ago, Ahsai said:

Interesting. What's the pin number of that 2v pin?

 

 

Luted as EXP Cutoff, DME pin 12.  I'm probing X3/1 - pin 6, GN/OR goes to M126 CU Airbag

Which either goes to module M562 Control Unit Airbag pin 24 Crash Output

or M563 Control Unit M R S pin 34 Crash Output

 

It suggests this is coming from the immobilizer?  I'll need to double check if mine is plugged in on the race car at this moment. (In theory its not 

needed because I have had the DME re-coded not to need the immobilizer.)  I'm at the house now -- headed to shop later.

 

However, that said, I had the set sent off and confirmed it would start another car before the modification (and after the no-start issues).

 

I'm not at the point of hacking the good cars wiring harness yet to disconnect this signal to see what happens (but I'm getting close ?

 

Mike

 

[txhokie4life]

6 hours ago, txhokie4life said:

 

 

Luted as EXP Cutoff, DME pin 12.  I'm probing X3/1 - pin 6, GN/OR goes to M126 CU Airbag

Which either goes to module M562 Control Unit Airbag pin 24 Crash Output

or M563 Control Unit M R S pin 34 Crash Output

 

It suggests this is coming from the immobilizer?  I'll need to double check if mine is plugged in on the race car at this moment. (In theory its not 

needed because I have had the DME re-coded not to need the immobilizer.)  I'm at the house now -- headed to shop later.

 

However, that said, I had the set sent off and confirmed it would start another car before the modification (and after the no-start issues).

 

I'm not at the point of hacking the good cars wiring harness yet to disconnect this signal to see what happens (but I'm getting close ?

 

Mike

 

 

 

 

Cut the Crash wire on the running car 

12v one side, 240mv other

 

car started...

 

so so that has no affect !!!

 

the search continues

[Ahsai]

What about transplanting the immo and the DME from the street car to your race car?

 

Also back to the CPS signal, I still wonder if the p-to-p value is too low. Can you check the CPS signal of the street car at the dme for comparison also?

[txhokie4life]

Hooked up my durametruc

can access both dmes On their respective cars.

 

on race car all my live data looks like defaults and voltage is 0v

 

on the street car I get real values and 12v for voltage.

 

i was short on time and didn’t think to swap DMEs, will do that next time

 

plan to probe each dme pin values as well

 

might not be able to see cps on street car because I’d have to hack up ability to run starter without dme (which I don’t think can happen without mods)... will add it to the list of possibles.

 

 

[txhokie4life]

The rain, the battery running down, battery cables, kill switches, fuses, relays, DME, Immobilizer, Key RFID, etc

None of that had anything to do with it

Shortly after I bought the car
I installed a traqmate system, including a traqmate USB to control the cameras and data acquisition.

That system had been in the car for nearly a year prior including 2 or 3 event weekends with no symptoms whatsoever.

There was a pin on the traqmate usb labeled 5v with the input analog pins.  The documentation. Is poor, so I hooked up 5v off the obdii port after having found you can get 5v off of there (I don't remember how that was determined, probably internet)
 

I eventually had to buy a street car to have a known good reference.  She showed up late last week and was keen to success.

 

After checking things back and forth between the street car and the Spec Boxster, including triple checking the DME.

I decided some input to the DME must be wrong and is causing the DME not to let the car start.

 

So I wrote out all 88 pins and made a chart and one by one probed each signal in the street car, and then did the same in the spec boxster.

After probing all the signals between the street car and spb I noticed only a couple differences, one was the software voltage pin which only

connects to the obdii port.
Street car was 0v, spb 5v.  Also the durametric could talk to both dmes, but on the spb, all live data was defaults and voltage was 0v, regardless of the DME,

while on the street car with both DMEs I got live data.

I went home and thought about where the 5v could have come from, and I remembered the traqmate usb had a 5v pin.

I also remember sourcing that 5v from the OBDII connector as that is what I had found online to do.  My spidy senses

were tingling -- was I on to something?

About midnight last night, I found some documentation online on the old traqmate system.  It wasn't very good, but I could see a photo of the pins labeled on the USB box

and blew up the picture. , It wasn't clear, but it looked like 5v was an output
Not an input!!!  I had figured at the time that the 5v was needed for the analog data acquisition, not the other way around.  Surely it couldn't be that simple.

After a sleepless night 
I ran out to the shop this morning, unconnected the traqmate usb
And she fired right up
Motherf@cker!!!

I think the 5v put the dme into some sort of program mode or something, disabling its ability to start the car.

Why did jumping it work without battery?

I think once you got 14v, the 5v wasn't high enough to put it in the program mode...
I also think that once you get running, the DME just does its thing -- OR, the Boxster's alternator put out 14v, and once again

the 5v input was read as a low, not an assert.

 

Further complicating the matter was the small fuse box that was added for accessories that I had tapped off of for the traqmate 12v hookup

is janky, and I don't think it has a good internal connection.  That's getting yanked and a new, and more accessible unit will be installed.

Just diabolical....

Now I have to put it all back together and get my medical done and sign up for NOLA.
 

Thank you very much to all who supported my efforts and responded to my posts -- especially Ahsai.  If nothing else,

the moral support allowed me to just keep plodding along.

 

 

[Ahsai]

Congrats! I would not have figured it out for sure haha

[Ahsai]

Btw, I think you just invented a perfect anti-theft technique ? Even if someone swaps in their own immo and DME, still won't get the engine to fire.

[txhokie4life]

If you see me running around with a bunch of 9v batteries in OBDII bundles just before race grid -- LOL

[Ahsai]

LOL

[txhokie4life]

Thanks to all those who helped!

 

NOLA Motorsports bound tomorrow morning.

 

I’m stoked and nervous, but most of all relieved I can hit the track thx to everyone’s help!

 

cheers,

 

Mike

[Ahsai]

Looks like it's all ready for the track!