BSI permrnant fault, no communication with ECU.

[finchy]

OK so the status of my fault has now changed!! It's now as per title when read with Lexia, please can you guys share your experiences on things to check?

[Rustscrat]

Has the Bsi got wet or is there any signs of dampness around it etc. cratch:

[finchy]

No it hasn't, this fault has been intermittent and only on cold damp days with no ECU logged faults which led me to believe poor earth point somewhere. Today it became Permanent and i could read the logged fault with Lexia. Ive had all the electrics out in the engine bay, ECU, wiring looms etc, emery clothed all earth connections and sprayed everything with contact cleaner, re-fitted it all and it fired up! We'll see what happens in the morning!

Never a dull moment with french cars hey?

Just found a nice 42k mile Mazda 323 for my sister - tempted myself! Had 4 Honda Civics in the past, never a moments bother!

[Rustscrat]

Ok, with the ignition on, do a global diagnostic check with Lexia. You should have a list of the ecu's and an answer of yes or no in the "dialogue" column.
What are the results?
Also is the mileage showing up in the clocks and is the air bag light lit all the time? :thumbsup:

[finchy]

When the fault is present the only fault is showing is in the BSI dialogue, 'BSI permenant fault communication with engine ECU' and it basically says Short circuit to earth for every function, list with 100s of em.

ECU out, put it in a warm place for an hour (airing cupboard) and hey presto no faults engine starts ok no more faults in BSI. But tried again this morning and same problem.

I'm suspect there's a bad contact on the map chip from when it was unsoldered and re-soldered back on from when it was remapped!

I'm going to try and get hold of the guy who did it and get him to re do the work.

[chronyx]

Cold and damp may cause just enough condensation for a short to earth as I guess these components are sensitive down to millivolts.