So the long awaited " special modification kit " eventually arrives, eager hands break open the sealed packages desperate to know what on earth can it be. ( that's your clue, earth )
Out falls three toothpaste type tubes complete with an instruction manual on how to fit
On the tubes it stated " special silicon grease " and to be applied in occordance with the makers instructions only.
What the hell?
What's this, another windup?
This Common Rail things another joke comment all hands.
The instructions would have been probably written by a lawyer rather than a marine engineer.
" extensive ongoing laboratory tests have revealed that in extreme conditions there could be an induced failure causing ECU 'S to go down onto Limpo mode or in some cases a complete shutdown mode may occur"
However should modification kit XYZ1234 be applied correctly and torqued correctly this should ensure that this will never happen and as such part of our on going commitment to our installations there is, as a gesture of goodwill no charge for the kit.
Probably hundreds of hours have been lost on not only down to Limpo but complete shutdowns have occurred .
We have lost a lot of hours/ days diagnostic time as we ( together with the manufactures ) have spent a lot of time unable to correctly diagnose the fault.
No admission of guilt whatsoever displayed here at all, just the helpful hand syndrome bullshit.
So as per the " it's only in case of " instruction book it's remove the ECU from its backing plate and turn it over.
Back then ( mid eighties ) two types of ECU 's , the self destruct one and the unbolt to split it one or the one whereby all components sealed in a resin filled box.
We called it the self destruct one on account of the fact the only way to get in it was to destruct it.
Looking at the back end where the ECU had been resin filled you noted that you could see the halfround sections of the resistors, diodes and the capacitators projecting up which although they were resin coated only had a thin smear over the top of the halfround sections.
Now this is where the fault lay, the ECU was tracking to earth intermittently on odd occasions/ temps earthing through onto the backplate to which it was mounted.
You should be aware, as we noted that this installation was NOT an insulated return system but an earthed set up as the whole engine/alternator / battery box was contained in a large lifting frame onto which the earth return battery cable was bolted.
Thus by bolting any earth return wire to the frame would provide an instant earthed return to the battery without running a separate feedback.
So it was apparent as to how this set up allowed the ECU to track through the back of the casing straight to earth and a complete shutdown happening.
So off with the tubes caps, squirt the contents into the back casing of the ECU until it projected over the casing height taking care no air-holes anywhere.
Bit like low tide really.
Although no explanation was forecoming we deducted that by two stage torqueing the ECU to the backplate that an even " spew out " of the special silicon grease " ensured a blanking / insulated condition now existed between The ECU and earth.
Two stage torqueing the ECU bolts using a wrist watch torque wrench the job was left overnight to " cure."
Amazingly this really worked and no more problems ensued.
Several months later we had to fit new ECU 'S and send the original ones back, the new ones were resin filled flush with the casings sides, in other words high tide prevailed here all right.
Talk about live and learn!
All this was approx. 1985/6 and I have to say with me it never happened again re ECU tracking.
So just when you think you are getting a handle on it all along comes something like this and you realise you still have a long way to go and that five year apprenticeship is still running all those years later.
Think on this occasion Mr Siemens was the culprit.
Like I said , unless this has happened to you personally very difficult one to crack, as Mr Siemens probably thought at the time but of course never admitted.
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.