I am have purchased an 07 GL450 with about 170000 miles and need some guidance with a few issues I am having. I have a few different fault codes and a check engine light on.
P0410 Secondary Air Injection System
P0307 Cylinder 7 Misfire Detected
P0632 Power-train
P0660 Intake manifold tuning valve control circuit(bank 1)
P0814 Power-train Transmission Range Display Circuit.
I replaced 3 coils and all spark plugs a few thousand miles ago. I was getting a misfire on #5 and #7 cylinder. I also replaced the secondary Air pump. After replacing the air pump I cleared the codes and they came back after a week or so. i decided to look into the Air injection valves on the front of the motor. I noticed that both valves had some water in them when I removed them from the engine. I was able to actuate both valves by pulling a vacuum on them. I also checked the check valve for the for the vacuum line coming from the intake and it appears to be working. The main code I am trying to rectify is the air injection code. I am not sure if any of the other codes are related to the Air injection system. Any help is greatly appreciated.

 

Wait, are all these codes current?

0632 indicates the ECU was replaced and not matched to the vehicle.
0814 might be related to 0632.
0660 is probably the tumble flap

You know what 0307 is; the problem with diagnosing the cylinder misfires is they could be due to any number of different causes. If you cleared the code and it returned after having swapped in a known good coil, you have a bunch of tricky possibilities remaining.

What do you know about the history of this vehicle? Not to frighten you, but 170k miles is a long distance in which to accumulate demons.

 

I do not know the history of the vehicle. I know all too well how many problems can arise from 170000 miles. I have attached the a screen shot of the faults I had when my scanner was connected. The vehicle runs ok I was just hoping to be able clean up the check engine light. The coil installed was a new coil. I will probably swap it with another cylinder and see if the problem moves.

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Screen shot from my code reader.

 

The problem is, you are seeing the ghosts in the machine. Now, it's possible these are some weird historical codes, maybe due to some electrical work, but you have to clear them completely in order to be sure. Two of them, as I noted, have to do with the ECU and indicate some significant problems or changes that have not been addressed.

The 410 error means almost nothing. I'd address that last.

The misfire error is a very high-level indicator. It only means that there is an interruption in torque when cylinder 7 is supposed to be producing power. Whether this is due to lack of spark, a bad fuel injector, a leaky valve, messed up piston rings, there is no good way of knowing. If the error isn't bad enough to make it go into limp mode, I wouldn't stress about it right away.

I strongly recommend you start by getting a scan tool. You have an OBD tool; next step is something that reads modules specific to the MB. Icarsoft makes pretty good read tools; guys here get decent results with the MBII. However, it only reads, and cannot send instructions; for that you will need to go to a more advanced tool like Autel, which will set you back $800. You will want at least the Icarsoft MBII to troubleshoot your misfire error; you will need such a tool to clear the errors associated with the ECU to figure out if they are real and current. If your OBD tool can clear pending or historical codes, then be my guest.

The tumble flap is a known problem in the intake manifold. Fixes range from very cheap to ouch. Do your homework on that one.

Since the 0410 is just for emissions, and you changed the pump, I'd worry about that last. It's very strange there was water in the check valves, though. This truck didn't get flooded, did it? I've never investigated the secondary air system, but off the top of my head I can't imagine how water would get in there.

In summary: You need to establish exactly what the current issues are. The bottom three codes are probably the most significant. You have to figure out if they are genuine or from the distant past. The tumble flap can cause problems,which might be the cause of your misfire error. And if the ECU is not matched to the vehicle, you will have to go to MB or a top tier indy to get that straightened out. It is generally risky to leave the system with glitches like that left hanging.

 

I have removed both air valves on the cylinder heads for inspection. There was quite a bit of carbon buildup on the valves and inside of the head. I am working on cleaning eveything while I have it apart. I have tested the the solenoid that actuates the air valves and it doesn't seem to be shifting. I have a new one coming soon. I will reassemble and see if the air injection fault goes away. I may look at taking the vehicle to someone and have them try and flush out the ecm mismatch and diagnose a couple of these issues. Is there way the verify if the ports for the air injections is clear. I cam see down into the head but only about an inch or before the port changes direction. I will keep you posted as to what happens.

 

I have been paying attention to the GL for the nine years since mine left warranty and I figured out I would have to learn to tackle things myself. There is another guy on this forum that thinks he has a blown head gasket. Both that and failure of the air injection valves are issues I have not seen before. Not only that, the air injection system is not necessary for running the motor. You have already burned money on an air pump you apparently didn't need; while it is tempting to work on parts you understand and are sitting right there at the front top of the motor, you could still be barking up the wrong tree - fiddling with the wrong parts.

I had my transmission changed, and driving away from the indy, up pops a 410 error. Took it back and the shop diagnosed needing replacement of the air pump and relay. I said thanks but no thanks and took the GL home after ordering an air pump and relay. Both are still sitting on my shelf after 40k miles. The error has not recurred. It is a suspicious coincidence, and I can only guess that fiddling with the ECU leaves the system somehow prone to misdiagnosing air pump faults.

The drivetrain and computers form an interconnected system that, unfortunately, was not made robust. Case in point: I had a coil failure. I changed the coil, but the limp mode and errors kept recurring. After changing the injector, leaving the truck idling with injector cleaner for hours, changing spark plugs, I finally figured out that the error had to be cleared manually, or let clear over multiple start-run-stop cycles.

Your primary concern is the ECU mating. The fact you have an ECU that thinks the shifter isn't displaying properly, and the odometer display does not match the ECU - whatever is wrong there could easily cascade to other parts of the system. There are gizmos people insert in-line with the display that change it; possibly your GL has one of those installed. Big Clive on youtube did an analysis of how these things work. Although, at a display of 170k miles, you might want to be sitting down when you find out what the genuine figure is.

I'm not sure but I think the MBII can query the ECU to find what it thinks the mileage is.

Once you are confident in the ECU, I would pursue the tumble flap issue. Conceivably that is the cause of your misfire errors.

Note that the order of priority is the opposite of what your OBD tool is telling you. Ignore the big scary red at the top and form your own list of priorities.

Honestly, I think you have the temperament you will need to make good use of this truck. Take good care of it and it will take good care of you. Best of luck.

 

FWIW I have experienced two broken intake manifold tumble flap actuators and I’ve had nary a misfire in 40k miles.

 

It doesn't appear that any of the linkages or actuators are broken on the intake. Does anyone know what type of sensor and the location of the sensor that is triggering the P0660 fault.

 

Looking at the description of the code, I would bet it is similar to a Replace Bulb error: The system is detecting that insufficient current is flowing through the actuator.

Or possibly too much, indicating the actuator is stuck.

 

PO410 is just the air injection pump, easily replaced. See first item in this article


https://blog.fcpeuro.com/the-definit...d-m273-engines

 

I have already replaced the air Injecrion pump and I am still getting the error code. Thanks for sharing the link that was very informative.

 

Last year I had this P410 in my car, I had replaced the secondary air pump with no result, so I took out the bypass valve and cleaned it, as it was very dirty inside. Once the bypass valve was clean, the error code disappeared after cleaning the error codes.

 

I just put everything back together and when I started the vehicle the air injection system never turned on. The fuse is good and a I switched the relay with another one. I also didn't get any vacuum thru the solenoid that actuated the air injection valves. I did also notice I had a cam plug about to fall out. Any thoughts on oem vs aftermarket. Also should replace the pcv valve when replacing the cam plugs.

 

Did you confirm you have no issues with the ECU?

The cam plugs have been discussed numerous time. Search the forum.

 

The only thing I have done with the ecu is clear the codes upon restarting the engine. I will be taking the vehicle to a shop who has a better scan tool than mine after I get the cam plugs replaced.

 

Quit worrying about the air pump, then. it isn't necessary for running the engine, and the faults could easily be somewhere mysterious. When you know everything critical to the operation is good, then circle back to troubleshoot that.

Same goes for the cam plug. Push it back in. Keep an eye on your rear view mirror; if you see a lot of smoke, the plug fell out.

 

The cam plugs will be here on Monday. It is a second vehicle for the wife so I am not in a big rush. I plan on getting it to a shop and try and figure out some of the more pressing issues like the powertrian faults next week sometime.

 

While I agree with Eric that the air pump is not causing any real problems (aside from seteting a Check Engine light which is probably driving you crazy), it's the only thing that I've messed with on your list (but in my case on a BMW.)

My experience was about as frustrating as your on that car. In my case, the pump was good but the CE light was illuminating almost daily. I replaced the valve, thinking that was the problem, but it wasn't. The injection pump just pushes air into the exhaust to help the exhaust gases fully combust until the oxygen sensor determines that the cold start cycle is complete, and then it turns off. This is a combination of an electrical signal (to the pump) and vacuum (which operates the valve.) In my case, though the vacuum hoses appeared to be in tact and in good shape, when I pulled them they were full of cracks and the valve wasn't actually opening. It turns out (a BMW mechanic buddy eventually sent me the troubleshooting info) that the ECU verifies that there is vacuum every time the car enters the cold start cycle, and if not present, set the CE light.

Given the underhood temperatures on these cars, I would replace the vacuum hoses on a 170k mile car. The annoying part is that when you go to the auto parts store to buy hose, you likely won't find the correct metric hose, but the closest SAE equivalent which will be slightly too large a diameter. So you may end up having to special order the hose. I vividly recall getting the auto parts store hose home and routing it only to find that it didn't fit properly on the nipples. At that point, my inner race car mechanic instinctively reached for zip ties which did the trick to allow the valve to pull vacuum. They held for at least 5 years until I sold the car.

 

I took the car to a local mechanic who connected to it with a snap on tool to check the codes. He was able to manually actuate the air pump and the solenoid for the air injection system. He scanned all the modules in the car and didn't find anything specific that was causing the problems I have been having. There was a few references in different modules referencing a loss off communication with the cluster. He cleared all of the faults in all of the modules. The following day he restarted the car, the air Injection system started and the car has been running without any new check engine lights.

 

The Check Engine Light in my 2012 GLK350 4matic has been coming on every winter for the last 5 years. Error code - P0410 (P0814 - Mercedes error code) - Secondary Air Injection System. It only comes on in COLD weather, when the temperature is below freezing, never in summer. I thought that it may be due to ethanol (= water) in the gasoline. I switched to Shell V-Power NiTRO+ 91, which in Ontario, Canada does NOT contain ethanol. After about 4 or 5 fill ups ... problem solved. Check engine light does not come on anymore, even though this has been the coldest January in almost two decades.

 

Unlikely the ethanol free gas fixed the problem. The secondary air injection system is an electric air pump that blows into the exhaust to help give the catalytic converters extra oxygen so they warm up faster. It is probable the air pump and / or relay simply do not like the cold weather. I bet the system that checks it only looks for pump operation and maybe air flow. If the latter, it might be that the cold weather makes those sensors stick.

It is probably just a coincidence that the error code went away with the ethanol free fuel.

If the error recurs, and only occurs occasionally, I would just clear it when it pops up.

Besides that, there simply are not very many components in the system, so it is not difficult to repair.

 

I think that the system that checks it is "the computer uses a Lambda (oxygen) sensor located in the rear of each exhaust manifold, before the catalytic convertor". Ethanol (and Methanol) in gasoline can apparently "skew" the O2 sensor readings. The Shell gas is also "Top Tier", so I'm wondering if maybe (???) the detergents in it had something to do with correcting the problem ? The Check Engine Light has not come on for over 2 months now. I will continue using the Shell Gas and monitor the issue.