DMTL Pump Replacement 2010 135 Code 2B3A

[Security_IE]

Plenty of info on changing these on a 3 series but I didn't find anything specific to the 1 series. Here are some photos I took changing the pump on my 135. Took about 45 minutes total.

My Service Engine Soon light came on. I pulled the code with INPA as 2B3A, DMTL. The 5833 line translates to "Pump current too high during reference measurement", so I ordered a new pump. My understanding of this pump is that is draws the vacuum for the fuel system to detect leaks, such as the gas cap being loose.

The pump is attached to the charcoal canister in the right rear of the car, under a plastic access panel. I jacked up the back right corner at the normal jack point to give me a few more inches of clearance. The panel can be pulled down after removal of a few 8mm screws and 10mm bolts, which are all clearly visible.

The canister is held in place by two 10mm bolts and will drop down enough to disconnect the electrical connection and the hose from the pump.

To disconnect the hose from the pump, you need to slide the plastic ring on the hose fitting back, as the pump is barbed on the end (see photos).

Disconnecting the hose allows the whole assembly to drop down further, making it easy to reach the three T20 torx screws that hold the pump to the canister. You can get to the T20s before disconnecting the hose from the pump if you prefer. The other hoses do not need to be disconnected from the canister.

Remove the pump from the canister by pulling it out of the canister towards the front of the car. There is a rubber seal on the end of the pump that goes into the canister. Once removed, move the rubber seal from the old pump to the new pump. My new pump did not come with this seal.

Reinstallation is simply in reverse order. This was a very simple process with minimal tools needed.

Good luck!

[BMWCCA1]

Thanks. I need to do that on my 128i.

[BMWCCA1]

Originally Posted by Security_IE

Plenty of info on changing these on a 3 series but I didn't find anything specific to the 1 series. Here are some photos I took changing the pump on my 135. Took about 45 minutes total.

Where about in Central VA are you?

Thanks again. I'm doing the replacement right now and, even though I am also from Central VA, my car came from Wisconsin and has a different distribution of corrosion than yours is showing! Those little T20s are getting a coating of rust primer aluminum prior to reinstalling. Some of those 10mm bolts came out with their Ikea-looking inserts into the fuel tank. I don't think there's much point in separating the bolt from the insert, I'm just putting them back in the way they came out! I removed both hoses from the canister to get better access to the hose on the pump and then the whole thing was free to take to the bench for the correct TorX size. Once you get one hose loose, it's easy to see how they're supposed to come apart. But they were stuck, for sure. Just a squeeze didn't work and I had to help the release collar with a small screwdriver under the lock tab.

It's also a great opportunity to put a hole in the passenger-side rear trunk-well where the modules are stored and can get filled with water. Just drill one in the plug that's already there and you're done with water filling up the compartment. If you can find the leak, more power to you, but at least this way the entire compartment won't fill up with water and drown the Comfort-Go module.

Thanks again. Back to it after the paint dries!!

All done. Fault cleared. Test-drive complete. "Service Engine Soon" light is out.