Technical Intermittent amber Engine ManagementLight

[Vespasian]

I have owned this 2007 2.3 multi jet Ducato motorhome for last 9 years and it has been ultra reliable. About 2 months ago the EML started illuminating intermittently.
Sometimes from start up, sometimes after about 5-6 miles and sometimes not at all for a hundred mile trip. I can sometimes appear to cancel it by a combination of removing or changing the key in the ignition.
There appears to be no discernible effect on the engine in terms of power delivery, fuel consumption or emissions (service and Mot 6 weeks ago) In the last month I did a 1000 mile trip in France with the EML intermittently illuminating. I've also noticed that the brake warning light illuminates very faintly (new pads fitted 1800 miles ago and reservoir fluid level good.
I have taken it to my garage this morning and they have reported several historical error codes identifying the throttle body, and recommend a replacement to the tune of £950. They are reluctant to investigate the brake light until this has been done as it may be related and are not 100% sure this action will cure the main problem.
What does the Forum think as I'm reluctant to authorise a replacement that may not cure the issue?

 

[the green vanper]

Hello,

Earths and oxidation due to water ingress. That's what you should start with.

The main earth strap body to engine / gearbox earth strap, preferably attached to a different point on the body. Then, the earthing point by the left headlight.

The earth points tend to rot, same for the cables (they rot on the inside, it's difficult to see at first glance).


Then, the scuttle tray lets water into the engine bay. The ECU is the first module that gets damaged (the connectors), there've been reports that water was getting through the wiring looms event to the BCM.

There are several threads on the scuttle tray repair on this and mh forums.