Porsche 996 cranks but will not start

Porsche 996 cranks but will not start

Author
Discussion

Paulnico

Original Poster:

12 posts

133 months

Sunday 20th November 2016
quotequote all
Hi, I have a 2001 996 turbo tip. Yesterday I drove a short trip stopped unlocked my centre console glove box, relocked it then the car would not start. I've since had it checked out for fault codes only to fined 4 codes relating to the immobiliser.
P0015 no engine start possible. W lead (dme immobiliser) open circuit.
P0021 no communication with PST 2. This fault is stored if the k-lead is short to ground.
P0021 no passenger compartment monitoring. Interior monitoring sensor fault.
P0030 airbag signal acknowledged. This is triggered log.
None of the codes can be cleared and I don't know the next step.
Originally the car would crank over, fire then die.
Now it cranks over does not fire at all.
Any suggestions please.
Paul.

Edited by Paulnico on Sunday 20th November 19:44

Chlorothalonil

3,619 posts

201 months

Sunday 20th November 2016
quotequote all
Have you tried another key?

Paulnico

Original Poster:

12 posts

133 months

Sunday 20th November 2016
quotequote all
Yes I tried both keys and the same result.
Both keys will lock and unlock doors and activate the alarm.

bgunn

1,417 posts

131 months

Sunday 20th November 2016
quotequote all
P0015 no engine start possible. W lead (dme immobiliser) open circuit.
P0021 no communication with PST 2. This fault is stored if the k-lead is short to ground.

These are stopping it from running. I'd say P0015 is causing P0021 - the engine management is not being powered.

Check your fuses (might even just be an idea to replace all of the engine management ones) and check the engine management relay.

Does the fuel pump prime when you turn the key to 'ignition' (just before start). You should hear a whine from under the front of the car for a couple of seconds when you first turn the key to the position before the starter operates. If not, suspect the wiring to the ECU (or a fuse). If that checks out, suspect the ECU.

Ozone

3,043 posts

187 months

Sunday 20th November 2016
quotequote all
My 986 did this but I didn't know the codes. The petrol pump had seized. Got my trusted mechanic to look at it, he put it on the ramps and hit the bottom of the fuel tank with a mallet and it fired up, idled for 20 seconds then died. New fuel pump sorted it.
I hope you get it sorted.

Paulnico

Original Poster:

12 posts

133 months

Sunday 20th November 2016
quotequote all
I can't hear fuel pump whine, but after cranking for 20 secs it smells of petrol.
I had checked all fuses with multimeter none blown but some feel loose
Are there any relays I need to check, why is the the code reader stating an immobiliser issue?

Edited by Paulnico on Sunday 20th November 21:12

edc

9,234 posts

251 months

Sunday 20th November 2016
quotequote all
Ozone said:
My 986 did this but I didn't know the codes. The petrol pump had seized. Got my trusted mechanic to look at it, he put it on the ramps and hit the bottom of the fuel tank with a mallet and it fired up, idled for 20 seconds then died. New fuel pump sorted it.
I hope you get it sorted.
Echo this on my 986. Plenty of battery power to crank but no start. I checked all the fuses and all ok. My generic code reader didn't pick anything else up ie it won't show immobiliser codes anyway.

silver surfer

480 posts

208 months

Sunday 20th November 2016
quotequote all
Check fuel pump relay.
Does the tacho move on cranking....if no..then check crankshaft sensor.


SS

Paulnico

Original Poster:

12 posts

133 months

Monday 21st November 2016
quotequote all
Rev counter does flicker when cranking, volts drop down to 10v even with slave battery fitted.

Paulnico

Original Poster:

12 posts

133 months

Thursday 24th November 2016
quotequote all
Still need help if anyone has more suggestions please

Paulnico

Original Poster:

12 posts

133 months

Thursday 24th November 2016
quotequote all
Still need help if anyone has more suggestions please

bgunn

1,417 posts

131 months

Thursday 24th November 2016
quotequote all
It's not going to go with that immobiliser code.

You need to fix that.

Paulnico

Original Poster:

12 posts

133 months

Thursday 24th November 2016
quotequote all
Do I need to take it to main dealer? Any suggestion I'm in north east Middlesbrough area?

CarreraLightweightRacing

2,011 posts

209 months

Thursday 24th November 2016
quotequote all
Hi OP, open a thread in the 996 section of the 911uk.com forum. There is a guy there username Demort. He is a wonderful source of information and incredibly helpful, I'm sure given the codes you mention he will be able to help you further.

bgunn

1,417 posts

131 months

Thursday 24th November 2016
quotequote all
Not necessarily a dealer, as they'll charge you the king's shilling. A good auto electrician with access to diagnostics equipment.

I'd help, as I have PIWIS and the wiring diagrams, but unfortunately you're at the other end of the country..

A thorough work through of the engine management wiring, making sure it has power and good earths, and then troubleshoot why it's not seeing the immobiliser code (failed wiring, failed transponder/ecu or otherwise).

88racing

1,748 posts

156 months

Thursday 24th November 2016
quotequote all
Any dampness under the left seat? That's where the security ECU lives...

Paulnico

Original Poster:

12 posts

133 months

Friday 25th November 2016
quotequote all
Just had time to check today, and no damp under the seats, I changed all fuses relating to alarm, I checked voltage and that seems ok 12.5v. When I turn the ignition on I can hear the pump spin up the stop, after a couple of long cranks on the starter I can smell fuel I'm the exhaust but no sign of life.
I've found a local independent but he wouldn't impart any information other than £70 to look at the car, even when I told him all the symptoms and the codes, he would not suggest what it could be or any costs ranges,

Pope

2,636 posts

247 months

Saturday 26th November 2016
quotequote all
Generally I have had really simple breakdowns as you describe with weird (unexplained) causes...

As you have the codes and any recurrent ones will still be there after maybe try these two simple things first?

Disconnect the battery - as it's a 996; ensure ignition on beforehand. Reconnect and retry.

Next - if it still doesn't go! - remove the fuel pump relay (look up above the fuse board; the grey relay with the pink text on it is the one) attempt start with throttle fully open.

The local shopping centre car park had a habit of causing unexplained non-starts (9x6 specifically) we put it down to security tag readers/cancellers after owners described placing keys/wallets on cashier desks.......

A few short starts - especially during warm up can flood the engine - doesn't initially explain the codes but worth a go.....

On a third note I have had 9x6 suffer a strange issue with tappets (either over or under filling) resulting in a weird lack of compression - continued attempts at starting eventually has the thing up and running (accompanied with a cloud of smoke and tappet noise for the next few minutes - and no repeat afterwards).

If still no go - and maybe worth checking beforehand?! Does the ignition switch action feel right? 9x6 switches are known to break up and cause electrical issues...

Worth a go; if no luck at least the above are tests you won't get charged for.....

Edited by Pope on Sunday 27th November 00:02

Paulnico

Original Poster:

12 posts

133 months

Sunday 27th November 2016
quotequote all
Good points, I tried them this morning, I removed the battery to clean water and stuff from the drain bungs, noticed the alarm unit had corrosion on all of the terminals, cleaned this with contact cleaner and fine sand paper, refitted batter, cranked engine for 10-15 seconds no fire, removed fuel pump relay crancked 2 x 10 seconds not a flicker.

But reading your other note regarding the shopping centre car park, when I stopped the car last, as stated I opened centre console, I then replaced the key and thought I would check the oil level, I was going through the process sitting on the level part of the drive out side of my house, "This is a shared drive entrance" my neighbour turned up so I opened the gates to my drive with a remote controller, went to start the car that's when it would not start, could my gate remote have effected the immobiliser?

mickthemechanic

326 posts

106 months

Sunday 27th November 2016
quotequote all
Hi

Are any warning lights not illuminating when the ignition is turned on that normally are like engine management. If there is a power interruption to the engine management fuse/relay often there will be no warning light lit as the system is dead. Also from your o/p you say you opened and closed glove box is there a light in there and if so is it still working.