signals spiking - but not conected

brett_32i · Post by **brett_32i** » Sat Mar 02, 2013 6:54 pm

attached shows the speed sensor spike to 400k's, and battery drop to 0. there is also another spot in log that you can see speed read 4 k's and a slight dip in battery.

Thing is, speed sensor is not connected. it is trimmed at plug with heat shrink around it.
should i ground it???

Matt · Post by **Matt** » Mon Mar 04, 2013 11:36 am

Looks like a electrical glitch of some sort which is quite strange. It might be picking up occasional noise. Usually the speed sensor comes from the dash speedo unit. If you are not using the signal perhaps cut and insulate the wire at the ECU plug

brett_32i · Post by **brett_32i** » Tue Mar 05, 2013 7:38 pm

thats exactly where it is terminated. about 10mm out of ecu with tape on it.
wondering if i should ground it?

Matt · Post by **Matt** » Wed Mar 06, 2013 6:50 pm

Try that out and see how it goes

brett_32i · Post by **brett_32i** » Fri Mar 29, 2013 12:08 pm

well i installed another loom to see if that would take care of some of these odd signals, but it didnt.

the attached log is probably one of the best, it shows a few good pulls, and the odd signal issue.

@ 1:30.4 the air con, nuetral, start, and tps indicators all flash on, but none are connected? this is the one that seems most odd, as they are just on/off signals, not signal or high speed that you could understand being sensitive to noise.
@ 1:19.6 afm drops to 1.5v in the middle of a pull, but it doesnt look like the pull was effected (load and rpm still increased)
@ 1:55.4 TP spikes to 255.
@ 0:52 it doesnt read anything, this happens a lot.

this run didnt have the speed sensor spiking, but one of my other logs does still show it spiking.

Is this common? am i worried about nothing? or does my vehicle have issues?

brett_32i · Post by **brett_32i** » Fri Mar 29, 2013 12:11 pm

ok, i took a snap shot of the log with the speed sensor spiking.
consult view shows the neutral switch flashing on at exactly the same time? (again, neither are connected, removed from loom)

brett_32i · Post by **brett_32i** » Fri Mar 29, 2013 12:16 pm

and another one showing speed spike, rpm to 79000, and neutral switch on?

Matt · Post by **Matt** » Sat Mar 30, 2013 1:03 pm

There is some glitch with the RAM perhaps in the ECU. The signals being passed via the USB cable are showing intermittent issue would suggest trying the board in another ECU

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signals spiking - but not conected

signals spiking - but not conected

Re: speed sensor spike - but not conected

Re: speed sensor spike - but not conected

Re: speed sensor spike - but not conected

Re: speed sensor spike - but not conected

Re: speed sensor spike - but not conected

Re: speed sensor spike - but not conected

Re: signals spiking - but not conected