A4 Cab deployed airbags, wont start

boomkim1

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hi,

I have recently purchased a 2003 a4 2.5 v6 tdi cabriolet with some light front panel damage, and drivers and passenger airbags deployed. I have attempted to start the car, then engine cranks but doesn't start.

Is it possible to start and engine before the airbags have been replaced? I believe the airbag module will eventually need to be reset/replaced but wondering whether this by itself would stop the car from starting.

When they key is turned to the ON position, the ESP light goes off, then after about 5 seconds, there is a click and the light switched ON again. I have run vagcom and get a fault ' 01318 Control Module for Injection Pump (J399) 49-10 No Communication'

Any ideas ?
 
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There's usually a crash sensor on most cars on the bulkhead with a reset button on the top its there to kill the engine

Not sure if audi uses one or where abouts it is but worth a look
 
cant see that fault being caused by the accident damage. thats a pump control unit fault, nothing to do with crash data being stored in the airbag unit.
 
From what I remember, if the crash is hard enough to trigger the airbags (+5g which then begs the question of why did the airbags go off if it only has light panel damage, airbag activation is very much a last resort and reserved for big, hard impacts) then the cars system automatically cuts off the fuel supply to kill the engine and prevent fuel spills/possible ignition. The easiest way to do this would be to cut power to the injection pump control unit, hence turning the pump itself off.....

This may be your problem (and would tie in with the fault code you are getting), but don't quote me on it.....

If this is correct then once you replace the airbags/crash sensors and reset them, then you should then be able to reset the injection pump control module and start the engine...
 
From what I remember, if the crash is hard enough to trigger the airbags (+5g which then begs the question of why did the airbags go off if it only has light panel damage, airbag activation is very much a last resort and reserved for big, hard impacts) then the cars system automatically cuts off the fuel supply to kill the engine and prevent fuel spills/possible ignition. The easiest way to do this would be to cut power to the injection pump control unit, hence turning the pump itself off.....

This may be your problem (and would tie in with the fault code you are getting), but don't quote me on it.....

If this is correct then once you replace the airbags/crash sensors and reset them, then you should then be able to reset the injection pump control module and start the engine...

I think it is something similar to what you describe. Once the engine starts, the click sound must be the injector pump getting switched off due to the cut off. I shall order an airbag module then try start. The code could also be indicative of a faulty injector pump, but hopefully not.
 
I think it is something similar to what you describe. Once the engine starts, the click sound must be the injector pump getting switched off due to the cut off. I shall order an airbag module then try start. The code could also be indicative of a faulty injector pump, but hopefully not.

Put it this way, the car must have been running to crash in the first place, so its going to be something that has occurred at the time of impact. Surely if the airbags have deployed than the fuel would have been cut of???
 
I shall be removing the existing airbag ECU to verify the part number and ordering a replacement. Is it possible for the car to start without the airbag ECU? Once the airbag ECU is disconnected, I shall check whether the tick occurs and warning light appears.
 
The a4 cab 2.5 tdi has now been lying lifeless on my drive for 2 months. I have replaced all the airbags and changed the airbag ECU (coded it to the car successfully using VCDS).. Then bump started the car, it started, and the engine run for about 5 minutes, not very well, lots of smoke which may be due to lots of easy start, but would not rev. I switched off the engine and cannot get it to start again. The engine just cranks but does not start. I have removed one of the injector lines and no diesel is squirt when cranking. I have checked the fuel pump relay and fuse 28, and they're both working. I have also run an output test on the in tank fuel pump and it runs and pushes diesel to the fuel filter.

It seems that diesel is getting to injector pump but somehow the injector is not functioning correctly (i.e. compressing / squirting the diesel). An engine scan on vcds shows a `Engine Speed Signal for Injection Pump`.

Looks like all the above seems to suggest a fault with the injection pump. Or could it still be a fuel shut off due to the previous crash??

All out of ideas here ... Any ideas much appreciated.
 
iv had many a audi damaged with bags out
never stopped them starting
id be looking at the pump
 
I'd be getting this car plugged in at this stage, we can all 2nd guess but it could be that the chip in the key is damaged or the reader is,

You mean plugged into VCDS? I have the registered version and have used it to code the airbag ecu and test the in tank pump. If so I If it was a the chip in the key, I would think a fault would be seen on VCDS .. along the lines of engine start stopped by immobilizer.. but then again, with the luck I have had with this car, cant rule it out just yet.

I also read that some codes are stored in the injector pump ECU, how can I read this codes.. Would probably give the definitive answer.