Yes, I know, there are TONS out there already, I know, I've searched. I've also searched for these codes (P0170 and P0173) and found a few threads. I figured I would start a new thread since it's been somewhat slow around here and also that my situation is somewhat unique (aren't all of them). So, as you all may suspect, I got a CEL up. I run over to the Advanced Auto for them to hook up the scan tool. I get the Fuel Trim Malfunction codes listed above. I'm going to assume more than likely it's the MAF sensor, although I've read in other related threads that it could be a vacuum leak as well. Now, I know a while back, October I think, I had and issue with my CAT's where I had to run to the dealership to have one side of the exhaust replaced. At that same time, the dealership stated that I would need a new MAF sensor and quoted me a TON of money for the job. So, I bought me some MAF cleaner and cleaned it, CEL no more. So now it comes back. I tried cleaning it again, but to no avail (since the light is still on). I also cleaned up the Throttle body again, but this time while it was out, I polished it up some with a dremel and some polishing compound. Once all was hooked back up, I would unplug the MAF, the car would shut off, but I realized it had bigger problems, read the note below. Anyways, after fixing that issue, I still have the CEL. I unplugged the MAF once again, but the car really runs like crap with that thing unplugged, not to mention makes a wonderful "POP" sound when you goose the throttle. I really hope that all this is, is a need for a new MAF sensor as I have inspection due up next month and the car will not pass Emissions with CEL up. Well, I think that sums that up, unless you all want to hear about the other little problems with the car. Oh, I know, really long post, so if you read all of it, thanks!



NOTE: If you remove the butterfly/throttle plate (whatever you want to call it) make sure it goes back into the throttle body evenly, I didn't do this and when I started up the car, I heard popping and the idle jump up in speed. The ESP Malfunction Visit Workshop appeared on the MDS and the car would only rev up to about 3,000 RPM's. Apparently the throttle body does some sort of synchronization when the key is set to the No. 2 position (not started), I watched it as I plugged it in and started the car while I had the TB sitting on my wipers. So I had to take the TB back out and re-adjust the throttle plate within the TB, what a pain in the @$$. What appeared to be happening was, it was jamming itself against the walls of the throttle body since it wasn't in there completely even, although the two screw holes matched up and threaded up with no problem.

 

Fuel Trim problem both banks. Almost certainly MAF
Check vacuum lines
How old is your fuel filter?
Could be O2 sensors but the likelyhood of both sides going at the same time on a V6 is slim indeed.

 

Wow man, quick reply!

Yup, both banks. I've never checked the vacuum lines, so I'll do that either tonight or tomorrow. Can a fuel filter cause this??? It's still the original one on the car, but I have a Bosch replacement for it, which is basically same as stock. I just haven't put it on yet. Should I replace the fuel filter before buying and replacing the MAF sensor?

That's what I figured and also ruled this out as a possibility.

 

Are you using stock air filters?

 

Yes. Entire car is completely stock.

 

How many miles on the car ?

 

Since it's a 2001, I see no harm in going ahead and replacing the MAF anyway, even if it doesn't clear up everything, from a preventative maintenance standpoint. It sounds like the problem to me, though. I got mine from Autohaus AZ, btw. And it's a 15-minute job; you'd be surprised how easy it is - we could even do it at the NJ meet on the 31st.

 

Sorry, I should have specified that, and known better. 74,xxx.

True. I too order my parts from Autohaus AZ. I got my Behr radiator there, oil filter and fuel filter from them also. I will probably order one up soon. OT, but where is the meet on the 31st? I won't be able to make the boat trip this weekend, so I'd like to do the 31st. Wait, is that the Barbeque meet?

 

¡Si, señor!

 

I was having a very intermittent (maybe once a week) 'stumble' at idle for a couple of months and then the CEL lit up. I cleaned the MAF and installed a new fuel filter at the same time. When I removed the old filter and poured the captured gasoline into a pan a bunch of fine black sand like residue came out. That was about a year ago and no hiccups since.

 

Yes - Please replace the fuel filter immediately!!!

Also & this is something I need to start drumming into people on this forum - we have decided that the O2 sensors are OK and we have no O2 codes - Please never use any silicone containing sprays under hood. If silicone gets ingested into the intake system it will immediately poison & destroy the O2 sensors

 

Pete... I had my first MAF issues around the same mileage you have right now. I hate to admit, but I feel like these things have a max lifetime of 80k miles.... and a min lifetime of under 10k... lol. Replace the fuel filter as suggested - its a fun DIY too

Keep us posted.

 

Will do, once I get some time and some new hose clamps, I'll jump on it!

Will do, and thanks for your prior experience! I appreciate everyone reading through that looooooong first post.

 

Nope, I haven't replaced the fuel filter yet, I had a long (sorta) trip planned this past weekend, headed out towards Pittsburgh. I did however get my new MAF sensor in the mail and installed that. I also cleared the codes. Well, while out by Pittsburgh, about 5 min. from my destination, the car starts acting up, as in bucking on acceleration and idling rough, oh, and the CEL came on. It also, while stopped, shuttered and stalled. Yikes. I'm leaning towards one or a couple of a few things, the throttle body went, the TPS, or something else that I wouldn't even suspect. I have an appointment with a local MB shop (I've heard a lot of good things about this place, plus I spoke with the manager and bought Trans fluid from this garage) to check out the car. I figured he would be able to accurately locate the problem and let me know what's going with this thing. Again, I'll keep ya'll posted. Oh yeah, I'm also gonna see if this guy can't diagnose the ESP problem also.

 

Could also be fuel pump - can you hear it running? Do that filter. CPS?

 

So, I get a call this morning from the Independent MB shop I took my car to. Turns out to be the "Throttle Valve Actuator", or the Throttle Body. Basically, they told me that with their diagnostic tool, they tried to manipulate the throttle valve actuator and got no response from it. Therefore, that's what their pointing to. The quote for the part? $1,100! Sooo, I'm not going to go that route. Anyone have any sources for a new Throttle Body for a C320? I'd love to get the 74mm throttle body that TVT was offering, but they don't have any left, at least the last that I heard. So that being the case, if I'm forced to buy a NEW throttle body, would I HAVE to go with the stock one for the C320? When I had it out previously, I measured the opening, it was 68mm. Could I buy a NEW one for say, a 4.3 (M113)? Or is the compatible 74mm from a 5.0 engine? I don't know what to do. Any suggestions would be appreciated.

 

I have no experience of larger throttle bodies on this engine but it's interesting that Phil's car has just required a new TB thanks to a malfunctioning actuator.

 

I have no experience of larger throttle bodies on this engine but it's interesting that Phil's car has just required a new TB thanks to a malfunctioning actuator.

 

You wouldn't happen to know where Phil got his new TB would you? Or how much he paid? PAGING Phil!

 

I got it for a steal. One of my friends had an extra brand new TB just laying around (he was going to port it out but just decided not to anymore) so I got it from him.

That's crazy, but your TB went out a lot later than mine did...

Sorry, I couldn't help you Pete.

 

It's all good! Thanks for the fast reply too! You lucked out, which is great for you. I'll figure something out. I think I may try to call Anthony at TVT tomorrow to see if he has any Stock TB's laying around from the 3.2 engine. That or try to order one online somewhere.

 

Okay, picked up the car today and got the readings back from the independent shop. Here's what they gave me:

P2004 - Hot Film MAF (Probably cause I had it unplugged, otherwise, it's a new sensor)
P2006 - Air Intake Sensor (No idea?)
P0120 - Throttle Valve Actuator (Figured this was the main problem)

ESP:
C1000 - ESP Control Module (Again, no idea)
C1022 - CAN comm. with Engine (Was told this was from the throttle body not working, hence the ESP error as soon as you start the car)
C1140 - Steering Angle Sensor (I know what it is, but I'm guessing this code is stating that it is malfunctioning?)
C1202 - BAS Release Switch Plausibility (No idea?)

At this point, the shop cleared all the codes and started her back up again. Here is what they got after clearing all the codes.

P0120 - Throttle Valve Actuator
C1022 - CAN comm. with Engine

What they had to say on the write up: Check data stream info. Activate throttle valve with scanner, no movement (scanner?). Check resistance to ME control unit. Must replace throttle valve actuator to continue testing.

So, that's what I have to show for my car as of now. I have a NEW TB on it's way which I'm going to install once it gets to my house. PLEASE, if anyone can shed some light on ANY of the about info provided, I would be thankful! Thanks!

 

Trouble with Fuel mapping, CPS & Cam position sensors can all throw up all sorts of CAN rubbish. Concentrate on the Throttle body & MAF. Sounds as though the Throttle Actuator has snuffed. 2004 can also result in 2006.

I suspect there is nothing wrong with the steering angle sensor or the rest. Turn the cars steering lock to lock 5 times. This will reset the steering angle sensor.

Replace the throttle body & clean & plug in the MAF. Allow a while to adapt & then look for codes. I'll bet there won't be any.

 

Okay, latest update, I'm some what pissed off. I received the brand new Bosch Throttle Body today via UPS from Autohaus AZ. I installed it in the car, put everything back together, and it still doesn't run right! Still the high idle of around 1500 RPM and will only rev up to about 2000 RPM. Also getting the ESP light as soon as I start it up. Unbelievable! Here is a picture of the new throttle body, right out of the box. $440 for the TB, $207 for the diagnostics from the independent shop which told me it was the TB and still a non-functioning car.

EDIT: Check this out, courtesy of Buellwinkle's site(thanks man!), the MB DTC for P0120 isn't even the "Throttle Actuator" as the independent shop told me it was and as it shows on the work order. Now, what? Replace this sensor too? Should I go back to the shop and complain?

P0120 Throttle/Petal Position Sensor/Switch A Circuit Malfunction

 

Here's what my DTC codes from OBDII say:
P2004 = Intake Manifold Runner Stuck Open Control Bank 1
P2006 = Intake Manifold Runner Stuck Closed Control Bank 1
P0120 - TPS/Pedal Position Sensor A Circuit Malfunction
Is that the drive by wire sensor in the gas pedal?