View Full Version : crankshaft sensor values....bad..?525it help
DarkstarEuro
06-06-2009, 06:36 PM
so ive had on going issues w/ this particular 525it 92, since day one, so far in an attempt to first fix an erratic idle.Which turned into a broke on the side of the road problem, i replaced tps, o2, main relay,fuel pump relay, fuel pump, and the dme. Still getting a cranking but not starting engine, so today i went and checked the last 3 things i could think of after insalling the new dme to no avail.Coolant temp sensor, good. Speed sensor good, and the value on the crankshaft position sensor say it should be 1280ohms im getting around 1310, im pretty sure thats out of range, but just wanted to check here and make sure i dont buy another G.D. part i dont need.Also i was wondering if a bad rpm sensor could cause the ecu to malfunction...no fuel or fire.and last but def. not least, die and not start back up again. Thanks for your time.Hope you know something i dont.
janders211
06-06-2009, 06:42 PM
so ive had on going issues w/ this particular 525it 92, since day one, so far in an attempt to first fix an erratic idle.Which turned into a broke on the side of the road problem, i replaced tps, o2, main relay,fuel pump relay, fuel pump, and the dme. Still getting a cranking but not starting engine, so today i went and checked the last 3 things i could think of after insalling the new dme to no avail.Coolant temp sensor, good. Speed sensor good, and the value on the crankshaft position sensor say it should be 1280ohms im getting around 1310, im pretty sure thats out of range, but just wanted to check here and make sure i dont buy another G.D. part i dont need.Also i was wondering if a bad rpm sensor could cause the ecu to malfunction...no fuel or fire.and last but def. not least, die and not start back up again. Thanks for your time.Hope you know something i dont.
1280 t0 1310 is pretty close. Last bad CPS I tested was like 3350000 Ohms...i.e. off by more than 10 fold.
DarkstarEuro
06-06-2009, 07:57 PM
oh yeah and no check engine light, just the trans program.It said check control for about 3 minutes after i put the new ecu in.But thats gone now. There is compression, trans is great besides when the car locks it into 3rd for limp home.I think a wire hunting i must go. Isure hope not.
kakalika
06-06-2009, 08:05 PM
Not to hijack this thread, but why do these CPS's go bad. I mean, there are no moving parts or electronics in them. Just a solid magnet. I don't understand why they fail.
janders211
06-06-2009, 08:37 PM
Not to hijack this thread, but why do these CPS's go bad. I mean, there are no moving parts or electronics in them. Just a solid magnet. I don't understand why they fail.
Most failures can be attributed to cases of near misses with ferrite dense meteorites, coupled with unusual sunspot activity...same reason f-117's go down.
Binjammin
06-06-2009, 11:19 PM
Not to hijack this thread, but why do these CPS's go bad. I mean, there are no moving parts or electronics in them. Just a solid magnet. I don't understand why they fail.
It's a copper winding. Corrosion alone will cause it, or a lot of heat and time too.
kakalika
06-07-2009, 12:25 AM
LOL, you got me there!!
Most failures can be attributed to cases of near misses with ferrite dense meteorites, coupled with unusual sunspot activity...same reason f-117's go down.
yep the hayney says that the resistance will read at 1280 +/- 10%.....
DarkstarEuro
06-07-2009, 03:08 AM
sooo........is my crank sensor bad? Im not too sure what the 1280 at 10% means either.I mean thats what my bentley says too, so i put my multimeter on the setting marked 2000 ohms, which i think is the correct value to test at.
tvcasualty
06-07-2009, 07:54 AM
Plus or minus 10% is what that meant. 10% of 1280 is.... 128. 128 + 1280= 1408. Which means 1310 is within spec,back to the drawing board (un)fortunately.
DarkstarEuro
06-07-2009, 10:52 AM
shit
wait before you do this, the manual says that M50 and M60 are 1280....but the other motors are different....
atl530i
06-07-2009, 12:37 PM
shit
lol, priceless reaction. I would start metering everything you can.
wait before you do this, the manual says that M50 and M60 are 1280....but the other motors are different....
What was wrong with your car? I never did catch the solution.
DarkstarEuro
06-07-2009, 01:23 PM
it is the m50, non vanos, mid 1992 prod.Im testing wires today, get on later and give more info, before i get a hemorrhoid.
ok so i spent the day testing input and output from the dme and this is what i came up w/... Ignition On.....
the fat red positive constant from the battery,i think its labeled as the B+ battery junction. that is in the computer box has 2.5V, that seems wrong, shouldnt it have 12V?
Also terminal #26 in the ecu is battery constant also only has 2.5V.
Terminals #54,#56 run positive 56=11.3/54=.1v.
Terminal #s 34,55,6,28 ground for above good
#8 output check engine, varying ground, does something weird, i tried to check the ground and the meter acted like i had the polarity reversed.
#11 output TPS 9.6V
#13 output MAF .04V
#14 maf ground good
#43 temp sensor ground good
#2 ICV ground good
#3,4,5 injector ground good.
While i was checking these the voltage on the battery constant post dropped from 2.5v to 1.4v.
So im gonna put my battery on a charge and see what happens tomorrow.eeeehhhhh, i was never really proficient at electronic systems before this, so let me know if im doing something wrong, i wish i could say i was over my head,but the local shop here quit returning my calls, so ive obviously gotten farther than they had.
Their computer wouldnt tell them what was wrong so they got scared.:lol
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