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Discussion Starter #1
I know that the p0410 code is set by problems on the secondary air injection system. From what I've read, the checks are normally done on startup.
However, my CEL recently went on twice with a P0410 code - once while the technician was driving the car into the bay for the annual smog check :eek and the second time on the freeway while accelerating. The airpump is running fine during startup, consistently for the same duration, maybe about 90 seconds?

Questions: (1) Are the secondary air injection also tested while driving?
(2) Does the fact that it comes on, while at normal temperature and driving, point to a specific area to check?

The car has a M112 engine.
 

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1 During start up no test is done. After some driving and after some certain conditions are met.

2) Test pre-requisites:

- engine at idle
- vehicle stationary
- air injection pump has been activated 1x after engine start
- no faults with voltage supply to exhaust gas recirculation valve (Y31/1), air pump switchover valve (Y32) and electrical
air pump (M33)
- no faults with exhaust gas recirculation system
- no faults with throttle setting element (M16/6)
- no combustion misfires
- no faults with 02 sensor before catalytic converter, aging
- no faults with CAN Databus
- self adaption of mixture formation not at limit values
- outside air pressure over approx. 780 hPa (since the test will not be done above 8000 ft)
- engine coolant temperature < 90°C
- Lambda regulation released
- A/C is off

Source: Startek
 

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Discussion Starter #3
Thanks mrboca.

I'm not sure if Startek is accurate since during the second occurrence the AC was definitely on (Texas temperature > 100F) and I was driving on the freeway. No misfires (new plugs 1 year ago), new O2 sensors (1 year ago).

The problem seems to come and go during the last 18 months. Sometimes several months pass without any CEL, at other times it would go on more than once a week. I guess I'll have to start checking all possible components e.g. vacuum hoses and ...? My biggest fear is that there might be a blockage in the internal passages - or was that just a problems with the previous generation I6 and V8 engines?

Or maybe just try to get it smogged when it is on a good behavior phase. :wink
 

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I have a scanner which I can connect to the OBD2 port and peek into ECU live data, like whether the air pump is turned on or off. In the flight recorder mode, it records when turned on and off in relation to other data like throttle angle, speed, etc.


Are you sure the P0410 is the only code that is reported ? Sometimes the CEL comes on for some other reason, and there is a pending P0410.

For the test to be performed, the throttle needs to be at CTP, so that you have a stable O2 sensor output. I guess the a/c needs to be off (or may be turned off on demand) to remove the engine load due to compressor running with varying load on the engine.

There may be some electrical monitoring that goes on continuously on the SAI pump relay and the switch-over valve (manufacturer specific P01420, P01453). These may trigger a P0410 also.
 

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I would inspect the vacuum lines and the rubber connectors closely. I recently had the "Engine Electronics" CEL show up, which in this case translated into a P0410 code.

I went through all of the vacuum lines and connectors, and found a very small, almost imperceptible split in one leg of the three way rubber connector between the MAF, vacuum supply and EGR that's at the front of the engine.

And it was on the back/bottom side of the connector, too.

I replaced it and haven't had a code thrown since, and verified this with my SDS as well.

Look for the simple stuff first. Maybe you'll get lucky.

Dan
 

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I had the error code P0410 three years ago (engine M112). After testing the air pump and the vacuum tubing--everything worked/looked fine--I removed and disassembled the shut-off valves. They had carbon buildup, which I cleaned. More significantly, the passages/orifices in the cylinder head were blocked with carbon build-up (one side completely, the other side almost). I cleaned them as best I could with a combination of methods (wire attached to power drill (carefully!), strong vacuum cleaner, spraying throttle body cleaner). After that, I verified exhaust flow from cylinder head ports (running the engine before reassembly), which confirmed that the passages were now free. In the three years since, the code has not returned.
 

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Discussion Starter #7
I went through all of the vacuum lines and connectors, and found a very small, almost imperceptible split in one leg of the three way rubber connector between the MAF, vacuum supply and EGR that's at the front of the engine.

And it was on the back/bottom side of the connector, too.
I started checking the hoses and one of the rubber ones that has a U-turn bend had some small cracks in it. I could not determine if the cracks went right through or whether it was just surface cracks. I did some temporary patchings and if it solves the problem, I'll replace all the rubber pipes.
 

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Discussion Starter #8
More significantly, the passages/orifices in the cylinder head were blocked with carbon build-up (one side completely, the other side almost).
This scenario is my worst fear since it sounds like a delicate and difficult fix.
 

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I would inspect the vacuum lines and the rubber connectors closely. I recently had the "Engine Electronics" CEL show up, which in this case translated into a P0410 code.

I went through all of the vacuum lines and connectors, and found a very small, almost imperceptible split in one leg of the three way rubber connector between the MAF, vacuum supply and EGR that's at the front of the engine.

And it was on the back/bottom side of the connector, too.

I replaced it and haven't had a code thrown since, and verified this with my SDS as well.

Look for the simple stuff first. Maybe you'll get lucky.

Dan
You mean the one in blue circle ?

The one in yellow is the shut-off valve

The one in red is the switch-over valve / solenoid.
 

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It wasn't that difficult, actually. Just one relaxed afternoon, given I was doing this for the first time and extra carefully. A bit of beforehand reading in some threads here helped a lot. This one, for instance:

https://www.benzworld.org/forums/w163-m-class/1407289-help-needed-p0410-secondary-air-injection.html

This one shows the only somewhat tricky issue into which I now remember I ran:

https://www.benzworld.org/forums/w163-m-class/2558665-p0410-removing-air-valve-stem.html

Removing the shut-off valves. (On the picture, the top is already removed, but the lower part with the tube still sits in the cylinder head). The tubes of the valves might already show buildup, but underneath, in the cylinderhead orifice, there is most likely more, so removing them is advisable. Yet initially, the valves will likely not budge (even if the one bolt is removed). Here one has to know that their 'foot' sits not only on top, but inside the cylinder head--with a short stub. Good pictures--and an example of what could go wrong--are here:

https://www.benzworld.org/forums/w210-e-class/2854953-po105-scanner-code-reset-3.html#post16382722

I remember that I succeeded by spraying just a bit of WD40 around the foot of the valve and then using a rubber mallet to hit the top of the tube (not too strongly) so as to make it turn around this stub--first into one direction, then into the other. After a while, it started to move a bit, then I could turn it more easily, and eventually I was able to pull/twist it out.
 

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I've been all through this and I've determined I have no power to the air pump. The relay and fuse I tested initially turned out to be for the starter (I can tell because when I remove it and jump the pins the starter motor kicks in). This was in the fusebox on the passenger side firewall. I have searched every where in the vehicle and the only thing I can find is by removing the cover to the driver's side fusebox it reveals another box with a number of relays and fuses. I cannot find any reference that identifies what each of these relays is for and if one of them is for the secondary air pump. Any help would be appreciated.
 

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Hello:)

You are looking at the wrong fuse panel.

You have not posted the model and model year of the car, but I assume it is 1996-2002.

The fuse is on the fusepanel next to the black starter relay at the passenger side. It is a yellow maxi fuse with 40 amp capacity. The relay is inside the fuse panel module box (or printed circuit board on 1996 / 97 models.

Note that the air pump is only activated during start up with a cold engine for about two minutes. If the engine is warm do not expect the pump to run. It also gets activated during drive cycle but that is of 4 to 5 seconds for testing.
 

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I think I broke the code. The K40 is the relay module in the fuse box on the passenger side at the firewall. Here's a pic. It pops out and then all the wiring connectors have to be removed to set it free. It's between $90 and $120+ depending on where you source it from.
 

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Mr Boca - Thanks for the info. I am now intimately familiar with the operation. I have removed and / or tested the air pump, check valves and changeover valve. Initially I thought the starter relay was for the air pump and it tested good as did the 40A fuse. After going around in a complete circle, I cam back to pump power. At cold start, a voltmeter shows no voltage at the pump connector. Now having isolated the relay, I'd like to test it before replacing it to be 100% certain, but can't find a decent schematic. And yes, I have a 1999 E320 Wagon W210-265 chassis.

Part number for the K40 is 000-540-00-72
 

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I used this schematic for troubleshooting the K40 air pump relay. It tested out OK so I put it back together and the CEL went away. Stuck relay maybe? I'll drive for a while and see what happens. Will report back.
 

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It is the wrong relay module. This one you posted is for the driver's side (K40/2).

The one at the passenger side where the air induction pump relay is K40/4.

Here is the diagram you should be looking at.
 

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Now I've got a BAS / ASR light on that I can't seem to get rid of. Tried re-synching by turning the wheel left then right once then tried it again doing it twice. When starting I hold the break down and after releasing the break pedal the lights come on...
 

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Now I've got a BAS / ASR light on that I can't seem to get rid of. Tried re-synching by turning the wheel left then right once then tried it again doing it twice. When starting I hold the break down and after releasing the break pedal the lights come on...
BAS/ASR has nothing to do with the steering angle sensor you are trying to calibrate. It is for the ESP. Why do you have to press the brake pedal ?
 

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mrboca -

From this thread :


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#3
Jan 27, 2005
RE: Battery Disconnect

Here is a comprehensive list of all items that need (or may need) to be synchronized after loss of power (i.e., battery disconnect):

...Synchronizing ESP:

If the power supply was interrupted (battery
disconnected or empty), the BAS/ESP malfunction
indicator lamp may be illuminated with the engine
running. Turn steering wheel completely to the left and then to the right. The BAS/ESP malfunction indicator lamp should go out....
----------

As for the brake pedal, I always step on it when I start my vehicle and put it into gear. Everything is fine until I release the break either to proceed in reverse or to move forward.

I also double and triple checked all the connections on the K40 to make sure they were all seated properly.
 
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