VW Audi Secondary Air Injection Explanation and Diagnostics p0410 p0411

In this video we I show you how the secondary air injection system works. This system works the same in most Volkswagen and Audi vehicles. Vehicle used is a 1999 VW Jetta Mk4 with a 2.0 gasoline engine. If you have a p0410 or a p0411 this video will show you how to isolate the problem and find out which part is at fault. If you found something in this video you can use, please give me a LIKE! Subscribe to my channel for a new video at least once a week.

Tools used: Autel Maxisys Scantool (useful but not necessary), jumper wires for relay testing, Mityvac Silverline vacuum pump (cheaper ones work too).

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[jhenson]

3 minutes in and you already found my problem. Thanks!

[vian]

wow i don't have any problems with my air pump . but it was an excellent video fun to watch.

[seaofgreen]

Bro! U saved me so much time. The CC is g2g!

[RandyPrimeaux]

On the MKIV generation, the Secondary Air Intake Pump runs for about 100 seconds at cold start, then again for ten seconds at the first stop.

[brandonmoreno]

I have a 2000 Jetta 2.0, I’ve tested my smog pump by jumping the Pins on the relay and it work fine no leaks either, and I replace the relay, I checked all the fuses and for vaccume leaks, the code it is throwing is a p0411, my pump does not want to turn on when I’m starting it on cold start or when I turn it off, I even cleaned the grounds and nothing, what am I missing ?

[SpaceXForce]

Here's an EASY TEST you can do to rule some things out:


Find the intake tube of the SAI pump, it's usually directly connected to air intake box. Remove the air intake box if necessary and disconnect it so you can see the open of end of the intake tube.
Now when the vehicle is dead cold and hasn't been running in some time, start the engine, leave it in park with the hood open, and then run around the front and see if the pump turns on.

If the pump doesn't turn on check the fuse and the SAI pump relay in ECU box, typically under the hood or compartment below the steering wheel. The relay terminals sometimes turn black when it's going bad. Also check the wires leading to the SAI pump for damage. If all are good then you may need to replace your pump, but that's typically rare.

If the pump turns on, is there a good amount of suction at the end of the intake tube? There should be. If not, then you either have a bad pump, a clogged or broken intake line, clogged or broken tubes that lead to the exhaust manifold, faulty solenoids that control the combi vales, faulty combi valves, OR worst case scenario, clogged ports in the engine head that exit each exhaust port. That's a very costly or time consuming fix.

If the pump turns on and you have good suction, then that means the ECU is sending signal, intake tube is good, SAI pump is good, but you may have broken hoses OR, a big OR, you may have had a clogged foam filter in your air intake box that the SAI pump intake tube was attached to and by you disconnecting it you actually without knowing fixed the problem. I'd recommend replacing this foam filter as they disintegrate and also clog up overtime.

To rule out broken hoses simply activate your pump manually by applying 12 volts directly to it with the engine off, and seeing when the SAI pump runs that not much air is entering the system.
With the engine off, the SAI system is closed, so the air should have no where to exit and thus very little to no suction even when the SAI pump is running. That's a good sign and that means you don't have broken lines. The combi valves and solenoids could still be bad and stuck in the closed position preventing air from entering your exhaust but that was ruled out when you cold started the vehicle and felt a good amount of suction at the intake tube.

It's all trial and error, but no one ever mentioned utilizing the intake tube as a convenient means of diagnosis. Accessing the combi valves and inspecting all the lines is FAR more difficult than simply power the SAI pump when the system is activated the ECU and when you manually activate the pump with the system off (closed).

Best of luck

[stephenleedeshazo]

You said in the video that these pumps are about thirty bucks nowadays because of the age of the vehicle yet everywhere I've called wants 400-plus

[tomasfernandez]

What a great video I have a1998jetta2.0 but my original relay is#111 I’m going to check that now

[nogarasj]

Hi! This video is really well detail explained.
But unfortunately I have a VW Jetta 2008 and I can’t complete my monitor evap system and secondary air injection.
Any tip would help me out.

[jhenson]

My fuse 43 keeps blowing codes were the ho2s heater control circuit low bank 1 sensor 2. Evap purge valve short in ground, Evap leak detected in system. Secondary air injection system relay ‘A’ malfunction. I changed the Evap purge valve this weekend, checked the SAI relay and it looks clean no scoring, replaced the fuse. Start up was fine. Pump was running as it should. Rpm’s fell back to 750 then I took off down the road. 3 miles later I heard the fuse 43 pop and the CEL and EPC Light came back on.. your thoughts?

[catrachan]

Thanks for this video. I’ve noticed I almost never hear the SAI pump go on lately… usually my cold start is with temps around 3ºC… do you believe a vacuum leak at the SAI valve could be causing this? I’ve been getting poor mpg and I’m thinking it might be a vacuum leak but haven’t found it, the car runs smoothly, no misfires, new spark plugs, oil etc…

[landon]

How do you check voltage in the secondary air sensor from the signal wire?

[TheChrisDam]

I've got P049100, P049200 fault codes for the audi 3.0supercharged TFSI engine. The pump looks good and the hoses too. So I've check solenoid valves and EGR?

[coucouj]

Great video… but what I would also say is at:
@2:28
…this is a 2L engine and what I wanna do realy quick is to clean up all the leaves and weeds in the wiper ecu valey

[johnnycashh]

Thank you, 411 is present while I used my new scanner. Gonna try a few things! 🍺🍺

[johne]

Any tips on how to remove and replace the solenoid switch? My combi valve and air pump pass the test. The relay checks out, as well. (Pump does come on during cold starts or VCDS secondary air readiness monitor routine. I can feel no vacuum from the solenoid switchover valve when the engine is running and air pump is running, which leads me to believe it is not sending vacuum to the combi valve. No pending or actual DTCs, but the readiness monitor never sets. (The others all set quickly and easily with a couple of drives.)

[agustinalberto]

Great video. My new SAI pump turns on intermittently. Replaced 100 relay but still does it. Any thoughts would be great. Thanks

[ivanseniormiletic]

I have problems with Passat 2005 2lite engine no AZM 118010 Secondary Air Injection system Bank 1, Flow Too Low.
Please can you help

[ase]

What system does 1999 early model aeg 2.0? My sons 4th gen 1999 believe did not come with air pump.

[remorlrrlrll]

Have Mk4 02 GTI and have obd eleven pro scan tool and software. Im having trouble getting the secondary air monitor to run.. all others are and no cel codes ...the car runs fine just 80, 000 miles completely stock and maintained... Done most everything and it won't let me force the test.. but can other monitors.