Limited Throttle
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From: Austin, Texas
Limited Throttle
Here is what happened, I am coming out of a parking lot onto a highway and stand on it fairly hard and after I get out of it I have little to no throttle response. If this was a 18 wheeler I would say it went into "limp" mode, I could manually shift (auto) and get a little better response but not a lot and NO check engine lights. I know big truck's with drive by wire sometimes do that (usually sets a check engine light but not always) and you can cycle the ignition (reboot the computer) and everything is fine so I did just that and all was right with the world again. I drove almost 100 miles after, stomped on it several times and no recurrence of the complaint. Have any of you heard of this or had it happen to you? If so did it happen again? I thought I remembered reading about something like this but couldn't find it.
Thanks,
Paul
Thanks,
Paul
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Joined: Jan 2008
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From: Virginia
Re: Limited Throttle
Strange that it just magically happened but you might want to do the petal reset and see what happens. I know when I got mine there was a good half second delay between pushing my foot down and it actually opening up. I know the system is suppose to adapt to your driving habits so if you don't get into it a lot the response is mellowed out.
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From: Aurora , ILL
Re: Limited Throttle
I to have read about this "limp mode"
My question is why does it occur ?
Fortunately mine has never done this and I have driven it 17000 miles now.
My question is why does it occur ?
Fortunately mine has never done this and I have driven it 17000 miles now.
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From: Austin, Texas
Re: Limited Throttle
Although it did not set a code (at least I do not think so, no lights) I believe it did go into "LIMP Home Mode" this is from the service manual:
ZH
ELECTRONIC CONTROL MODULES - SERVICE INFORMATION 8E - 59
LIMP-HOME MODE
In order to ensure safe driving and to prevent further damage to the automatic transmission, the Transmission Control
Module switches to limp-home mode in the event of a critical failure. A diagnostic trouble code assigned to the
failure is stored in memory. All solenoid and regulating valves are thus de-energized. The result is that the gear last
engaged remains engaged, the modulating pressure and shift pressure rise to the maximum levels, and the torque
converter lockup clutch is disarmed. In order to preserve the operability of the vehicle to some extent, the automatic
transmission internal hydraulic control can be used to engage second gear or reverse by: stopping the vehicle,
switching off the engine, moving the shift selector lever to Park, waiting at least ten seconds, starting the engine,
and moving the shift selector lever to drive to access second gear, or moving the shift selector lever to Reverse if
needed. The limp-home function remains active until the failure is corrected or the stored diagnostic trouble code is
erased. Sporadic failures may also be reset by switching the ignition switch from Off to On.
Module switches to limp-home mode in the event of a critical failure. A diagnostic trouble code assigned to the
failure is stored in memory. All solenoid and regulating valves are thus de-energized. The result is that the gear last
engaged remains engaged, the modulating pressure and shift pressure rise to the maximum levels, and the torque
converter lockup clutch is disarmed. In order to preserve the operability of the vehicle to some extent, the automatic
transmission internal hydraulic control can be used to engage second gear or reverse by: stopping the vehicle,
switching off the engine, moving the shift selector lever to Park, waiting at least ten seconds, starting the engine,
and moving the shift selector lever to drive to access second gear, or moving the shift selector lever to Reverse if
needed. The limp-home function remains active until the failure is corrected or the stored diagnostic trouble code is
erased. Sporadic failures may also be reset by switching the ignition switch from Off to On.
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From: Texas Hill Country
Re: Limited Throttle
Paul, if need be, I recently took my car to Auto Haus over on N. Lamar in north Austin.They specialize in European cars, particularly MB. They can scan your computer and possibly give you some answers. Charged me 45 bucks to scan and evaluate the problem when my right wheel speed sensor took a hike. 
Just my Dos Centavos
Just my Dos Centavos
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From: Austin, Texas
Re: Limited Throttle
Originally Posted by Stogey
Paul, if need be, I recently took my car to Auto Haus over on N. Lamar in north Austin.They specialize in European cars, particularly MB. They can scan your computer and possibly give you some answers. Charged me 45 bucks to scan and evaluate the problem when my right wheel speed sensor took a hike.
Just my Dos Centavos
Just my Dos Centavos
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