G/box: 70 Auto: - AAAGH! Car won't start. PNP switch?

thetroublemaker · May 4th, 2013, 16:07

Hi -

Help! My V70 TDI has decided to stop starting as it were.

The symptoms are as of this morning the car didnt start first time - it started, stalled then wouldnt start for about 10 seconds. I left it then retried - fine.

I then drove the car for about 10 miles today and when i went to restart it wouldnt start. Again left for 5 mins it started. So drove home, getting a fuel filter on the way, and left it running with the better half in the car.

got back home, changed the fuel filter it started first time run for about 15 seconds then as soon as i touched the transmission it stalled. Also it wouldnt then even pressing the shiftlock bypass button down come out of park very odd.

The car was driving when it started perfectly with full gearbox function.

Now it wont start and the orange arrow i note is on while i crank the car. Does this sound like a faulty PNP switch?

HELP!!!!

Luxobarge · May 4th, 2013, 18:26

Sounds like possible PNP switch to me - try running the gearlever rapidly back and forth through the gears (engine off) to see if it clears it. If it does, then that's the problem and it'll need dismantling to clean/sort properly.

Just a thought!

Cheers

TurboZutek · May 5th, 2013, 07:26

The PNP switch will disable the starter while the car is in anything but P or N. If the car cranks at all it's unlikely to be the PNP switch causing your engine problems.

The PNP could certainly have an issue (hence the orange arrow) and checking the codes will help in that regard, but it won't make a running car stop and shouldn't contribute to erratic engine conditions.

Chris...

thetroublemaker · May 5th, 2013, 10:09

Cheers - I think we had a "false negative" result there as I had some air in the diesel when restarting.

So my thoughts now are either Air in Diesel getting in through one of the underbonnet fuel hoses, or fuel pump belt timing has moved/slipped.

thetroublemaker · May 6th, 2013, 22:29

bit of an update -

The filter change was a false negative as the air was in the system. I got all the air out the car finally by means of filling the filter fully by undoing the bleed screw and filling it with diesel via a small funnel. So it may well have been the filter that needed changing all along.

this improved things - i.e. it was starting first time - also at the same time I had read some things about the "fuel pump relay" which is apparantly a potential issue on these - although I feel actually this may be referring to the red relay that goes on the petrol models - the TDI not having a lift pump.

anyhoo - I looked under the "main fuses" box and swapped the "Glow Plug" and "Main Engine Control" blue relays over and the engine seems to instantly be starting better. This may be a placebo or it may mean my relay was a bit weak. Either way i will keep an eye on things.

May 4th, 2013, 16:07	#1
thetroublemaker Senior Member Last Online: Feb 20th, 2019 18:16 Join Date: Apr 2006 Location: mk	AAAGH! Car won't start. PNP switch? Hi - Help! My V70 TDI has decided to stop starting as it were. The symptoms are as of this morning the car didnt start first time - it started, stalled then wouldnt start for about 10 seconds. I left it then retried - fine. I then drove the car for about 10 miles today and when i went to restart it wouldnt start. Again left for 5 mins it started. So drove home, getting a fuel filter on the way, and left it running with the better half in the car. got back home, changed the fuel filter it started first time run for about 15 seconds then as soon as i touched the transmission it stalled. Also it wouldnt then even pressing the shiftlock bypass button down come out of park very odd. The car was driving when it started perfectly with full gearbox function. Now it wont start and the orange arrow i note is on while i crank the car. Does this sound like a faulty PNP switch? HELP!!!! __________________ 1999 C70 T5 GT ME7

May 4th, 2013, 18:26	#2
Luxobarge Premier Member Last Online: Apr 26th, 2024 09:37 Join Date: Jan 2011 Location: Horne (Nr. Horley)	Sounds like possible PNP switch to me - try running the gearlever rapidly back and forth through the gears (engine off) to see if it clears it. If it does, then that's the problem and it'll need dismantling to clean/sort properly. Just a thought! Cheers __________________ Some people are like Slinkies, they serve no useful purpose but they still bring a smile to your face when you push them downstairs.

May 5th, 2013, 07:26	#3
TurboZutek Premier Member Last Online: Jan 3rd, 2020 00:42 Join Date: Dec 2009 Location: NB, Canada	The PNP switch will disable the starter while the car is in anything but P or N. If the car cranks at all it's unlikely to be the PNP switch causing your engine problems. The PNP could certainly have an issue (hence the orange arrow) and checking the codes will help in that regard, but it won't make a running car stop and shouldn't contribute to erratic engine conditions. Chris... __________________ Sealed For Life Transmission: "The unit is sealed until it dies from dirty, old fluid which should have been replaced."

May 5th, 2013, 10:09	#4
thetroublemaker Senior Member Last Online: Feb 20th, 2019 18:16 Join Date: Apr 2006 Location: mk	Cheers - I think we had a "false negative" result there as I had some air in the diesel when restarting. So my thoughts now are either Air in Diesel getting in through one of the underbonnet fuel hoses, or fuel pump belt timing has moved/slipped. __________________ 1999 C70 T5 GT ME7

May 6th, 2013, 22:29	#5
thetroublemaker Senior Member Last Online: Feb 20th, 2019 18:16 Join Date: Apr 2006 Location: mk	bit of an update - The filter change was a false negative as the air was in the system. I got all the air out the car finally by means of filling the filter fully by undoing the bleed screw and filling it with diesel via a small funnel. So it may well have been the filter that needed changing all along. this improved things - i.e. it was starting first time - also at the same time I had read some things about the "fuel pump relay" which is apparantly a potential issue on these - although I feel actually this may be referring to the red relay that goes on the petrol models - the TDI not having a lift pump. anyhoo - I looked under the "main fuses" box and swapped the "Glow Plug" and "Main Engine Control" blue relays over and the engine seems to instantly be starting better. This may be a placebo or it may mean my relay was a bit weak. Either way i will keep an eye on things. __________________ 1999 C70 T5 GT ME7

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