CEL -- Code P203A

[Der Kaiser]

CEL came on last night and I checked the code today and it showed P203A --- "Reductant Level Sensor Circuit"
After researching it came down to an issue with the DEF tank issue. Anybody had this issue before? I would like to get some more info before I go to the dealer.

[JoeyBimX5din]

its like a fuel sending unit, but for your pig urine container. There is probably a ohm chart that should show you what ohm level you should have at what DEF tank level, if you wanted or had the ability to troubleshoot it yourself.

I took a look through Mitchel. The BMW procedure has the tech look at the DEF level sensor through the scan tool, if there is a reading then it may be OK, if there isn't, verify the connector pins and if they are OK, replace the level sensor. If you don't have a scan tool that can see that pid, you may have to rely on the dealer

[Der Kaiser]

thanks for the info. I'll check it this weekend.

[Der Kaiser]

Update -- The light was on this morning but after topping off the DEF it is gone. It took almost 2 gal. to fill both tanks. Hope this solved the problem. I'll keep you posted.

[JoeyBimX5din]

how big is the DEF tank?

[Der Kaiser]

according to this link: https://www.press.bmwgroup.com/usa/p...tem=node__4310

Active tank = 1.6 Gallons

Passive Tank = 4.5 Gallons

[JoeyBimX5din]

so you were bone dry.

[Der Kaiser]

not really. 3/4 gal in the primary and the rest in the passive tank. But I think there is room for more in the passive but I ran out of DEF. I'll get more this weekend.

[JoeyBimX5din]

sorry, sleep deprived look at the forum. Thought the size of the DEF tanks was in quarts, not gallons.

Has that code come back? It is more then likely a fail DEF level sensor