As I've kind of hinted in other threads recently, I've been trying to pin down a rogue engine management light (or exhaust system thingamidoodah to be more precise). Being short of a laptop chez Ap0gee ATM hasn't helped, but at last I got the light to show when my standby code reader was plugged in. And...

1 fault found

"N/A"

Annoyingly, sometimes the light stays on when I start the car, sometimes it goes out as normal, and sometimes it comes on mid-journey! The only thing I can say for certain is that if the glowplug light takes longer than normal to go out, I'll have a little orange engine decorating my speedo for the rest of the journey. :(

Could it be as simple as a glowplug on its way out? It did come on shortly after a dose of injector cleaner, although I dig rag the car somewhat when down at Brunters at that time too, so maybe that's got something to do with it? There's no loss of performance, so maybe I should just put up with it for now and be glad my naffo code reader still gives me the wherewithall to clear the fault... :confused:

Could be as simple as the coolant temp sensor. You really need VAG COM or dealer diagnostic equipment to get a propper fault code report.

Thanks, matey!

Having at last managed to get it to show so I can clear it, it's stayed away for the last 4 or 5 trips - fingers crossed it stays that way until service when I'll mention it to the folk at the garage!

Hmm, interesting...

After a hiatus of a few weeks, the warning lights are back. it started with the coolant level sensor (definitely spurious, goes away if I switch off and on again - must get the tank changed ASAP ), and then the engine warning light again, with 'N/A' for the fault code.

Then yesterday, I hoofed it to move from Lane 1 into a gap in Lane 2, and got the PAS light, ABS light and the airbag light, accompanied with 3 beeps. Got off the gas, and the lights / beeps went away again. No light , but a 'pending' fault code stored: P00118 Engine coolant temperature circuit high input. This has now gone, but the coolant level warning happened again this morning and the CEL light with the 'N/A' code was back too! I'm assuming 'high input' means the signal is high rather than anything else, as I've been keeping the coolant level a few mm above the MAX line as this (for a while at least) cured the coolant light issue. Then again, that's level rather than temperature. But then again, again, the two things show the same warning on the dash, so maybe it is that??? :confused:

I am hoping that it's just the dodgy coolant level sensor that's making the ECU act a bit mental, 'cos yesterday's antics weren't pleasant at all... :(

Seem to have got to the bottom of it:

While my code reader would show 'N/A' when the CEL was showing, a bit of lateral thinking uncovered that the P0118 code was showing as 'pending' whenever the CEL wasn't lit! A quick look on the Ross-tech Wiki highlighted a few familiar symptoms (glowplug light taking a long time to go out, fuel consumption worse than normal) so I decided to replace the coolant temp sensor that is related to the P0118 code. So far, no CELs and no pending codes!

As a footnote, I also tried to fit a new expansion tank to avoid the spurious warnings but somehow ended up with a slightly different one so have temporarily resorted to shorting the terminals of the sensor. Unfortunately, I can't try to clean the prongs (even though a certain garage said they had done so already ) since the inside of the tank has a sort of weir that hide the prongs! Anyway, as long as I check the level regularly (you wouldn't rely on the oil level sensor before checking the dipstick, after all!) it should see me BEEP BEEP BEEP free until I can sort out the correct tank...

All in all, v. happy again! Here's hoping it lasts!

Cleaning those prongs is damn near impossible - and not worth the effort IMHO

I've found in the past that alloy wheel cleaner or wheel acid to be effective, but at what the expansion tanks cost new, is it worth it?