Limp mode / safe mode ??

[DanInDenver]

Left my car at the airport temperatures have been in the single digits all week. Left lot lost all power check engine light on, VSC track light on, VSC off light on, no power. Idle is at 1600.
Pushing gas pedal has no affect on rpm's until it's almost to the floor. Pulled over waiting on tow.

Ideas?

 

[Trunk Monkey]

Pull the CEL code, could be dozens of things.

 

[DanInDenver]

Still waiting for tow. Turned on and off several times. This last time revs went down , and gas pedal action is reacting normally, ok to drive with check engine light on?

 

[Glacierskier]

How did it turn out? My 2000 is sitting under 16" of snow 90 miles west of you.

 

[DanInDenver]

Drive it home with the warning lights on. Code tester read a P1120. Which I am told is the TPMS . I am hoping it was due to the cold and not letting it warm up. Will look into replacing the TPMS

 

[Trunk Monkey]

Yes, it's fine to drive. Sounds like something with your accelerator or throttle position sensors. Mine went when it first got real cold. Hopefully it's the TPS ($$) vs. the APPS ($$$)

 

[EdsCruisin]

Hopefully it's the TPS ($$) vs. the APPS ($$$)

Got that right! Replaced my APPS two times. At best it is unpredictable to drive, as it could go back into limp mode at any time.

Funny how you entitled this thread as "Limp Mode/Safe Mode" In my opinion there should be no limp mode, because it is super dangerous. Drive down a two-lane, hilly, curvy road in limp mode and I will tell you that you wish you had a diaper on. The only place where limp mode is "safe" is in a parking lot or on a wide shoulder.

 

[AimCOtaco]

Glad you made it home without a tow. I would let it soak awhile if you can and see what happens. A lot can go wrong in the throttle body when it's cold and the codes won't always be consistent. Ours would go limp every few months and the code was not always the same. I ultimately decided it was more likely mechanical and internal to the TB than just the APPS or TPS and ended up with an all new throttle body to ensure a fix and avoid limp mode in dangerous places.

There is a motor/clutch that actually drives the throttle plate through a greased gear train so in the cold I suspect that could be sticking...

I know all my steering pumps have been crying all week in this bitter bitter cold we've been enjoying.

 

[2000UZJ]

Got that right! Replaced my APPS two times. At best it is unpredictable to drive, as it could go back into limp mode at any time.

Funny how you entitled this thread as "Limp Mode/Safe Mode" In my opinion there should be no limp mode, because it is super dangerous. Drive down a two-lane, hilly, curvy road in limp mode and I will tell you that you wish you had a diaper on. The only place where limp mode is "safe" is in a parking lot or on a wide shoulder.

Very true statement. I have never had an APPS/TPS issue with the 100. We did have an issue with a 2006 E-Class. I was driving on a twisty road with hills. Apparently when the E-Class senses a throttle error it applies the brakes (I guess to avoid a full throttle situation?). It slows down similar to coming to a normal stop. I was stuck at the end of a blind corner at the bottom of a hill in the middle of the road with my foot through the floor and nothing happening. I ended up putting it in neutral and rolling into the ditch, almost rear ended by a semi.

If there is a chance you may loose throttle input, don't drive it. People don't expect a dead stopped vehicle in the middle of a blind corner.

 

[OregonLC]

Got that right! Replaced my APPS two times. At best it is unpredictable to drive, as it could go back into limp mode at any time.

Funny how you entitled this thread as "Limp Mode/Safe Mode" In my opinion there should be no limp mode, because it is super dangerous. Drive down a two-lane, hilly, curvy road in limp mode and I will tell you that you wish you had a diaper on. The only place where limp mode is "safe" is in a parking lot or on a wide shoulder.

Very true statement. I have never had an APPS/TPS issue with the 100. We did have an issue with a 2006 E-Class. I was driving on a twisty road with hills. Apparently when the E-Class senses a throttle error it applies the brakes (I guess to avoid a full throttle situation?). It slows down similar to coming to a normal stop. I was stuck at the end of a blind corner at the bottom of a hill in the middle of the road with my foot through the floor and nothing happening. I ended up putting it in neutral and rolling into the ditch, almost rear ended by a semi.

If there is a chance you may loose throttle input, don't drive it. People don't expect a dead stopped vehicle in the middle of a blind corner.

On the 2000 you have a cable back up that most people aren't aware of. Press the pedal down to the point where you get resistance and then press harder. The APPS on the earlier years is located at the TB. There is a conventional mechanical cable that runs from the pedal to the APPS. The cable rotates the APPS cam which normally directs the TB servo, however during failure the cam hits a stop at about 2/3 travel where it reverts to manual control. It's difficult to modulate but keeps you from becoming stranded. You can completely unplug the TPS and APPS and still drive the 2000 (and probably earlier years too). I've driven around town this way and up some steep hills and you have good power, although I don't think it gets it 100% open. Slack does need to be removed from the cable for this to work properly which should be part of normal maintenance anyway. If you try it, know that you'll have a code thrown that will require a code reader to clear.

You can also try it with the engine off. Pull off the intake and turn the cam on the PS side. Nothing, nothing, nothing and then at about 2/3 travel you feel the stop and see the butterfly open.

 

[drmwvr]

This just happened to my '99 with 195k. Going to mechanic in morning. Any thoughts on range of costs for best case (sensor) to worst case (throttle body)?

Thanks!

 

[Trunk Monkey]

TPS is $80, APPS is like $220, throttle body is a lot more. Then labor on top of that.

 

[drmwvr]

TPS is $80, APPS is like $220, throttle body is a lot more. Then labor on top of that.

Thanks!





Walk of shame ;(

Oh well, first time on a flatbed in 15 years...not too bad!

 

[drmwvr]

TPS is $80, APPS is like $220, throttle body is a lot more. Then labor on top of that.

Just heard from my mechanic. It was the PPS so not too bad cost-wise. Thanks for the references!

 

[Old#7]

Anyone have the same symptoms with no CEL coming on? This is what I am up against right now. It doesn't happen all the time just intermittently

 

[Trunk Monkey]

Mine did it a couple times before it triggered the CEL. Certain set of parameters has to be met to trip that.

 

[stinkyfj60]

i'm replying to this thread so that I can reference it.

I just left to run an errand, I let it warm up slightly, but then went down a pretty steep Seattle hill in traffic. At first I thought something was up with the brakes, but I noticed it was idling funny. then the check engine light and all the VSC lights came on...

it got me home of course, but it's running a little rough and smells awful.

 

[stinkyfj60]

I checked my... missing on #3 and #6; it's probably coil packs.

I'll clean the MAF, check wires and hoses, swap the coil packs to #2 and #6, clear the code and drive it and see if it does it again (but on the swapped cylinders)

 

[merbesfield]

My daughter’s 02 has done this twice. No CEL. Suggestions? She’s to scared to drive it now. Thanks Mark