996TT Won't Crank
Discussion
Tried to start my 996 last weekend after a period of criminal lack of use, only to find that I'd forgotten to plug the trickle charger in so I got the familiar clicking from the starter and not much else. I plugged the charger in and left it alone all week.
Back to the car today and it won't crank at all... the battery isn't the problem - I've tried another battery and a jump start pack but the car won't start:
- Electrics all work fine
- Dash lights up as expected, headlights work and level themselves when ignition turned on
- Turn the key the final step and nothing more happens. Starter doesn't turn/engage, car doesn't crank, just... well nothing!
Google suggests the clutch switch, but I don't have one, this seems to be a US/some other markets feature. The ignition switch is also mentioned as a potential cause - mine feels fine but I haven't tested beyond a good wiggle.
I plugged my ODB scanner in and no faults registered.
A semi-random approach didn't find any blown fuses. Starter relay perhaps (behind rear seats apparently), not checked yet.
Anybody had the same? Any other suggestions?
Back to the car today and it won't crank at all... the battery isn't the problem - I've tried another battery and a jump start pack but the car won't start:
- Electrics all work fine
- Dash lights up as expected, headlights work and level themselves when ignition turned on
- Turn the key the final step and nothing more happens. Starter doesn't turn/engage, car doesn't crank, just... well nothing!
Google suggests the clutch switch, but I don't have one, this seems to be a US/some other markets feature. The ignition switch is also mentioned as a potential cause - mine feels fine but I haven't tested beyond a good wiggle.
I plugged my ODB scanner in and no faults registered.
A semi-random approach didn't find any blown fuses. Starter relay perhaps (behind rear seats apparently), not checked yet.
Anybody had the same? Any other suggestions?
It depends on the failure mode of the unit. It can be faulty but appear ok on a scan. First port of call as you know is to see if you get 12v onto the starter relay coil and go from there. Do you have access to wiring diagrams?
My thinking on it being the immobiliser is they cover two circuits and one is usually the starter.
What OBD tool are you using if you don’t mind me asking?
Edit to add you can feel the relay energise if you put your finger on top of it and try and start the car. It could be something as simple as a rubber ducked relay.
My thinking on it being the immobiliser is they cover two circuits and one is usually the starter.
What OBD tool are you using if you don’t mind me asking?
Edit to add you can feel the relay energise if you put your finger on top of it and try and start the car. It could be something as simple as a rubber ducked relay.
Sounds like an immobiliser issue. Mine spends all the winter months tucked away on a trickle charger, and prior to getting one I had to deal with a dead battery on a regular occurrence. If it doesn't even manage to try the starter (really flat )you get very strange behaviour, doors locking and unlocking, spoiler going up and down, and the sounds of all sorts of groaning, plus the alarm going off!!
Quick Update... smells like an alarm/immobiliser issue.
I was using a rubbish OBD reader... having just plugged in an Autel MaxiDiag MD805 I get the following errors logged from the alarm unit:
33 - Passenger compartment monitoring sensor
46 - Central locking synchronisation
54 - Radio receiver faulty
59 - Central locking limit position Secure not reached
60 - Central locking limit position Lock not reached
61 - Central locking limit position Unlock not reached
No faults logged on anything else.
Central locking seems to be working fine, locks/unlocks using either keyfob.
What may be related is that I've recently had two new keyfobs supplied and coded to the car... both were working fine up until now.
I was using a rubbish OBD reader... having just plugged in an Autel MaxiDiag MD805 I get the following errors logged from the alarm unit:
33 - Passenger compartment monitoring sensor
46 - Central locking synchronisation
54 - Radio receiver faulty
59 - Central locking limit position Secure not reached
60 - Central locking limit position Lock not reached
61 - Central locking limit position Unlock not reached
No faults logged on anything else.
Central locking seems to be working fine, locks/unlocks using either keyfob.
What may be related is that I've recently had two new keyfobs supplied and coded to the car... both were working fine up until now.
None of those codes would be related to your problem. If the immobilizer had engaged, it would give an appropriate code in the DME and Alarm Module. The codes you have relate to the central locking system (likely a faulty door lock) and interior monitoring sensor. They might have been in there for a long time.
The immobilizer inhibits the ignition, fuel pump, and starter. Can you hear the sound of the fuel pump priming when you switch on the ignition?
The immobilizer inhibits the ignition, fuel pump, and starter. Can you hear the sound of the fuel pump priming when you switch on the ignition?
Richard Hamilton said:
None of those codes would be related to your problem. If the immobilizer had engaged, it would give an appropriate code in the DME and Alarm Module. The codes you have relate to the central locking system (likely a faulty door lock) and interior monitoring sensor. They might have been in there for a long time.
The immobilizer inhibits the ignition, fuel pump, and starter. Can you hear the sound of the fuel pump priming when you switch on the ignition?
Cheers RH. The immobilizer inhibits the ignition, fuel pump, and starter. Can you hear the sound of the fuel pump priming when you switch on the ignition?
Having investigated those codes and also mentioned them to my Porsche tech it does look like they aren't the cause.
I can't hear the fuel pump prime. All I get on the ignition switch is dash lights and headlights leveling themselves.
Been a while... not had chance to do much about this and my tech is busy moving workshops. Anyway, couple of weeks ago he hooked up PIWIS and confirmed no immobiliser issue (nor anything else reported) and also checked power to the starter relay. Finally today I got the car onto axle stands. Problem is immediately obvious - wire from solenoid to starter has corroded to pretty much nothing, right at the point it enters the starter housing.
Getting permanent +12V to the solenoid and +12V out of it on the key. Tried to improvise a connection but can't get easy enough access to bodge anything temporary with it in situ.
I suspect it will be an recovery or push start to my tech next week when he can fit me in, not sure I fancy another couple of hours on my back on a cold driveway! Depending on any other internal damage/wear to the motor hopefully it might be repair/refurb at less than the cost of a new starter.
Getting permanent +12V to the solenoid and +12V out of it on the key. Tried to improvise a connection but can't get easy enough access to bodge anything temporary with it in situ.
I suspect it will be an recovery or push start to my tech next week when he can fit me in, not sure I fancy another couple of hours on my back on a cold driveway! Depending on any other internal damage/wear to the motor hopefully it might be repair/refurb at less than the cost of a new starter.
UpTheIron said:
Tried to start my 996 last weekend after a period of criminal lack of use, only to find that I'd forgotten to plug the trickle charger in so I got the familiar clicking from the starter and not much else. I plugged the charger in and left it alone all week.
Back to the car today and it won't crank at all... the battery isn't the problem - I've tried another battery and a jump start pack but the car won't start:
- Electrics all work fine
- Dash lights up as expected, headlights work and level themselves when ignition turned on
- Turn the key the final step and nothing more happens. Starter doesn't turn/engage, car doesn't crank, just... well nothing!
Google suggests the clutch switch, but I don't have one, this seems to be a US/some other markets feature. The ignition switch is also mentioned as a potential cause - mine feels fine but I haven't tested beyond a good wiggle.
I plugged my ODB scanner in and no faults registered.
A semi-random approach didn't find any blown fuses. Starter relay perhaps (behind rear seats apparently), not checked yet.
Anybody had the same? Any other suggestions?
Is the car tiptronic or manual?Back to the car today and it won't crank at all... the battery isn't the problem - I've tried another battery and a jump start pack but the car won't start:
- Electrics all work fine
- Dash lights up as expected, headlights work and level themselves when ignition turned on
- Turn the key the final step and nothing more happens. Starter doesn't turn/engage, car doesn't crank, just... well nothing!
Google suggests the clutch switch, but I don't have one, this seems to be a US/some other markets feature. The ignition switch is also mentioned as a potential cause - mine feels fine but I haven't tested beyond a good wiggle.
I plugged my ODB scanner in and no faults registered.
A semi-random approach didn't find any blown fuses. Starter relay perhaps (behind rear seats apparently), not checked yet.
Anybody had the same? Any other suggestions?
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