barcheta

My 2006 E350 4Matic is not showing me any love. As a proactive measure I decided after 105K that it would be a good idea to change out the plugs.
So off came the coils and in went new bosch oem plugs. All was fine for about 3 days when as i was getting down on it merge into traffic the engine started to sputter and a check engine light. I nursed it over to autozone and had the codes pulled. Initially, it was just a P0304 misfire on cylinder 4. So I ordered a new coild and replaced. The check engine light didn't go out but it did run better for about a day.

Next day as I was driving it started flashing a check engine light again and started to sputter and hesitate really bad. I went out and bought a OBD2 scanner and pulled multiple codes this time. Ordered the rest of the coils and replaced. This had little to no effect and I still seem to be throwing the same codes. I cleared the codes but they came right back... P0300, P0352, P0353, P0356, P2300 P2309, P0301 and P0304. I'm at a loss. It will still start and run but not very well. I'm thinking Cam Position Sensor, but it doesn't seem like this is easy to diagnose.

jcat

Curious, did you gap the plugs prior to installing? And don't tell me they don't need to be checked because anything can happen in shipment.

Other than that, it seems you've thrown enough money for a few diagnostics at an Indy Benz mechanic. My gut says can sensor given its a 350, but could also be crank sensor. I'd suggest you have a qualified pro look it over.

barcheta

Interesting you mention the plugs. I did indeed check the gap.... following one plug I found that actually had a bent electrode on it. Yeah I'm leaning towards the cam position sensor too. Perhaps Starbrite or mbtech can chime in?

I actually talked to my indy mechanic. He confirmed what I've heard on here. A bad crank position sensor would keep the car from starting.

ozusa

(I list your codes and description at the end of this post.)

The P0300, 0301 and 0304 cyl misfire codes are consequences of the other codes' cause. They will go away when you fix the underlying issue(s) that have the coils so upset.

I doubt your cam sensor has anything to do with it. The codes suggest the coils are not getting voltage, not that they are firing at the wrong time, as a crank or cam sensor problem could cause. It is more likely a power to/from the coils problem.

The most specific codes you are getting are the P2300 and P2309. Those each suggest that those two coils, coil "A" and coil "D", are not getting proper voltage (of the 12V kind). Coils B, C and F are not happy either, but are slightly less specific. I suspect they have the same cause as A and D, but that the ODB2 system can't quite tell.

It ain't the coils that are broken. It is more likely the battery, ignition relays and/or the wires feeding the coils 12V have shorted. A grounding problem affecting all coils is possible. It may also be the engine control module or some aspect of ignition control or monitoring.

Is your battery giving good voltage ? If not, some ignition relay(s) may be on strike for the 12V minimum wage and the coils are missing out.

What should you do? I'd get it to someone who can check the primary circuit voltages, ignition control signals, and look for bad ignition relays and wiring gone bad.

I am not a mechanic and I am simply trying to be as logical as my small brain allows. Good luck!

P0300, Random/multiple cylinder misfire detected
P0301, Cyl 1 misfire detected
P0304 Cyl 4 misfire detected
P0352, Ignition coil "B" primary or secondary circuit malfunction
P0353, ditto for "C"
P0356, ditto for "F"
P2300, Ign coil "A", primary circuit low
P2309, Ign coil "D:, primary circuit low

barcheta

Thanks ozusa. The batterys are fairly new. No I do not believe it is the coils either.... or the plugs. I considered that maybe it could be an alternator but I do not see anything indicating low voltage from there. You may be on to something with the ecm or wiring to the coils though. I've heard of others on here replacing the wiring harness to each coil bank. Wouldn't the ignition relay be part of the ecm? or are you thinking it may be a fusable type relay in the fuse panel?

Yeah I think I'm gonna have to pony up and take it somewhere.... my kung fu is weak in this matter.

I live in the people's republic of Maryland... Closer to Annapolis than DC. Anyone know a good MB tech around the Annapolis area. I have used Mitch Carrs before with good luck but those guys are a bit out of the way for me.

vettdvr

I have to wonder what changed. It was well before plugs but after bad.

UMMM are the plugs correct part #?

If so. Are coil packs plugged in. I removed all of mine to get at the plugs and had no problems.

Given random plug miss I still suspect CPS. If the CPS is failing it is basically a Hall Effect device with coil of wire/rotating magnet. This means the coil could partially fail before totally failing. I have seen cars run with bad CPS but not drive away. I have also seen them not start and some of them miss.

Given the cps is common to all of the coils and a relatively easy fix I would consider this before digging into more complex items.

THE CPS is a known high frequency fail part. The other items are not.

If it were my car I would install a new CPS and try again. (this of course is based on the Plugs are correct type, gap,install.)

barcheta

Before I replaced the plugs it ran fine. As I said it was more for preventative maintenance than real need. It ran fine for three days. Then one day as I floored the accelerator to merge into some traffic it started with the check engine light and a sputter/hesitation. I have new air filters in it too.

Yes the plugs are YR7MPP33 Bosch OEM. I checked the gap twice... once when I put them in and again when I pulled them to check them.

I also checked that all the coils were seated and plugged in properly. When you say CPS are you talking Crank position sensor or camshaft position sensor?

ozusa

I agree with Vetdvr that the CPS (Crankshaft Position Sensor) is pretty easy to replace and is worth a try. Remove the air filter, MAF, and there it is held on with one bolt through the transmission bellhousing. It is not hard to do.

I still think that the coils are not getting appropriate signal/voltage. If that is because the management system is bad, poor wiring, or because the CPS is failing, I don't know.

barcheta

CPS ordered from rock auto. I'll let you all know if that was it

vettdvr

Let us know how it works out. Remember the random miss in the codes is the symptom not the cause. The cause is what is common to all cylinders. If it was just one cylinder then you could look at that cylinder for plug/wire/coil.

The CPS IS common to all cylinders.

barcheta

Update: Replacing the CPS had zero effect on the error codes. Still getting multiple codes on multiple coils. Cylinder 1 and 4 followed by P0353, P0355, P0300, P2300, P2309. I've moved coils around... I even swapped back in the old plugs.... nothing.... So I am at a complete loss unless someone has another idea I may not have tried. Looks like a trip to a better equipped garage or the dealer may be in my future. Would a faulty MAF behave this way? I've heard others discuss bad wires. Since they are basically harnesses that plug into the coils would they trigger this kind of condition?

barcheta

Another followup: I ended up caving in and taking it somewhere. An initial diagnostic reveals no spark to cylinder 1 or 4.... plus numerous other codes the OBD2 didn't register. Looks like it may be pointing to an issue with the ECM. Anyone know what one costs?

ozusa

rockauto.com says $421 on a return/rebuild basis

http://www.rockauto.com/catalog/x,ca...%2Bfor%2BSACHS

barcheta

Thanks ozusa. Not getting a warm and fuzzy from Rock Auto or Cardone about going this route. One of the problems in addition to the three+ week turnaround is getting it resync'd to the car after it's rebuilt providing it can even be rebuilt.... Doesn't look like too many shops have this capability. So looks like a new $2100.00 ECM is in my future. Yay me. The unit was dry when it was pulled so no moisture issues or anything like that.

I'm also getting conflicting information. On the one hand, The first place I took it stated that when they were investigating getting a rebuilt unit, most of the vendors said they were starting to get several requests for Mercedes ECMs. On the other hand the dealer I spoke to said that this is the first time he has ever had to look up the part to get info on it.

I'll let you all know if this fixes it once and for all.

jcat

not sure if this is even possible, but with such a HUGE expense involved, can't they test a known-good ECU on your car first before you purchase? To see if it will fix it or not?

barcheta

Unfortunately, no.... The ECU is sync'd to the car via the VIN. You basically have to buy the part before you can use the part.

jcat

they can't sync/unsync as they see fit? Just wondering, because I did something similar on a previous car which was not a mercedes so I can't imagine it's a one and done kind of thing. As in they couldn't repair and reuse your old ecu ever again

barcheta

You offer valid points. Believe me I'd rather not spend the kind of coin I'm dropping on this. At one point they were offering rebuilt units through the dealer. They stopped doing that.... too unreliable. Plus there is no guarantee that rebuilding it will last. As far as it being a one and done thing, there is as much an issue with liability because the ECM controls things like the vehicle alarm system. I had to submit a copy of my registration and drivers license to the dealer to order the part.

I myself think its kind of silly to put a part like this in the engine bay to begin with.... on top of the engine no less where it can cook real well.

vettdvr

I have bought a ECM for my diesel truck that had to be matched to the security system..

WHAT A PITA that was. Cost of ECM,, Locksmith (american truck, who knows who would do MB) Took 4 hrs of computer time for the reprogram.

For MB I don't even want to know the cost. Why can't you buy a VIN matched program loaded at MB direct? You would have to have it installed but the labor is small cost compared to the ECM.

barcheta

Not sure I follow. VIN matched program at MB direct?

barcheta

So ECM ordered....awaiting delivery and installation at my mechanic. I sure hope this fixes things.

ozusa

sorry it's taken so long to get to this point!

barcheta

So.... ECM installed but the aftermarket coils I bought are not playing well with the new ECM. There was a communication error between the coils and ECM with a misfire on cylinder 3. I ended up replacing that with a new OEM coil. No more misfire and the ECM seems to like that coil but not so much for the rest of them. A new set of OEM coils will be installed for the remaining coils. Just so you guys know the original A0001501980 coil has been superceded by A0001502780. None of my old coils played well with the new ECM either, so they are history, The car is running well enough to use even though it has a check engine light. With any luck as soon as I have the remaining coils in all will be right as rain again.

So much for saving a few bucks doing my own work. Lesson learned. Take heed... if its got an electrical connection it may be best to go OEM where Mercedes is concerned.

vettdvr

Somewhere I must have missed something? Changed coils? Not OEM? aftermarket?

New ECM doesn't like coils?

Coil resistance, current flow and response time (Q of the coil if I remember my EE ) is really important on solid state computers. Sorry I missed this in the discussion.

ozusa

I recall that you replaced the original coils in an earlier phase of the troubleshooting. If you kept them, you could just reinstall them and see if the new ECM is happy enough with the old ones?