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Motoring Discussion > Home mechanics	Accessories and Parts
Thread Author: tyrednemotional	Replies: 32

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Wed 2 Oct 24 21:02

Home mechanics - tyrednemotional

As vehicles get more and more complex, the difficulty of working on them as a home mechanic has increased almost exponentially.

Certainly, it inhibits me from attempting anything but the most obvious of things on either of the cars.

Funnily enough, however, I'm happy to go somewhat further with the motorhome, the most costly of our three vehicles. I'm reasonably mechanically aware, but also very aware of my own limitations, both technically and physically (and my lack of some tools). I've serviced the motorhome to dealer standards since purchase, with the exception of the required cambelt change at 5 years (it being a far from easy job without a pit or lift).

I'm aided by the fact I have aftermarket, but dealer-level, software which allows virtually complete diagnosis, adjustment and code resetting. In the later Ducato versions this has been negated by Fiat locking down 3rd party access via the OBD port.

Before and after long runs, I tend to do a code-read just to check everything is OK. It was clear before the recent 2.5k mile European trip, but after return there was an engine code indicating (an?) intermittent electrical fault with the "blow-by heater". The advice was that the EML had not been illuminated, so clear the fault and check for re-occurence. That I have done and am doing respectively.

Now the blow-by heater is part of the gas recirculation system, and is designed to avoid delivering ice-crystals into the turbo feed! Historically, somewhat older models used to blow a (shared) fuse when there were problems with this heater or circuit. The advice for this was simply to detach the electrical connector to the blow-by heater, replace the fuse, and run as normal (with the other items on the shared fuse now working again). The provision is largely for near-Arctic conditions, and of little consequence in most of Europe.

In later (Canbus) models like mine, there is no fuse. The electrical supply is managed by the engine/body computer, which inhibits the feed in case of problems without affecting other circuitry. Unfortunately, in the case of "hard" or repeated issues, the EML is now illuminated (though there is no effect on engine or emissions performance).

I'm no great believer in intermittent problems going away, so, though I shall retest at intervals and keep my fingers crossed, I'll likely try to address the issue. (It isn't entirely uncommon). It has to be said that, even with the EML lit, there is no downside in running, except in determining that is the only issue that has lit it.

Looking at parts diagrams, I was dreading it, but luckily I couldn't match the diagrams and parts pictures because I was one year out with the research, and for my engine the part (a PTC heater in a hose) is redesigned and much more accessible than first thought, at the top of the engine. Worst bit will be removal of one Fiat proprietary single-use hose clip (the other more remote but still accessible end is push and clamp fit).

The part is about £160, which is excessive for what it is, but I can obtain used for £50 (which is tempting). Alternatively, apparently I can put a bit of 1 amp fuse wire across the feed terminals to inhibit the EML (really, it's the appropriate resistance). The latter is not my preferred option ;-) .

I'm considering changing the 'van for one last time, but the inability to do the equivalent of some of the above due to the OBD block is certainly giving me pause for thought.