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P0411, hose replaced...bad combi-valve/air pump?

143K views 57 replies 24 participants last post by  wobcc1722 
#1 ·
The CEL on my 2000 1.8T came on a few weeks ago. Pulled P0411 (Secondary Air Injection Incorrect Upstream Flow Detected ) from the computer. Checked here and found that it could be the vacuum hose, combi-valve($$), and/or the pump($$$).

I replaced the hose, which looked suspect, cleared the code but it came back after a few days. I don't think the pump is coming on any more after a cold start (used to be quite noisy, IIRC). If the pump is not coming on any more, it would mean a dead pump or blown fuse, right?

Some questions:

1) Where is the air pump fuse?
2) If the pump is dead, what are the chances that the combi-valve is dead also?

I will check under the hood once the temperature warms up a bit (been -20C for days). Just preparing myself for the coming assult on my wallet...

Thanks
 
#37 ·
A bad combi valve won't cause the fuse to blow... directly. It can kill the pump and the pump can blow the fuse. Because these parts are so crazy expensive, you may want to spend some time testing before ordering. Try powering the pump directly from the battery with jumper wires. See if it spins up and sounds normal. See if it overheats the jumper wires (sign of too many amps flowing). The wire in the harness powering the SAIPump is about 10 gauge.

Were/are you getting any trouble codes for insufficient SAIP flow?

http://www.passatworld.com/forums/6...u-test-combi-valves-n112-solenoid-valves.html

http://www.passatworld.com/forums/42-volkswagen-passat-b5-discussion/319096-combivalve-innards.html
 
#38 ·
Thanks Steve, awesome write-ups!! The last time I heard the pump spin up it was sounded like a jet.

From a VagCOM:
16840 - EVAP System: Very Small Leak Detected - P0456 - 001 - Uppler Limit Exceeded - Intermittent
16795 - Secondary Air Injection System: Incorrect Flow Detected -P0411 - 002 - Lower Limit Exceeded - MIL ON
18613 - Performance Malfunction inCooling System - P2181 - 008 - Implausable Signal - Intermittent
 
#39 ·
Give it the "jumper wire test". From your descriptions, I'm guessing it'll prove bad. Likely a sticking combi valve too (cause for the pump dieing). You can try some of those tests (blowing into the supply hose) to see if that path is open when it shouldn't be. That'll confirm a sticking combi.

P0456




P0411 Your SAIP and combi are causing this.

P2181 could be a bad CTS or bad thermostat
 
#40 ·
I just pulled the pump, it was filled with water. Lukily Thursday I ordered a pump, Combi, Sending unit and a few other items from GermanAutoParts.com They showed up today. I also ordered a timing belt kit from Blauparts.com that I believe comes with a new thermostat. I haven't opened the box yet. I did however plug in the new pump (I wanted to make sure I didn't have an electrical problem before I took everything apart) and she fired right up. So now I'll be busy tearing down and and then putting back together :)
 
#43 ·
So I recently got the saip check engine light. No weird noises at idol but upon acceleration I get a high pitched whistling noise that gets louder as I accelerate more.

I replaced all of my vacuum lines.

Is this a common symptom of a bad combi valve or pump?

If the relay was bad and causing it.to.not work, would it still create the whistling noise?
 
#44 ·
2003 1.8t according to your profile.
What trouble code numbers is it generating? (list all of them)
List all modifications.

The SAIP only runs for a brief time after a cold-start. If you stand near the passenger front corner of the car during a cold start you should be able to hear it kick on and run for about a minute then kick off and go silent. It may kick in a second time for a shorter cycle.

Whistling after warm up when you get into the throttle heavy is probably not a SAIP issue. Some boost leaks can whistle. A boost-leak-tester will find those for you.

A high pitched sound like a dentists drill during boost can mean a bad/dieing turbo.
 
#46 ·
That code has nothing to do with the SAIP. It's an EVAP system code.

As you know, gasoline readily evaporates. The EVAP system contains, collects and stores those fuel vapors so they aren't released into the atmosphere. When the engine is running the system purges the stored vapors into the intake where they get burned. The system checks itself a couple different ways and if it finds something out of order, it pops a code.


P0441- EVAP Emission Control Sys: Incorrect Flow
Possible Symptoms

* Malfunction Indicator Light (MIL) active

Possible Causes
* Evaporative Emission (EVAP) Canister Purge Regulator Valve (N80) faulty/jammed
* Evaporative Emission (EVAP) Canister Purge Solenoid Valve (N115) faulty/jammed
* Evaporative Emission (EVAP) Canister Sealing faulty
* Pipes between Tank Breathing and Throttle Body leaky/blocked

Possible Solutions
* Check Evaporative Emission (EVAP) Canister Purge Regulator Valve (N80)
o Perform Output Test
* Check Evaporative Emission (EVAP) Canister Purge Solenoid Valve (N115)
* Check Evaporative Emission (EVAP) Canister
o Perform Basic Setting
* Check Pipes between Tank Breathing and Throttle Body

Special Notes
* When found in the NAR 1.8T Audi A4 1.8T check TSB 24-08-78 or 2010268/3 or Pass-Thru equivalent TSB
* When found in the NAR 1.8T VW Passat 1.8T check TSB 01-09-09 or 2005554 or Pass-Thru equivalent TSB
o Note: The Passat 26E5 or "R5" recall includes the same software update
* Make sure the quick release lines for the N80 valve and vacuum line to LDP are not crossed.
o This can also make the engine hard to start after filling up the fuel tank.
 
#50 ·
P0411 - Secondary Air Injection System: Incorrect Flow Detected

Possible Symptoms
* Malfunction Indicator Light (MIL) ON

Possible Causes
* Fuel Pump Relay (J17) faulty
* Hoses/Pipes to/between Components faulty/clogged
* Secondary Air Injection Pump (V101) faulty
* Secondary Air Injection Pump Relay (J299) faulty
* Secondary Air Injection Solenoid Valve (N112) faulty

Possible Solutions
* Check Fuel Pump Relay (J17)
* Check Hoses/Pipes to/between Components
o Check Secondary Air Injection Hoses/Pipes for Carbonization
* Check Secondary Air Injection Pump (V101)
* Check Secondary Air Injection Pump Relay (J299)
* Check Secondary Air Injection Solenoid Valve (N112)



The system will test itself by running a short SAIP cycle sometime after the initial cold-start cycle. I don't know exactly when this test is done but it's after the O2 sensors heat up and come on-line. The system goes active and the ECM looks at the primary O2 sensor data expecting to see the extra oxygen being pumped in by the SAIP. If it doesn't see what it expects that means something is wrong with the system. Many things could cause this code. Could be the pump not pumping air or the supply hoses not delivering the air or the combi valves not passing the air into the heads.
 
#53 ·
My 2004 1.8T 4 motion CEL came on with code P0411. For the last while, at cold start up, it has sounded very noisey, almost like a deisel but after a minute, it settles down and idles normal. Is the purpose of the SAI system purely for emissions. If so, I live in an area where emissions is not part of our annual inspection, will running a faulty SAI system cause other problems?
 
#54 ·
The failed SAIP system can cause the CEL to be on all the time. With that light always on, you won't be notified if another problem somewhere else calls for the CEL to come on (because it is already on).

Check the hose from the pump to the combi valve. If that path is broken open, when the combi opens during the SAIP cycle, exhaust pressure and noise can come out of that broken hose. This might be the cause of your engine sounding like a diesel during the first minute of cold-start. And also the cause of your P0411.
 
#58 ·
is there a post with directions on how to replace, i did a Google search but nothing came up. I really don't want to take it to garage if i can do it my self. In looking at it, where the hose connects to the pump is pretty easy. Where it connects to the metal tube up top is pretty tight, is there a tip/trick to accessing it (w/out removing the whole front end)
 
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