Apr 27 • Your Own Faults. Videos/pics
2011 Fiat 500 crank no start
Mentioned this one on a Monday live session a week ago customer stated one morning wouldn’t start. No warning lights
Scanned no codes, Carried out basic checks, had spark and good compression, had fuel pump priming and was petrol. Crank and cam synced up, rpm sensor reading. Battery good
Further diag ; had 5 bar pressure at the fuel rail, scoped the fuel injectors and found a very strange wave form, pics below.
Thought maybe a poor ground maybe be the issue as it looked to be roughly right but a lot of interference in the wave form. Noticed the ground cable from the top of the gearbox and been replaced with what looks to be a very cheap strap that I wasn’t happy with. Replaced this for a decent one and cleaned the contact points as were a little corroded. Wave form didn’t improve but was much more repeatable as before wave forms were was some intermittent.
Checked a wiring diagram, goes from PCM through one connector to injectors. Removed all connectors all okay, tested voltage all okay.
Had a LKQ remotely plug in as i found it unclear with the autel if maybe the immobiliser was stopped it from starting, apparently it’s all okay.
No updates
No codes
All modules have comms
There was one bulletin for a software update but the vehicle was too old for remote updates
I remember we talked about checking 5v outputs from a modules to see if they had gone down haven’t checked this yet but it’s my next check.
Otherwise everything is pointing towards PCM.
Anyone have any thoughts?
Pic 1 injector wave
Pic 2 pico supplied known good
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2011 Fiat 500 crank no start
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