[maxcsr]

Hello eveyone

I have an issue. 2 months ago I was always getting code 2A00 and I took it to mechanic he said that the pump is not kicking in and I need to change the sec air pump.

I held of till my inspection is due this month.
I bought one off Amazon and mechanice put it in for me. I drive next day I have a SES light on.

Now the code coming is different. It is now showing code P140A

What could be the issue? My car driver perfectly no issues with power or anything.

Im running on a very tight budget as I just started school. And would like to find a way to fix this issue and pass my inspection without paying an arm and a leg.

Please help me what should I do to pass inspection with this.

Thanks so much

[gbalthrop]

Originally Posted by maxcsr

... 2 months ago I was always getting code 2A00 and I took it to mechanic he said that the pump is not kicking in and
I need to change the sec air pump... I bought one off Amazon and mechanice put it in for me. I drive next day I have
a SES light on. Now the code coming is different. It is now showing code P140A... I'm running on a very tight budget
as I just started school.

"Mechanics" replace parts. This 'Mechanic' misdiagnosed the cause of the issue. That cost you MONEY that you
didn't need to spend. YOU need to learn how your car works & HOW to DIAGNOSE an issue yourself. Most mechanics
are good at R&R (Remove & Replace). Diagnosis, NOT so much.

2A00 is the "Hexadecimal" equivalent of the P140A "P-code". They are the SAME fault, just a different method of identification.
Refer to BMW Fault Code Lookup; your N51 328xi has the "MSV80" variant DME. Always make sure you look at the correct
Module Variant for YOUR car, as definitions depend on Variant:
https://bmwfault.codes/

That is the best online source I know for getting the definition of a Fault Code, whether P-Code, or "Hex-code":
P140A | 2A00 | DME: Secondary air system | msv80 | Engine electronics
If you click on the Blue View
Hyperlink at the end of the Definition, you get a Fault Information page:
https://bmwfault.codes/XMLDiagView?d...E4NjM0NTEwNQ==

See the Service Notes at the bottom of the page:
1. Remove secondary air-injection valve and clean the passage to Bank 1 (in engine block)
2. Install valve again and run through EOL test. If the malfunction is registered again, repeat steps 1 and 2.

See the attached ScreenPrints from Bentley Manual describing how the Secondary Air System works, & showing the
location of the Check Valve. If you have other questions, please ask. Please let us know how it goes.
George

[maxcsr]

Originally Posted by gbalthrop

"Mechanics" replace parts. This 'Mechanic' misdiagnosed the cause of the issue. That cost you MONEY that you
didn't need to spend. YOU need to learn how your car works & HOW to DIAGNOSE an issue yourself. Most mechanics
are good at R&R (Remove & Replace). Diagnosis, NOT so much.

2A00 is the "Hexadecimal" equivalent of the P140A "P-code". They are the SAME fault, just a different method of identification.
Refer to BMW Fault Code Lookup; your N51 328xi has the "MSV80" variant DME. Always make sure you look at the correct
Module Variant for YOUR car, as definitions depend on Variant:
https://bmwfault.codes/

That is the best online source I know for getting the definition of a Fault Code, whether P-Code, or "Hex-code":
P140A | 2A00 | DME: Secondary air system | msv80 | Engine electronics
If you click on the Blue View
Hyperlink at the end of the Definition, you get a Fault Information page:
https://bmwfault.codes/XMLDiagView?d...E4NjM0NTEwNQ==

See the Service Notes at the bottom of the page:
1. Remove secondary air-injection valve and clean the passage to Bank 1 (in engine block)
2. Install valve again and run through EOL test. If the malfunction is registered again, repeat steps 1 and 2.

See the attached ScreenPrints from Bentley Manual describing how the Secondary Air System works, & showing the
location of the Check Valve. If you have other questions, please ask. Please let us know how it goes.
George

Hi,
I'm confused. So the pump was supposedly working but due to valve on bank1 is clogged prevented it from turning on?
Im confused since I'm not a mechanic or that tech savvy.

When i start my car I touch the pump to see of it kicks in but it doesn't start on cold start.
Will cleaning the valve fix the problem?
So should I tell him to clean behind the valve on cylinder head? That's it?

He also said it could be my oxygen sensors. Is that make sense?
I have to pass inspection this month and I was planning to drop of car to mechanic next week but I'm afraid he will take advantage and start doing things unrelated to the cause of the issue so he can make extra bucks out of me.

Please help me I'm currently a student and running on very low budget for at least another year. Car is driving fine. I just ordered 2 front struts+2 front new tires and will do wheel alignment with him also. He gave me quote for these $700 (I bought the parts on fcp, that's labor).

What should I tell my mechanic to do so he doesn't start digging into unrelated costly repairs?
How much will this cost if you have an estimate or hours needed to do this.

I already paid him last week $100 to swap the pump to the one I got from amazon.

I appreciate your time and effort in helping me to find a solution for this .

Thanks so much

[mainbearing]

Test the air injection pump and make sure the new one is working. Maybe the downstream oxygen sensor is the one used to monitor the pump's performance?

DIY on replacement would have saved you $100. It may be daunting at first, but the air injection pump is relatively easy to replace.

[maxcsr]

Originally Posted by mainbearing

Test the air injection pump and make sure the new one is working. Maybe the downstream oxygen sensor is the one used to monitor the pump's performance?

DIY on replacement would have saved you $100. It may be daunting at first, but the air injection pump is relatively easy to replace.

I will have him test the pump. Is it better I buy the oxygen sensor from fcp euro or just have him buy it instead? Should I change the 2 downstream oxygen sensors? Do you know roughly how much they are and labor/hours needed for it?

Thank you

[mainbearing]

If you buy the sensor from FCP you will get their lifetime replacement policy. Unless the mechanic can give you lifetime replacement you might want to buy them yourself. However, he will probably not give you any warranty on self-supplied parts, and you will have to pay labor each time, even within the typical labor warranty period.

Let the mechanic properly diagnose it first if he can, do not let him throw parts at the problem. Some posts suggested oxygen sensors, others found solution in the hose going from the pump to the air valve. It may be clogged air valve or bad air valve. Also check voltage at the pump harness.

Here are some threads:
https://www.engine-codes.com/p0140_bmw.html
https://www.e90post.com/forums/showthread.php?t=593036
https://www.bimmerforums.com/forum/s...ric-code-P140A

[lookalikehuuh]

I would return the secondary air pump to Amazon and ordering one from FCP Euro, Turners, or Pelican Parts or somewhere that will sell you an Original Equipment (OE) part. Its highly likely that the Amazon part is the biggest piece of junk in the world. Anyway its likely that your original pump may not even be bad.

For the record the local auto parts will also sell you a bunch of junk most of the time.

What I would do here is install the original secondary air pump myself and then go thru the steps that George provided you so you can properly troubleshoot the system.

[maxcsr]

Guys i tested my original pump and it worked when suplied it with power. So the issue is probably one of the 2 ox2 sensors downstream? Right?
I dropped car off this morning to mechanic and told him that pump is working and to check the 2 ox2 sensors downstream. He hasn't called me yet

[Cal122]

Sharing a couple of things on the N51/SULEV model, in case it's helpful.

If your car is within 15 years/150k miles of when your car was sold new (first registration date), this should be covered by the dealer under the SULEV warranty as you're in a SULEV state.

I've heard of the secondary air pump going bad if the valve it's connected to get's stuck, and therefore causes the pump to go bad. Part number for the valve is 11727557909 and you'll see it on the side of the engine where the air pump connects to. That can be disconnected, cleaned and checked out to ensure it's not stuck or filled with carbon.

If all of that and the oxygen sensors check out, the worse case scenario is the internal channel of the engine is clogged with carbon build-up and triggering the insufficient airflow code. Unfortunately I haven't seen many solutions to this since the channel isn't accessible for cleaning unless the engine is disassembled. More info here: https://www.e90post.com/forums/showthread.php?t=2127733

The secondary air pump is only used on cold starts, so the car should run fine, but it will fail an emissions check and that's one of the reasons BMW has the 15yr/150k sulev warranty on these engines.

[maxcsr]

Mechanice just called me and said he put old pump back on and he said he doesn't think its the oxygen sensors because he said he's not getting a code for oxygen sensor.
He told me put "Guaranteed to Pass" in my gas tank on full tank and drive the car couple of days. He said this will clean the oxygen sensors in the back and I will pass inspection.
He said he checked the air and seems to be fine.
But the pump doesn't turn on on cold start.

Does that make sense?

[mainbearing]

As Cal122 mentioned above, do check your SULEV warranty as the problem may still be covered. In that case you will get the problem fixed for free.

If not under warranty, then check to see if the valve is stuck. See with the valve and pump connected, if air passes thru when the pump runs. Anyway, above post 9 for details.

[maxcsr]

I'm out of the warranty since car now has 180k miles.
The mechanic said he doesn't see anything wrong. He said air valve is fine. He said put guaranteed to pass and drive a couple days should fix it.
Im going to pick it up now and do that.

Will guaranteed to pass be harsh on my car?
Car drives perfectly and I have no issues except this

[mainbearing]

If both the pump and air valve are fine, and if the code does not come back then you should be fine.

Maybe he "found" the problem and somehow fixed it. Wink, wink.

If the code comes back then deal with it later. It should be fine now if there is no code.

[maxcsr]

I still have the code 2A00
SES still comes on on the 2nd cold start.
I'm wondering why the pump is not even turning on but when I tested it by supplying it power, it works. But not in car.
Maybe do you think the ox2 sensor maybe the issue?
Im going to put Guaranteed To Pass and see if it works.

Btw mechanice didn't fix it because he said he doesn't see anything wrong and don't know what it could be.

[maxcsr]

I added a bottle of Guaranteed to pass and followed the instructions but I'm still getting code 2A00
The pump is not turning on. I still get SES light on the second cold start.
Now i don't know why the pump doesn't turn on in car but when we tested it outside the car it turned on fine.
Please help me why do you think this is.
I have to pass inspection this month and I only have 10 days left.

I'm worried this mechanic is acting dumb so he can waste some time and money on unrelated issues.
I found it weird he said to put on Guaranteed to pass. Like that should turn the pump magically.

I'm out of the SULEV warranty. What should I do?
If I take it to dealer do you think it'll cost too much?

What should I do I need your help please.
Thank you

[Cal122]

Dealer diagnostics might be pricey, best to find a local independent BMW specialist if you go that route.

Proper way to troubleshoot why the pump isn't turning on is to use a code reader/scanner that has the function available to manually activate the pump. You would hear the relay click and the pump turn on. If it's still not turning on, then move onto troubleshooting the components that are required for it to turn on. Items such as fuse or relays could be bad or even one of the sensors in the car could have a false reading - The pump only turns on if the outside ambient air is above a certain threshold and same with the coolant temperature.

There's a post similar to your issues linked below you might want to check out. It looks like their fix was to replace one of the relays for the secondary air pump.

https://www.e90post.com/forums/showthread.php?t=1896812

[gbalthrop]

Originally Posted by maxcsr

... I'm still getting code 2A00
The pump is not turning on. I still get SES light on the second
cold start.
Now i don't know why the pump doesn't turn on in car but when we tested it outside the car it turned on fine...

Attached is the ISTA ScreenPrint of the wiring circuit for your Secondary Air Pump. There is a Relay, K6304, located in
the E-box. If you have a $10 Multimeter, (HFT or Amazon) you can test to see why voltage is not present at the Pump Connector.
If you need help testing, please ask.

You basically want to check that both fuses, F16 (10A) & F89 (40A) are intact. If so, you then want to open the E-box, locate
the K6304 Relay, as shown in the attached diagram, and if the relay does NOT click when Ignition turned on, cold engine,
Test as follows:

1) Separate the X6304 Connector (at least 8 sockets) from the relay, being careful NOT to contact Chassis Ground;
2) Using Multimeter, Test for Battery voltage at Socket X6304/8, White/Red wire; Red Meter probe contacting metal socket
at X6304/8, & Black Meter Probe contacting good Chassis Ground/metal.
3) Test for Battery voltage at Socket X6304/2, Red wire;
4) If voltage at BOTH those wires (White/Red & Red), then test for continuity to Chassis Ground at X6304/4, Brown/Blue wire;
5) If you have voltage at both Red wires, & Ground at Brown/Blue wire, then the relay is bad. Bench test relay to make sure.
6) You can test the Pump Motor wiring/connector by simply putting a jumper wire between connector sockets X6304/2,
Red wire, & X6304/6, Black/Red/Yellow wire going to pump. Pump should run as long as that Jumper is connected.

Let us know if you need help on HOW to do any test, including bench-testing the relay.
George