Questions about error code 004B82

[Svaen]

Hi, I had the check engine light and error code 004B82 - exhaust gas recirculation rate control, control deviation.
It led me to believe that my EGR valve was stuck in open position, so I replaced it with a new one, and the error code went away.
But now it’s back, just three days after the EGR replacement.

I’ve found this online:
https://static.nhtsa.gov/odi/tsbs/20...47005-9999.pdf
But at the same time I don’t feel like using money on new EGR cooler, etc without this solving the problem.

Anyone who has had this error code, and solved it?

[Thecastle]

Yes, I’ve had it numerous times. Could be a cracked egr cooler, bad maf sensor, bad exhaust pressure sensors. Egr leak, it could Be a lot of things there should be other codes also to help narrow it down. It’s going to be an air leak, plugged or a bad sensor.

[Svaen]

It’s weird that there are no other error codes, just the 004B82, and that the error code went away for a couple of days after replacing the EGR valve, but that could be the placebo effect.
Guess I have to start off on the cheap scale of the checklist and replace the intake sensor and check for leaks around the EGR cooler and charge air pipes.

[robinasu]

I had a bunch of EGR codes (forget them) when I first got my X5d. The code you have talks about "control deviation." The low pressure EGR actuator has position feedback. In my case the pressure converter (vacuum modulating valve for the low pressure EGR actuator) that controls vacuum to the EGR actuator was broken and the EGR actuator position feedback did not indicate any commanded movement.

Also, the link you provided talks about the crankcase ventilation hose/heater. It's very common for that hose to crack open. TunemyEuro has a CCV hose for that.

eBay sells pretty cheap smoke machines for diagnosis. Hope these help.

[Svaen]

Thank you robinasu, I’ll try to replace the electric vacuum valve and the crankcase ventilation hose, and go from there. Maybe get some new vacuum lines for the vacuum valve too, just to be sure.
Maybe it could make sense somehow, that the error code went away and came back with the new EGR valve installed, if the vacuum valve is the problem.
Will post back with the new parts fitted.

[robinasu]

It's a real pain to get to the low pressure EGR pressure converter. You have to take off the intake. I recommend you or somebody follow the fault finding in ISTA+ to check the pressure converter with a vacuum gauge. The test procedure exercises the pressure converter to output a couple vacuum levels. You snip the correct vacuum hose and attach a vacuum gauge and run the procedure. You will need a coupler to reconnect the hose when done.

I would check the CCV hose, first. Could be a quick win- it's not hard to get to.

[Svaen]

Oh, I thought it was nr. 14 on the picture, says EGR electronic controller valve.

Anyways, new CCV hose with seals and this controller valve will arrive tomorrow, set me back with 60$ so not a huge loss.
Will go on with the vacuum if it’s not my lucky day.

[robinasu]

That is the high pressure EGR gas enable vacuum control valve and it is only open/close and there is no electrical position feedback. There is a vacuum operated flap in the the hp-EGR cooler pictured in your image used to stop/enable EGR gas flow. The vacuum actuator is #2. There is an ISTA+ test function for #14 as well. Actually, check the coil return spring on the flap lever arm on the high pressure EGR cooler in your image. It commonly breaks, too. Mine did - used a hardware spring to the side of the engine compartment as a temporary fix. If the flap doesn't return to a default position with the engine off, it's probably broken.

The low pressure EGR cooler is down near the DPF. You can see a vacuum line heading down to the LP-EGR actuator from under the intake manifold as it runs by the CCV heater / upper charge intake pipe. Be really careful messing with the vacuum line at the actuator. The plastic may be brittle and you can snap off the nipple where the vacuum line connects. (Bad news) That vacuum line runs to the LP-EGR "pressure converter" than can modulate the vacuum (not just on/off) and its under the intake manifold. Thanks BMW.

[Svaen]

CCV hose and EGR vacuum control valve are replaced, but no luck
I see the lever arm on the cooler is moving when the engine is running and hot, and that it goes back when the engine’s off, so guess the spring is ok.
Guess it’s on to the next task now.

[robinasu]

Originally Posted by Svaen

CCV hose and EGR vacuum control valve are replaced, but no luck
I see the lever arm on the cooler is moving when the engine is running and hot, and that it goes back when the engine’s off, so guess the spring is ok.
Guess it’s on to the next task now.

This was the hp-egr valve right? Hard to know what to do next. ISTA+ really is helpful if you like to DIY. I would get ISTA+ going as the next task, but that is just me. Once it's working you can perform the test functions needed to narrow down the possibilities. It's a task to get it running and to ramp the learning curve, but worth it if you will keep the vehicle for a while.

You can buy pretty much working packages from our Russian friends on ebay. Or this: h t t p s: / / w w w . b I m m e r d I a g n o s t I c s . c o m. I have not used them but they look ok. Or, you can find the downloads. You need a ODB to USB cable.