Got a phone call from SWMBO today in a bit of a panic as the EPC and Emission warning lights had come on in her Leon (1.6 16v). Both lights were on constantly rather than flashing. She said the car seemed to be running fine.

Of course by the time I got home the lights were off and there were no faults recorded when I plugged VCDS in. I took the car out for a drive and all seemed fine except that there seemed to be a lot of ticking from the charcoal canister in the engine bay. Being hard of hearing I'm not sure if it was ticking more than normal or whether I noticed it because I was listening for funny noises.

I'll keep an eye on it but anyone got any idea on the possible cause or was the car just having a funny 5 minutes?

Bump.

When my coolant temperature sensor went, I had no fault codes but an intermittent warning light on the dash. Only found it by checking for fault codes when the light WASN'T showing, and discovering that there was a 'pending' code logged. I believe these arise when you get a certain number of spurious signals in a certain amount of time, rather than a continous one...

When my coolant temperature sensor went, I had no fault codes but an intermittent warning light on the dash. Only found it by checking for fault codes when the light WASN'T showing, and discovering that there was a 'pending' code logged. I believe these arise when you get a certain number of spurious signals in a certain amount of time, rather than a continous one...

Hmmm. When I scanned the car the lights had gone off. After a spot of browsing and looking through the haynes manual I had started to suspect the CTS or the purge valve in the charcoal canister, or possibly a coil pack, though the fact it was running fine the whole time made me think this was less likely.

If it IS the CTS, the effect on the performance may well be hard to detect, especially if it's reading low since it's cold anyway...