91RS

So I was driving home today and made a hard turn onto my street and went to get on it and up came service ESP on the cluster and no throttle. I stopped and turned the car off and back on and it still wouldn't go anywhere and then the check engine light came on. Had a P202E (P0120) set. I've searched on here and only see this popping up on C32s. Seeing mainly throttle body or throttle pedal. Anyone had this code on a C55? I was looking at the data with Star but I forgot to push the pedal to the kick-down so I'll have to check that again, but I think it's ok. I wrestled off the damn intake elbow off and disconnected the throttle body connector and the clips weren't broken. I opened and closed the valve by hand and it felt good. I put it all back together and cleared the code and reved it a few times and then it did it again. This car is really testing my everlasting nerve the last few weeks...

cm60k

This is a Malfunction in Throttle Position Circuit or Throttle itself ,,

did you reset the Throttle by the Star, sometimes Throttle send a wrong signal to the ECU & back again to the Throttle,,

if you reset the Throttle & still have the issue, that means need a new Throttle($$hope NOT$$) ......

ZAYED,,

Viper98912

Yea, that's an odd one. Looks like you're looking in the right places

91RS

I didn't do that, I'm still figuring out how to use Star (never done anything but some version coding with it). It isn't very user friendly. Plus, I work on GMs and the wording Mercedes uses for everything is different. The only thing is I really don't want it to do this again, I was lucky (the only "luck" I've had it seems) it happened when I turned onto my street, so I wasn't far from my house. Otherwise, I would have been calling a wrecker. I don't know why people are replacing the throttle pedal though, this code shouldn't have anything to do with that. There goes my header money, I was just about to get this project finished.

Quicktwinturbo

Are u using K&N or Greenfilter? If so, did you recently cleaned them?

91RS

No, I won't use those kinds of filters.

Lenin

Check out the wire harness from the TB. Maybe try one of electrical connection cleaning sprays.

Gramma_Benz

If it happens again, turn the car off for a couple minutes and take out the key. then do a throttle reset, and you should be good to go.


If that still doesn't work, unplug the cable to your throttle body for one minute. Then plug it back in, turn key to position two, wait one minute, then start car.

Good luck!

91RS

I'm fixing to take it back apart and put some diaelectric grease in the connector and cycle it a few more times and then I'll do the throttle relearn and see what that does. I've fixed a few GMs with that.

cm60k

That’s a good idea & i hope it will solving a problem,,

Keep patience & good luck.......

ZAYED,,

91RS

Didn't work. I'm so pissed at this thing right now. It worked until it got heated up and then it set the code again and cut the throttle. I wonder if I could take the throttle body off and take the TPS apart and clean it or if there are 10,000 parts in there that would fall out. I'm going to search that code in some of the other forums with M113s and see if there's anything there. I just have the feeling it needs a throttle body, but they've got to be made of gold or something with the cost of the damn things.

91RS

Wow, there's really not that much on here about this code. I don't know if that's good or bad. But it looks like 50/50 of replacing the throttle body or the accelerator pedal. I'm just not sure how the pedal would cause it without setting a code for itself.

Viper98912

I was just remembering, aren't you s/c'd? Something in there?

91RS

Yes, but the throttle body is the factory one (I even cleaned it when I swapped it over) and all the wiring is the same.

betrezra

I'm having the same issue.

I just ordered another TB to replace.

New from mbparts on line $450.
Used from 150-200.

I've already tried the following with about 4 weeks of success but then prob came up again:
1. pulled plug on TB,
2. cleaned connection with CRC,
3. ran TB function through star..... showed TB function OK.

Car ran fine for several weeks after this..... but then last night same deal... no throttle response.

Since I'm putting in a new TB, I'll take the opp to port the TB flapper bar down.

GL.

91RS

I guess that reaffirms what I thought but didn't want it to be. I guess I'd rather not be stranded somewhere. Did you buy a new or used one? Was the $450 a new MB part or the Bosch replacement? I found the Bosch replacement on eBay for $350 or so. I normally buy OEM parts, but if a $900 part can't make it 43k...

betrezra

91RS -
* My bad, the $450 part from MBpartsonline is a Bosch unit. I thought this was OEM.
* I got a used OEM unit from fleabay for a couple clams. I went used so I can test out porting the shaft myself... If I screw it up... no biggie.
* New unit is $780 on-line best price I found.

A little more input for you from my morning of diagnostics with Star:
1. Hooked up star and saw a throttle actuator code in memory.
2. Ran the diagnostics with star with engine off: Star measures and displays voltage reading from idle to WOT (engine off), it also denotes if kick-down engaged.... all of this worked fine and was in spec.
3. Then ran diagnostics with star with engine running...... you hit f4/f5 to change idle speed via laptop by adjusting throttle blade while car is running... worked fine.
4. Also just for kicks with eng off.... put the pedal up down.. and you can hear the servo on the TB moving full sweep.... like a little robot. So seems nothing obstructing it's path/ops.

With all this said.... I'm guessing I have an intermittant fault of the TB servo, or the wireloom to TB, or connector to TB..........

GRIPE MODE - i've had many domestics/imports and I've never had so many niggling little goofy faults in any car... particularly one with <40K miles> GRIPE MODE OFF.... I still love this car, but you better be a mechanic/troubleshooter to own one of these little beasties

Anyway.... used TB on it's way, I'll port the throttle shaft, CRC the connector, and set it up via star.... and HOPEFULLY be back on my way.

Jeff

91RS

Is your code the P202E-008? After I put the diaelectric grease in the connector yesterday and was letting it sit and run, I did notice the idle increased a little on it's own for maybe a second or two. Mine is definitely intermittant as well, I bet I could go out and the car will work find right now. Between my fuel hose problems before (which hopefully are fixed) and now this, I'm really getting scared to drive the car. I'm starting to wish I had bought the CTS-V or the G8.

91RS

It still bothers me how many people are talking about accelerator pedals and I even saw some people saying engine wiring harness, MAF, vacuum leaks, ECM...

My car also wouldn't respond to trying to command the throttle position with Star, but I don't remember if I was trying to do that before or after the code reset.

91RS

There's also people talking about putting tie-straps on the connectors, I wonder if there's enough space on the connector on the throttle body itself to do that.

betrezra

I do have to admit I do not recall getting a resounding "SNAP!" when inserting the TB connector plug into the harness....... I pulled it loose then re-installed and it took some effort to pull out, but no telltale "SNAP"..

I'll look at it more closely when I get the replacement TB in, and see if there is an easy zip-tie lock fix. I am the king of RIG-ology.

91RS

I know both of the clips on my connector were good when I disconnected it yesterday. I've been talking with Glen, and he thinks the problem is the accelerator pedal.

betrezra

I'll try that next, and will stay posted to your thread.

You paid for all that HP/TQ.... you'd kind of like the TB to go to 100% WOT!!!!!

betrezra

Found this on the other site from Marcus.........
Do you think this is worth a try?
Can anyone confirm this will not change my kleemann tune?



Have you considered resetting the adaptive throttle?
Turn the ignition key to the on (not start) position.
Press the gas pedal to the floor and hold for thirty seconds.
Turn the key to the "off" position (don't remove the key), then release the gas pedal.
Wait at least two minutes for ECU to reset.

91RS

That won't affect the tune at all. I didn't do that trying to fix this problem, but I have done it in the past (Friday before last actually). All that does is reset what the car learns about your driving style. I don't believe that will fix it.