E430 Engine Codes - PeachParts Mercedes-Benz Forum

#1 02-24-2004, 08:51 AM

Well I went to Autozone and they were able to do the diagnostics for me - I have the following codes:

P0170 - Fuel compensation value for bank 1 exceeded the specfied range.

P0173 - Fuel compensation value for bank 2 exceeded the specified range.

P0410 - A malfunction exists in the secondary air injection system.

Is anyone familiar with these? Are they a 'dealer only' fix or can I do it myself? What part or parts do I need to check and/or replace? Should I replace my MAFM and/or O2 sensor?

stevebfl · #2 02-24-2004, 10:30 AM

My vote goes to MAF. I would wait on the P0410 code and see if it returns.

Proper diagnostics would first require monitoring the adaptive numbers to see which are maxed and be sure the intake tubing is intact.

#3 02-24-2004, 10:58 AM

Thanks Steve. I'll go ahead and order and replace the MAF.
Pardon my ignorance. What and where is the intake tubing? Is it a 1/8 od plastic tube near the front of the engine?

stevebfl · #4 02-24-2004, 06:04 PM

No I am refering specifically to the 4in diameter piping from the air mass meter to the intake, but less specifically any intake manifold leak.

Gilly · #5 02-24-2004, 08:15 PM

On the PO410 code, here's a suggestion:
On cold start-up (first start of the day) have the engine hood open before starting. Start car and walk in front of the car. You should here a fairly obvious electric motor sound, almost like a vacuum cleaner is running under the hood. It will quit after about 2 minutes. If this is working you at least know the AIR injection pump works. If you don't notice this running, there is a very large fuse for it in the fusebox you should check. If the fuse is blown, more than likely the electric motor needs to be replaced.

Gilly

#6 02-25-2004, 06:28 AM

Gilly and Steve - thank you for your invaluable help! I ordered a new MAF and will install it when it comes in.

Steve: that tube I mentioned is at the front of the engine under the MB cover. There's a small diameter plastic tube there that has rubber 'boot/fitting' on each end - it sits vertically...well that
snapped, so i used duct tape to reattach it. It's about 4.5 inches long and about 1/8th inch od. What does this go to? (98 E430)

Gilly: Regarding code P0410, I started my car this morning and I heard SOMETHING start up, presuming it was the AIR pump, it sounded like a blower/fan kicked on then stopped after about 45 seconds. I forgot to check the fuse - will do that today.
By the way - where is the AIR pump? Left or right side? How much is the electric motor and can I replace it myself?

You guys are INVALUABLE!!

Gilly · #7 02-25-2004, 07:55 AM

The AIR injection motor is front and center on the motor, right on top, and is easy to change. If you remove the engine trim panel, it's right about under the MB Star, and it's large, you'll see it.
If it runs, I don't think you'll need to replace it though. Unless there is something wrong with it other than the motor (broken "fan" or something like that). Maybe 45 seconds is correct, I though it was more like 2 minutes, I'm probably wrong on the time. There may be some ductwork or tubing that is bad which may cause the code also. I'd concentrate on the mass airflow sensor for now....

Gilly

stevebfl · #8 02-25-2004, 08:22 AM

There are a lot of inter related software issues once certain codes are set. I wish all the strategy was published, but it isn't.

I look for cross similarities when judging codes and the similarity between your codes are that the first codes say that an adaptive limit has been reached. This adaptation is done through O2 sensor monitoring of the final results of the fuel calculation.

The secondary air code is set when the air pumped into the exhaust doesn't drop the O2 sensor voltage to below 40mv in a short time. It is also known that the controller watches the ability of lambda correction to affect the low O2 sensor voltage cause by all the air. There is a possibility of lambda correction strategy change do to the adaptation limits being hit.

I would fix the performance problem first. The seconadary air is strictly emissions and is an intrusive test that is failing using sensors that are in default.

#9 02-25-2004, 08:24 AM

Gilly, Thanks for the informaton. The AIR injector was right under my nose! I pose the same question for steve to you - about that 4 inch plastic tube...it must have something to do with the AIR, as that tube snapped while I was changing the plugs (my gut must have leaned on it). :-)

Would that be the culprit? Would I have to buy a 'system' part just to replace the tube? I used duct tape to reconnect/seal it back up.

Thank you again!

#10 02-25-2004, 08:27 AM

Thanks Steve! I'll change out the MAFM and see if the codes persist. I really appreciate the help and education!

Gilly · #11 02-25-2004, 08:39 AM

Yes, that 4" (LONG I assume, not diameter!) plastic tube MAY be for a switch-over valve that the AIR injection pump uses. (PS there is a reason why the AIR is capitalized, it's short for Air Injection Reaction, I believe).
The usual repair is to simply buy another length of tubing, a dealer should have some. Short of that, another appropriate repair is to find a section of rubber vacuum hose which the proper inside diameter so the plastic tube will slide snuggly into the hose. You may find this at a hardware store or easily at an auto parts store. I doubt the auto parts store will carry the plastic tubing though, you could ask. Can you get to both sides of the broken pipe easily. If NOT, just repair it with the rubber hose idea.

Gilly

PS to you and also Steve: Is it possible the broken plastic pipe is actually a vacuum line which is now leaking vacuum, and this is the WHOLE problem? With the engine running, put you rfinger over one end of the broken pipe and see if you feel vacuum (suction), check both broken ends. Do it before ordering a thing!

#12 02-25-2004, 08:48 AM

Gilly, yes it is a four in long tube. I can get to both ends of it. I'll try to vacuum test and will replace the tube. Thank you!

stevebfl · #13 02-25-2004, 08:51 AM

The tube I am talking about is the tube between the air mass meter and the throttle area. I have had two of these break on 113 engines where the accordian bellows is permanantly attached to the hard plastic. This allows unmetered air.

As Gilly points out any vacuum leak will cause problems with the performance codes. This is why the adaptive limits that are exceeded must be established from the scanner as the first step.

#14 02-25-2004, 08:55 AM

Thanks Steve. I'll make an inspection of the tube while replacing the MAFM.

Yours and Gilly's advice and time spent with me has been priceless. I thank both of you sincerely!!

Gilly · #15 02-25-2004, 09:07 AM

No sweat Charlie. That's why they pay us the big bucks

Gilly