CADDY2K.com

Just wondering if anyone can have a quick look over the Vcds readings on my
AdBlue system.

Roughly 1 month ago my AdBlue was down to 2500 miles so I topped it up with a few litres from a big drum I had until it sounded pretty much at the top. Previously the Range has correctly almost straight away or after a short trip.
Anyway after a full week of driving it was still saying 2500 mile so I thought I’d not filled it enough so got the bottle out and filled it until it overflowed and thought about getting it mapped out of the system. Few days later the Range went to 4000 so was happy to see that but every other time it had read 5500 from full.

Fast forward a month to now the range is still… 4000 miles despite doing over 1000 miles and three tanks of fuel.

Tonight I put Vcds on and did a full scan before doing some other upgrades and had a NOX exhaust sensor fault, I did a full system clear to reset everything and the fault never returned but the range corrected itself to 4500 miles now (which would be correct if it had of read 5500 from full like usual, minus the 1000 miles I’d done)

Figured I’d check some live data to see what level it’s at or anything else I can keep an eye on and from what I can see the level says it’s 179% full…

I had a similar issue when my nox sensor failed, I had an emissions fault on the dash and mileage countdown for the adblue system. I checked the values in VCDS and they were out of whack like yours. When I spoke to a garage he said that VCDS is too out of date to properly speak to the adblue system, you need ODIS.

I had VW run a test plan on the van and they were able to identify exactly which part was at fault rather than throwing parts at it. Cost around 80 quid for them to do the diagnostics which I think is reasonable. Then you could change the part yourself (if it's dead)

Worth checking out because if the adblue system is in fault the DPF won't be regenerating properly which can block it. That'll cost you a bomb to replace. Mapping the stuff out will fail the MOT too