[Nickf33]

Hi all, new to the forum. Here’s where I’m stuck

My boss owns this 335d. SES light comes on. She goes to bmw, they cited def pump needs changed and quoted her over 4k to fix.
She asked me to see what i can do (i build pushrod v8’s as a hobby, i can turn a wrench)

I access pump on top of def tank, note that the nipple is broken off where it connects to hose. Pump was just spraying def everywhere. Area covered in crystal buildup. THIS MUST BE THE PROBLEM??

I order brand new oem replacement, prime, install, connect all fittings, fill def tanks, start car.

Car has 2 codes.
- P20A0: reductant purge control valve circuit open. (BMW code 46AF)
- P0638: throttle actuator control/range performance bank 1. (BMW code 4687)

Shame on me, I did not check what codes were present before working on car. So I have no clue if these are new or existing.

Is there something I’m missing? Primarily the P20A0 code. Is there a fuse somewhere I can look at? Can I test the new pump somehow?

This emissions system is a joke that I would suggest delete but we are in California. Any help would be great. I’ve dived all through the internet and it’s gotten me nowhere.

[Nickf33]

3 images:
Before removal, after removal, codes

[Nickf33]

Bump.

Does anybody do diagnostic around here that can help or are we all just a bunch of frat boys that bolt on new parts and don’t know jack…???

[POBEP]

46AF
Replace delivery module - DEF pump.


It is leaking.
Connector fails when line attached by inexperienced mechanics.
It happens when BMW dealership replace DEF tank (incorrectly) under warranty.
valve reported by the code is inside the pump.

Forget about $4k - it is rip off by someone who has no idea what they doing.

You can get used pump free or under $100 in this forum.
If you go with new one - get Bosch F01C600210
(BMW does not make this part - it only resell it for profit 16197244137)

There is an ISTA test for DEF injector metering quantity - you can use it to test DEF pump (I did)
I recommend doing it anyways as you'll have to take out DEF injector and wash it (water only)

If you already assembled everything - clear old codes and run above test.
Then check for codes again.
If you put everything back properly, the 46AF will not come back.

When you assemble the pump, pay very close attention when attaching metering line to the pump.
It is easy to break pump-2-line connector.
follow newtis instructions closely


Side notes:
It looks like you went from the trunk.
I went newtis route - dropped exhaust.
It was not hard.
But, it allowed me to take out SCR tank and wash it outside, and more importantly inside.

Consider checking mixer installation direction.
Mine was installed wrong way by dealership

[POBEP]

Originally Posted by Nickf33

This emissions system is a joke that I would suggest delete but we are in California. Any help would be great. I’ve dived all through the internet and it’s gotten me nowhere.

M57 emissions system is well designed.
The issue is that here in US almost no one read the service manual from BMW.
Including stealership mechanics.
It is actually simple and easy to fix.

The main curl-pit is failing M57 thermostat that eventually kills emission components.
Its failure often ignored and then dealers wants $$$$ to replace everything.

[Nickf33]

Originally Posted by POBEP

46AF
Replace delivery module - DEF pump.


It is leaking.
Connector fails when line attached by inexperienced mechanics.
It happens when BMW dealership replace DEF tank (incorrectly) under warranty.
valve reported by the code is inside the pump.

Forget about $4k - it is rip off by someone who has no idea what they doing.

You can get used pump free or under $100 in this forum.
If you go with new one - get Bosch F01C600210
(BMW does not make this part - it only resell it for profit 16197244137)

There is an ISTA test for DEF injector metering quantity - you can use it to test DEF pump (I did)
I recommend doing it anyways as you'll have to take out DEF injector and wash it (water only)

If you already assembled everything - clear old codes and run above test.
Then check for codes again.
If you put everything back properly, the 46AF will not come back.

When you assemble the pump, pay very close attention when attaching metering line to the pump.
It is easy to break pump-2-line connector.
follow newtis instructions closely


Side notes:
It looks like you went from the trunk.
I went newtis route - dropped exhaust.
It was not hard.
But, it allowed me to take out SCR tank and wash it outside, and more importantly inside.

Consider checking mixer installation direction.
Mine was installed wrong way by dealership

Thanks for giving me something to work with.
When I had some time in the shop today I plugged in the old broken pump just to see what happens and code went away. Making me assume the new replacement pump (Bosch) just happened to be faulty because I have bad luck like that 🤷‍♂️
I have another pump coming, hopefully this solves the issue.

I will check the mixer orientation and also clean the def injector since you mentioned.

👍👍

[POBEP]

Originally Posted by Nickf33

Making me assume the new replacement pump (Bosch) just happened to be faulty because I have bad luck like that.

I had similar "luck" twice so far with 335d.

I bought it with glow plug module code.
wont pass smog with CEL on.
The seller stated that both module and plugs were replaced recently.

I pulled one he had - it was Beru, made in Germany.
Replaced with BMW-branded, made in Romania.
No issues for past 3 years.

Then last year rear wheel bearing failed mechanically.
I replaced it with BMW one.
Put everything together (royal PITA to press it out and in)
The magnetic ring on the new bearing was faulty.