|
Indiana Drew
Expert
Date registered: Feb 2007
Location: Houston Tx
Vehicle(s): 2002 G500 LWB, 1980 280GE SWB (Sold), S500
Posts: 2223
| Pedal Value Sensor Error MBUSA G500
Twice over the last 12 months I have been driving at highway speeds 65+/- and have accelerated to pass (I gather triggering the kick down ...) and have found that my engine has died. At the recent occurrence I took it by my shop to have the codes read. The result was a code to this effect: Pedal Value Sensor outside values ... Anyone else ever had this? |
|
| |
|
W5YK
Extreme Veteran
Date registered: May 2006
Location: San Diego
Vehicle(s): 2002 G500, Unimog U2450,
Posts: 543
| RE: Pedal Value Sensor Error MBUSA G500
I get it nearly every time I put the pedal to the floor hard. The vehicle then goes into limp mode. Resets when you turn off and on again.
I haven't figured out a convenient place to tap in and check the pedal value sensor. |
|
| |
|
Indiana Drew
Expert
Date registered: Feb 2007
Location: Houston Tx
Vehicle(s): 2002 G500 LWB, 1980 280GE SWB (Sold), S500
Posts: 2223
| RE: Pedal Value Sensor Error MBUSA G500
W5YK - 4/7/2011 11:16 AM I get it nearly every time I put the pedal to the floor hard. The vehicle then goes into limp mode. Resets when you turn off and on again. I haven't figured out a convenient place to tap in and check the pedal value sensor.
I wonder if it is a part common to more than the G or if is was a new part in 2002 - yours is an '02 isn't it? How many miles do you have on it? The first time it happened I was able to switch off the key and then restart it an continue, the second time I had to pull off and restart it. I would say that it has happened under a hard acceleration where i have back off for a second and then put the pedal down hard again ... Compared to how yours sounds, I'm less concerned, but still it is to a degree a safety factor ... Any idea how much it is to replace? |
|
| |
|
4x4Cal
Veteran
Date registered: May 2007
Location: Calgary, Canada
Vehicle(s): a Desert Silver & a Brilliant Silver G500
Posts: 260
| RE: Pedal Value Sensor Error MBUSA G500
I had the same issue. I then received a hint from Vlad to replace the Accelerator Pedal Value sensor then everything is good after. Greatness.
PS. There was a small spring attached to the unit. When I looked into it was broken because of rust. I ordered a new spring for it as well.
Cheers, |
|
| |
|
Roly
Elite Veteran
Date registered: Apr 2006
Location: Australia
Vehicle(s): 1999 G500
Posts: 661
| RE: Pedal Value Sensor Error MBUSA G500
http://www.mercedestechstore.com/pdfs/508%20Systems%20II/508%20HO%2...
Some useful information about the system here. |
|
| |
|
DUTCH
Administrator Doppelgänger
Date registered: Apr 2006
Location: US, GA, Atlanta
Vehicle(s): 2015 Audi Q7 3.0 TDI,2018 Sprinter
Posts: 9963
| 2000 G500, Too
I had it happen once with my 2000 G500. I replaced that drive-by-wire sensor; and it has not happened again. From what I've heard, it not an uncommon problem. |
|
| |
|
G-AMG
G-Class DIY Host
Date registered: May 2006
Location: South Texas
Vehicle(s): '04 G55, '80 280GE, '99 S420, '98 E320, 2011 E350
| Re: Pedal Value Sensor Error MBUSA G500
Drew, I'm curious, when you found the codes, did they "Re-Adapt" the Sensor, while they were there?
Recently, my wife's G55 had a fuel hose failure, and the engine became fuel starved and quit.
After repairing the line, I noticed when I "Floored" it... Nothing would happen. A STAR interrogation showed a Throttle Sensor fault.
Upon "Re-Adaptation" of the Throttle and Ring Gear Sensor, the problem was solved... no further issues.
G |
|
| |
|
DUTCH
Administrator Doppelgänger
Date registered: Apr 2006
Location: US, GA, Atlanta
Vehicle(s): 2015 Audi Q7 3.0 TDI,2018 Sprinter
Posts: 9963
| Re: Pedal Value Sensor Error MBUSA G500
G-AMG - 4/7/2011 4:31 PM
Drew, I'm curious, when you found the codes, did they "Re-Adapt" the Sensor, while they were there?
Recently, my wife's G55 had a fuel hose failure, and the engine became fuel starved and quit.
After repairing the line, I noticed when I "Floored" it... Nothing would happen. A STAR interrogation showed a Throttle Sensor fault.
Upon "Re-Adaptation" of the Throttle and Ring Gear Sensor, the problem was solved... no further issues.
G
When I replaced the one on my 2000 G500, I did not have to adapt or re-adapt anything. |
|
| |
|
Indiana Drew
Expert
Date registered: Feb 2007
Location: Houston Tx
Vehicle(s): 2002 G500 LWB, 1980 280GE SWB (Sold), S500
Posts: 2223
| Re: Pedal Value Sensor Error MBUSA G500
G-AMG - 4/7/2011 3:31 PM Drew, I'm curious, when you found the codes, did they "Re-Adapt" the Sensor, while they were there? Recently, my wife's G55 had a fuel hose failure, and the engine became fuel starved and quit. After repairing the line, I noticed when I "Floored" it... Nothing would happen. A STAR interrogation showed a Throttle Sensor fault. Upon "Re-Adaptation" of the Throttle and Ring Gear Sensor, the problem was solved... no further issues. G
All we did was clear the fault code and then try and recreate it in the shop without success ... Sounds like dropping in a new one is the key ... |
|
| |
|
W5YK
Extreme Veteran
Date registered: May 2006
Location: San Diego
Vehicle(s): 2002 G500, Unimog U2450,
Posts: 543
| Re: Pedal Value Sensor Error MBUSA G500
I did a bit more investigating of this today.
I found that the cable from the foot pedal to the sensor was adjusted way too tight. In fact it was preventing the pedal being depressed fully, making the downkick just barely possible i.e. the cable was so tight at the end that the pedal could not move far enough down to reliably hit the downkick switch.
It is easy to adjust the tension - there is an adjustment where the cable enters the mechanism around the sensor. You can do it by hand. Screw the nut inwards towards the sensor, so the cable becomes more slack.
With the Star system hooked up, it showed that the sensor was basically OK, but if the foot pedal was pressed really hard, beyond the kickdown, then the voltage from one of the two sensors would go just slightly above the max allowed (4.83V). By slackening off the cable, I could get it to where pedal-to-the-floor would not pull the sensor that high.
Probably should replace the sensor sometime, it shouldn't go out of range like that, even with full pedal.
The WIS mentions adjustment screws for setting the end stops for open and closed throttle positions for the cable, but I couldn't find any on mine.
Edited by W5YK 4/17/2011 11:11 PM
|
|
| |
|
Indiana Drew
Expert
Date registered: Feb 2007
Location: Houston Tx
Vehicle(s): 2002 G500 LWB, 1980 280GE SWB (Sold), S500
Posts: 2223
| Re: Pedal Value Sensor Error MBUSA G500
I just got a new one in the mail ... $136 plus shipping ... When we replace it, I'll check about the cable ... We could not get it to throw a code when it was on the STAR in the shop ... |
|
| |
|
fernweh
Date registered: Apr 2006
Location: Calabasas, CA - Centenario, BCS - Luebeck, Germany
Vehicle(s): Few Mercedes-Benz, a Toyota Amphibious and a Vespa
| RE: Pedal Value Sensor Error MBUSA G500
Similar thing happened to me on one of my last trips down the Baja.
On the long grade down the mountains towards La Paz, I had to pass by a military vehicle which was going actually pretty fast......
Floored the pedal due to oncoming traffic and when I wanted applied power down the line again nothing would go.
I rolled almost to a stop just before the last inspection station and the engine would not respond to the throttle. I wondered how to make it to Harald's place just in idle rpm.
That never happened to me before or after this time.
Interestingly, I found out, by using the cruise control's acceleration switch, I was able to get going again - but still no foot pedal response.
At the compound, I did an AEG - ausschalten, einschalten - gut
Karl |
|
| |
|
4x4abc
Date registered: Apr 2006
Location: La Paz, Baja California, Mexico
Vehicle(s): 02 G500
| RE: Pedal Value Sensor Error MBUSA G500
translation Karl to English:
ausschalten, einschalten - gut = switch off, switch on - good |
|
| |
|
Indiana Drew
Expert
Date registered: Feb 2007
Location: Houston Tx
Vehicle(s): 2002 G500 LWB, 1980 280GE SWB (Sold), S500
Posts: 2223
| RE: Pedal Value Sensor Error MBUSA G500
4x4abc - 4/17/2011 9:32 PM translation Karl to English: ausschalten, einschalten - gut = switch off, switch on - good
The first time it happened at Hwy speed and used the ausschalten, einschalten - gut and was able to restate without slowing down. The second time I ended up restarting on the side of the Hwy - not sure why it worked while rolling the first time and not the second ... |
|
| |
|
zimm
Elite Veteran
Date registered: Feb 2010
Location: pittsburgh
Vehicle(s): lx470, 76 fj40, 72fj40, 96 gelandewagen g320.
Posts: 788
| Re: Pedal Value Sensor Error MBUSA G500
W5YK - 4/17/2011 9:25 PM
With the Star system hooked up, it showed that the sensor was basically OK, but if the foot pedal was pressed really hard, beyond the kickdown, then the voltage from one of the two sensors would go just slightly above the max allowed (4.83V). By slackening off the cable, I could get it to where pedal-to-the-floor would not pull the sensor that high.
while i was reading this, the specter of drive by wire unintended acceleration came to mind, and i was wondering if the system is just programed to shut down if it gets an odd reading as a safety precaution. |
|
| |
|
fernweh
Date registered: Apr 2006
Location: Calabasas, CA - Centenario, BCS - Luebeck, Germany
Vehicle(s): Few Mercedes-Benz, a Toyota Amphibious and a Vespa
| Re: Pedal Value Sensor Error MBUSA G500
W5YK - 4/17/2011 6:25 PM
I did a bit more investigating of this today.
I found that the cable from the foot pedal to the sensor was adjusted way too tight. In fact it was preventing the pedal being depressed fully, making the downkick just barely possible i.e. the cable was so tight at the end that the pedal could not move far enough down to reliably hit the downkick switch.
I do believe, I was never able touch that switch with the pedal.....
Thanks Richard!
I remember, when we were all younger - the first thing when getting a different (older) car, was to check the throttle and make sure that baby would get the big butterfly wide open - VW bug 34HP........
Karl |
|
| |
|
W5YK
Extreme Veteran
Date registered: May 2006
Location: San Diego
Vehicle(s): 2002 G500, Unimog U2450,
Posts: 543
| Re: Pedal Value Sensor Error MBUSA G500
while i was reading this, the specter of drive by wire unintended acceleration came to mind, and i was wondering if the system is just programed to shut down if it gets an odd reading as a safety precaution.
Yes, its properly designed. The sensor has two completely independent potentiometers. They have to agree with each other or else the engine goes into limp mode. Also there are multiple springs on the mechanical linkage, so one of them failing won't matter.
Of course, nearly all of those unintended acceleration events are caused by foot-on-wrong-pedal. |
|
| |
|
W5YK
Extreme Veteran
Date registered: May 2006
Location: San Diego
Vehicle(s): 2002 G500, Unimog U2450,
Posts: 543
| Re: Pedal Value Sensor Error MBUSA G500
fernweh - 4/17/2011 9:18 PM
I do believe, I was never able touch that switch with the pedal.....
I think mine has never worked until today. That cable was very tight. When I put my foot into it hard, the cable would pull the sensor to the limit, and then the bracket holding the sensor would be flexing under the strain. Bad design. The stop limit should be on something solid.
The kickdown switch was not reached until the sensor bracket was already flexing under the strain. I'm not sure I ever reached it in normal driving. |
|
| |
|
fernweh
Date registered: Apr 2006
Location: Calabasas, CA - Centenario, BCS - Luebeck, Germany
Vehicle(s): Few Mercedes-Benz, a Toyota Amphibious and a Vespa
| Re: Pedal Value Sensor Error MBUSA G500
W5YK - 4/17/2011 6:25 PM
The WIS mentions adjustment screws for setting the end stops for open and closed throttle positions for the cable, but I couldn't find any on mine.
Richard,
I just adjusted my pedal position - not sure if I like it that way.
The throttle cable's outer sleeve has the adjustment screws. In order to lower the foot pedal - so it is able to depress the kick-down switch - you have to turn in the adjustment screw below the throttle sensor. That loosens the cable and lowers the pedal position. The second screw sits above the pedal where the cable goes through the firewall. Adjust that so there is still a bit of play in the cable.
Also when looking at the throttle cable connection at the foot pedal you will notice that is not a fixed connection rather a spring loaded one, which allow a small pedal travel past the full power setting.
The adjustment screw under the sensor is not that easy to reach, a very short open 13mm is doing the trick, while the other one is a larger plastic nut to be turned with the fingers.
Karl
 (IMG_5769.JPG)
Attachments
----------------
 IMG_5769.JPG (80KB - 0 downloads)
|
|
| |
|
fernweh
Date registered: Apr 2006
Location: Calabasas, CA - Centenario, BCS - Luebeck, Germany
Vehicle(s): Few Mercedes-Benz, a Toyota Amphibious and a Vespa
| RE: Pedal Value Sensor Error MBUSA G500
I didn't think this picture turned out to be good......
The throttle cable just below the sensor
Karl
 (IMG_5772.JPG)
Attachments
----------------
IMG_5772.JPG (102KB - 3 downloads)
|
|
| |
