Hi All,

Having had a 2000 Citroen Xsara Picasso for years with no issues (other than the usual servicing), I bought a second-hand 2009 one (1.6 petrol DOHC - nicely sporty, yes a Picasso, I know!).

All fine for a 1000 miles or so and then The Fault Light Came On (TFLCO). Diagnostic test said downstream lambda oxxygen sensor. That's a DIY job for me so I replaced it.

1000 or so miles, ok then TFLCO. Mmmm, diagnostics said the same problem. "Did you replace both?" asked my firendly local garage, "Er no" says I. So I replace both sensors and hurrah, fine for about 2500 miles ... then TFLCO.

But I fixed it, "How?" you ask. Easy!

THE FIX? I disconnected the battery and then removed the main connectors from the ECU / EMU (Engine Control Unit). Someone had spilled brake fluid into the central socket and it was obviously changing the electrical signal volvages. It took two goes to clean it out, no problem since.

This may not apply to many, but when you get TFLCO it's worth checking for brake / power steering fluid in all the connectors and sensors on the engine block near the fluid containers. DON'T just pay thousands to have all the sensors and ECU replaced. TFLCO is a known Citroen-wide issue that they, so I am told, have never fixed.

A GOOD TIP:After you have disconnected the battery for more than half an hour, when you connect it go for a drive of more than 15 minutes ASAP. This 'trains' the ECU to your driving pattern so include, for example, some 60mph and some town work.

Captain K

Edited by CaptainKephart on 20/08/2019 at 20:10