[xiola650]

Hello!

I have a strange issue. Shortly after purchasing my used E90 the check engine light came on for codes 2A00, 2AAC, 2DED and 2ADA. I figured I would start with the first code and work my way down the list.

I started with replacing the secondary air pump and check valve since it seemed to not be blowing full force. No change after doing so, so I checked for blockages and I did not find any. Full flow coming right out at the exhaust. I cleared the faults and they keep returning after the third start up. All 4 at the same time approx 10 seconds after cold start up. I started to think maybe its an electrical issue? So I updated the DME. Still no change.

Before I start throwing in DISA valves, a BST and a radiator ($$$) I figured why not try here and see if anyone has run into this before. I'd hate to install all that and still have the same problem considering the first fault won't clear after replacing the pump and valve. Maybe I missed a step with the secondary air system or could the DISA cause the secondary air fault? Any input would be greatly appreciated!

[d1saster]

What is the description of those codes?

[gbalthrop]

Originally Posted by xiola650

...Shortly after purchasing my used E90 [2007 E90] the check engine light came on for codes 2A00, 2AAC, 2DED and 2ADA. I figured I would start with the first code and work my way down the list. I started with replacing the secondary air pump and check valve since it seemed to not be blowing full force. No change after doing so, so I checked for blockages and I did not find any. Full flow coming right out at the exhaust. I cleared the faults and they keep returning after the third start up. All 4 at the same time approx 10 seconds after cold start up. I started to think maybe its an electrical issue? So I updated the DME. Still no change...

Originally Posted by d1saster

What is the description of those codes?

Code Definitions per Bentley:

P0491 | 2A00 | Secondary Air Injection System Insufficient Flow (Bank 1)
P16C5 | 2AAC | DME Main Relay Switching Delay
P14C3 | 2AAC | DISA (Differentiated Intake Manifold) Actuator 2 Fault
P160F | 2DED | Powermanagement No Load Current Error
P2568 | 2ADA | Direct Ozone Reduction Catalyst Temperature Sensor Performance
P2569 | 2ADA | Direct Ozone Reduction Catalyst Temperature Sensor Circuit Low
P2570 | 2ADA | Direct Ozone Reduction Catalyst Temperature Sensor Circuit High

You say: "I only have 4 codes, you posted SEVEN (7) different codes." True: does your Scan Tool or software provide a code definition AND an equivalent P-code to the BMW FC? INPA does.

As you can see, a number of BMW FCs have more than one Definition, and checking to see if your scan tool or software provides the CORRECT Definition is key. I'm NO EXPERT in Fault Codes, but I would certainly want to know if I was getting the correct definition, and what are the limitations of the software I am using. There are TWO different Definitions of 2AAC, and THREE different Definitions of 2ADA.

It would be helpful to know what Scan Tool or Software you used to read those codes, what Definitions it provided, whether P-code equivalents were listed, and WHAT the Freeze Frame Data for each code was (engine conditions & mileage when code saved in DME).

I don't have an N51 and am NOT familiar with the Secondary Air System, so cannot do anything but refer you to the correct TIS circuit diagrams for your vehicle. Unfortunately, without knowing your build month/ year, I can't provide correct circuit/ fuse/ relay information as 2007 cars built BEFORE 3/1/2007 used one setup and 3/1/2007 - 8/31/2007 used another. For example, here is circuit diagram for "Secondary Air System" for N51 built between 3/1/2007 - 8/31/2007; if yours was built BEFORE 3/1/2007 you need to drill down and select correct build date:
https://www.newtis.info/tisv2/a/en/e...system/x2O0a1e

If you click on the BLUE component ID# for the Secondary Air Pump Relay, K6304, you can click on "Installation Location" and see that it is found at the lower right corner of the JB on N51 models after 3/1/2007:
https://www.newtis.info/tisv2/a/en/e...lim/1VncFDHYib

If you download the Bentley Manual "Searchable" pdf per the link in the attached "References" you can do a search on any code number (that is listed in Bentley), P-code or BMW FC, and quickly find the definition.

Please give us an update,
George