[knous81]

My friend has a 2018 430i gran coupe that I pulled these codes on. After searching on here, it looks like it’s one or more of three things. Fuel cap, fuel tank vent valve, or leak detection pump. What I wasn’t able to find in any post is if there’s a process to narrow down which one of these we should replace first, rather than just starting at the cheapest part. Is there a diagnosis process we can run to help narrow down which item or items are failing without just starting to buy parts first? Thanks

[cfm56d7b]

knous81, caveat being remote diagnostics are what they are ..

The reasons for error 190302 could be ...

- Worn or defective gas tank cap
- or Diagnostic Module for Tank Leakage (DMTL) pump

There was technical service bulletin published in August 2016: SI B01 09 16 titled N55 LEAK DIAGNOSIS MODULE (NVLD): LIMITED WARRANTY EXTENSION TO 10 YEARS/120,000 MILES.

Only N55 equipped models were included. So it doesn't include your vehicle. But there might be an equivalent bulletin for your vehicle's engine. Worth researching.

Overview of how DMTL pump works on BMW X5. https://www.princeton.edu/~sdepasqu/...k.Diag.Sys.pdf

[TZ]

Thanks for the info

[knous81]

Originally Posted by cfm56d7b

knous81, caveat being remote diagnostics are what they are ..

The reasons for error 190302 could be ...

- Worn or defective gas tank cap
- or Diagnostic Module for Tank Leakage (DMTL) pump

There was technical service bulletin published in August 2016: SI B01 09 16 titled N55 LEAK DIAGNOSIS MODULE (NVLD): LIMITED WARRANTY EXTENSION TO 10 YEARS/120,000 MILES.

Only N55 equipped models were included. So it doesn't include your vehicle. But there might be an equivalent bulletin for your vehicle's engine. Worth researching.

Overview of how DMTL pump works on BMW X5. https://www.princeton.edu/~sdepasqu/...k.Diag.Sys.pdf

New gas cap installed and 4 days later, same two DME codes. What next, DMTL? Thanks