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M3 REV COUNTER STOPPED WORKIN....?
Posted: Tue Dec 27, 2005 7:26 pm
by Cov
JUST WONDERING IF ANYONE COULD TELL WHERE THE PICK UP FOR THE REV COUNTER IS ON MY M3 EVOII, JUST DIDN'T WORK THIS MORNING WHEN I STARTED IT, ANY HELP WOULD BR GREAT THANKS. 
Posted: Tue Dec 27, 2005 8:43 pm
by karlp
works off the ecu.
Karl
Posted: Wed Dec 28, 2005 11:17 am
by Demlotcrew
karlp wrote:works off the ecu.
Karl
Are you sure?
Andrew
Posted: Wed Dec 28, 2005 12:21 pm
by karlp
To be precise.
An engine speed sensor on the bellhousing feeds a signal to the ECU - the ECU then sends a signal to the rev counter.
Karl
Posted: Wed Dec 28, 2005 2:41 pm
by Demlotcrew
Yup thats correct, but there is no direct feed from the ECU which you can see if one were to take a look at the ECU.
Andrew
Posted: Wed Dec 28, 2005 4:21 pm
by karlp
On my diagrams pin 21 from the ecu goes to tachometer and fuel economy gauge.
karl
Posted: Wed Dec 28, 2005 6:29 pm
by herman
Could be re-chargeble cell in the cluster
Posted: Wed Dec 28, 2005 6:58 pm
by Brianmoooore
Poor connection at pin 9 (black wire) of the C101 connector is often the cause of no tacho on an E30.
Don't have any M3 diagrams handy, but would expect this to be the same on a M3.
Posted: Thu Dec 29, 2005 9:05 am
by jpboost
Brian,
Is the C101 connector the ECU end or the clock end?
Cheers
Posted: Thu Dec 29, 2005 10:03 am
by Brianmoooore
jpboost wrote:Brian,
Is the C101 connector the ECU end or the clock end?
Cheers
About half way between. It's the twenty something pin plug and socket clipped to the engine bulkhead just inboard of the fusebox, where the engine loom connects to the body looms.
I'm assuming that the M3 is similar to other E30s in this area.
Posted: Thu Dec 29, 2005 10:38 am
by Demlotcrew
Yup its the same, but it has a few extra feeds.
Andrew
Posted: Thu Dec 29, 2005 12:55 pm
by jpboost
cheers.
my tacho hasn't worked since I got the car, keep meanign to get around to do some investigating. at least I now know where to start.
thanks again
Posted: Thu Dec 29, 2005 1:18 pm
by toptints
howdy. My rev counter stopped working on my 325i and it turned out to be a short circuit in the boot which was down to the boot light. Every time i used to open my boot it used to blow a fuse, which runns the same circuit as the rev counter, so check your fuses. If it is blown, it could be down to a short circuit on one of your lights.. ie: glove box, interior or boot etc.. A BMW specialist in Gloucester found the fault on mine. Good Luck.
Posted: Fri Dec 30, 2005 6:06 pm
by Cov
THANKS A MILLION LADS SHOULD BE ABLE TO GET IT SORTED FROM ALL YOUR INFO, THANKS AGAIN.
Posted: Fri Dec 30, 2005 6:29 pm
by Dan318-is
toptints wrote:howdy. My rev counter stopped working on my 325i and it turned out to be a short circuit in the boot which was down to the boot light. Every time i used to open my boot it used to blow a fuse, which runns the same circuit as the rev counter, so check your fuses. If it is blown, it could be down to a short circuit on one of your lights.. ie: glove box, interior or boot etc.. A BMW specialist in Gloucester found the fault on mine. Good Luck.
the renowned fuse 21
bastad thing!