danboy

Hi all, i fitted a set of coil packs on a cayenne 3.2 V6 because the porsche computer read missfires and there was damage to on of the pack end pieces. this was about 1 month ago, and all has been great but today the car started missfireing and after a while died on me, checked the coil packs as i could smell an electrical burning smell under the bonnet and the last coil pack (at the back of engine No.6) had litterally burnt out!!! replaced it and now the car will not start?

was wondering if anyone has ever come across this and how you fixed such a problem, im starting to think its fryed the ecu as it does not fire at all!
thanks. dan

mudman2

coils can damage the plugs

ltc

IMHO, plugs should ALWAYS be replaced when damaged (cracked) coils are discovered.

I don't think you "fried" your ECU.
Were you wearing wool pajamas with the little vinyl footies sewn on (and the little flap in the back) when you replaced the coil packs?
(little inside forum humor from our most recent member who "fried" his ECU)

When you say it wont' start, I'm assuming it cranks, the dash/MFD is functional, etc.?

Have you checked ALL your fuses? If you have to ask where they are, the answer is no.

JFScheck

Stupid but it might work - disconnect the battery (positive side is enough) let sit for a few (engage the starter to ensure those Capacitors are drained) then hook it back up and see if it starts?

Kinda a "Hard Reboot" for the ECU...

ltc

I checked with Larry.....

He's pretty sure that engaging the starter with one side of the battery disconnected will do.......

Nothing.

Of course, we are talking about Larry here (he's been unable to walk for a few days now), so caveat emptor.

If you had that oh so wonderful smell of ozone and a coil pack litererally burnt, you'll be lucky if it is nothing but a fuse.

Hey, look on the bright side, the last time a Cayenne had "that funny smell", it was a Hybrid....about 15 seconds before it had a "thermal event" in front of Sr management.....seems like only yesterday.

Slow Guy

A good habit to get into is always disconnect the Neg. side first, then the Pos. side. This way if the wrench accidentally hits metal while you're disconnecting the pos. term nothing will happen. If you touch metal while the Neg. term is still attached you'll get a nice arc/spark/light show and arcing around battery gasses can be very harmful to anything/anyone w/in about 4 ft of it.

Just a good habit to be in.

danboy

found a big fuse was blown under the cover under the bonnet, replaced it, but still no start so tryed a new plug and new coilpack in cyl. 1, and there is no spark??? any ideas?

ltc

Which fuse?
Did you continue to search for others, or just stop after you found this one.

The vehicle should start/run with one plug dead...it will just not run very well, but it will start.

When you say you have no spark on #1, i"m assuming:

A. Spark # 1 was the one that 'burnt' ?
B. Spark 2-5 are all still firing?

danboy

checked all the fuses in the bulkhead area, and all are now good, has no spark on any of the 6 packs?
is there any way of checking that the contol unit is sending out the pulse to the coil packs with a multimeter or something?
thanks.
dan

ltc

No.
Sounds like you're either looking at a new module (and remember, electronics are non returnable) or a trip to a dealer or indy.

You might get lucky and see if PIWIS knows the module is completely dead, however it might still communicate, just the HV section might be gone. Worth a shot however.

Javi Ar

Any body had issues with no spark on their cayenne

mudman2

you need to read the pinned threads