Can signals.

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Can signals.

Postby legacy01 » Sat Feb 18, 2012 8:18 am

Hi guys. First time forum user and first time I have used my recently acquired pico so pls excuse my inexperience.
Ok here goes. 2004 mini cooper s came in with an array of warning lamps on. Abs/dsc, tyre press monitor, brake warning lamp, speedometer inoperative and temp gauge reading full pelt as soon as ignition on. Used dec super scan and read fault codes from abs/dsc unit. No can communication between abs and all other modules on network which consists of engine ECM, instrument cluster and steering angle sensor. Can wires do not terminate at diagnostic plug so I decided to start under bonnet at abs/dsc module. Back probed can signals at module and both signals were a mess. Totally unrecognisable. Like someone threw a grenade in there! After a bit of thinking I moved inside car to steering angle sensor located on column. Probed can again. Messy but better, almost able to make out something faintly recognisable now and again. Left trace running and unplugged abs/dsc module and almost right away trace changed to what I would say was a nice clean can bus signal with high and low mirroring each other perfectly. Incidentally temp gauge also returned to normal reading. Reconnected abs and everything went t-ts up up again. Did this several times to be sure. My way of thinking is faulty abs/dsc module? Have checked all supply and earths to it and all are good with no voltage drops. Sorry I don't have any traces to include with this post but barely learned to switch scope on so far. Lol. Anyway I would really appreciate any thoughts, hints or tips you guys may have on this fault. Thank you for taking the time to read my ramblings!
legacy01
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Location: North Ayrshire

Re: Can signals.

Postby malcolm tripp » Sat Feb 18, 2012 6:15 pm

Your diagnosis looks good to me, well done
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Re: Can signals.

Postby GRUSS » Sat Feb 18, 2012 6:39 pm

Hello there from a fellow new scope user. How you finding the pico?

It certainly sounds like you've covered all corners, I had a astra h last week with no comms with cim on can high network.my problem was that the can h and can l wires were shorted to ignition voltage. The problem was the electric steering pump. I could see this on the scope straight away and unplugged everything on the network until I got a clear picture of the mirrored waveform. So going on what you have done i would say that the abs is the faulty component. :D

Russ
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Re: Can signals.

Postby legacy01 » Sat Feb 18, 2012 9:17 pm

Thank you for taking the time to reply. Really enjoy using the scope, incredible bit of kit. I have alot to learn ahead of me mind you. Glad to hear someone agrees that I I'm hopefully on the right track with the mini.

Many thanks for sharing your thoughts
legacy01
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Posts: 2
Joined: Sat Dec 24, 2011 5:58 pm
Location: North Ayrshire


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