2012 X5 diesel reduced power with lots of codes

[Tractorguy77]

Hello, happy 4th!

A couple days ago the 2012 x5 diesel got the first reduced power msg with roughly 130k miles on the clock. Lots of codes, 13 to be accurate:

46F9
4507
4BDC
4862
48DC
4B82
4C83
4370
44DD
3F25
3FF0
4865
4530

I checked on carbon build up, see image. There is some... i have no reference if it a lot of not.

How do I start diagnosing the issue? any leads?
Cheers!
H.

[sunny_j]

You can start by writing out the descriptions for each code...

[Tractorguy77]

ok. here is what i found...

Seems to be related to the EGR. With all these codes, how do I go about testing? What is a good place to start?

At first I thought it may be vacuum related. When I turn on the car I can see the valve at the EGR cooler and turbo control move. Would that point to the vacuum system being intact?

46F9:
reducing agent active tank temp sensor open

4507:
Exhaust-gas recirculation, control deviation

4BDC:
DDE: Fuel presupply-pressure control

4862:
Air system, air to EGR mass flow, plausibility

48DC:
Boost pressure sensor, plausibility

4B82:
Exhaust-gas recirculation-rate control, control deviation

4C83:
Exhaust backpressure before exhaust turbocharger, plausibility

4370:
Exhaust gas return-rate control, control deviation

44DD:
Exhaust gas return-rate control, control deviation

3F25:
Charge air hose monitoring

3FF0:
Air mass measurement

4865:
Air system, air to EGR mass flow, plausibility

4530:
Charging pressure control, control deviation: Charging pressure too low/positive control deviation

[Thecastle]

You have a leak in the egr system. It’s either one of the dpf Pressure sensor lines burned through, a cracked egr cooler or a plugged egr valve. Less often it’s a bad maf and pressure sensors.

You also have a bad scr tank. The heater can be replaced by a toureg scr tank heater for a big cost savings.

[Tractorguy77]

Thecastle, thank you very much! Would you be able to point which one is actually leading to the reduced engine power problem? I am looking to get this done first.

I looked at the erg cooler and cannot see any leaks, no fluid and no sote around it either. Are there other signs I should watch for?

[JDAURIA]

Isn't the SCRA tank covered under extended warranty? You are just outside the 120k mile but within 10 years. Maybe a dealership will go out on a limb for you (goodwill).

[grapes11]

SCRA is tank covered under extended warranty? 10 years 120k from in date of service .

[Tractorguy77]

Thank you for all the responses! Last week I ordered a set of vacuum hoses to be prepared, those arrived yesterday. This morning I went and checked the exhaust gas pressure line which seems to look ok... at least to me. When I started the car I was surprised to not see a warning on the dash. After driving it a bit it showed up when I went up a hill and went into reduced power mode. Is this fault always intermittent?

[sunny_j]

The EMP hose may look fine but I'd remove it and see if it's clogged

[Tractorguy77]

Got it figured out... was the map sensor. Replaced in less than 30 minutes and limp mode gone, however, still the following codes left:

1) 4BDC
2) 46F9

The last one is obvious. How about the first... could a clogged fuel filter trigger it?