MKW

Trying to be topical, suppose a GL developed a sudden hiccup in the electronic control module and revved the motor to redline while at speed... yes, I know that MBZ have a brake pedal override circuit that is supposed to shut down the motor in that situation , where Toyota's don't.
But just curious, can the GL be put in " Neutral " while at speed if you just push the stalk button inwards ( same button motion as putting vehicle in " Park " after coming to a complete stop ) ?

ima55r2

You should try it on your GL.

I've pushed in the stalk by mistake a couple of times when forgetting which car I'm in and nothing happens except for a dash message about engaging park while stopped.

If in any car that ran wild, I would turn it to the off position that would not lock the steering wheel.

alx

yes you can. the truck will coast... if you want later to reengage gear---- rev up to say 2000 rpms and push the stalk to "d"... if you get it right the engage will be smooth.

on a gl you can also simply hit the start/stop button and engine will stop.

speaking of runaway engines - a diesel engine can runaway uncontrollably- especially a turbodiesel - all it takes is a worn (or torn) turbo oil seal that allows engine oil to get into the intake ... where it will be drawn into the cylinders and burned resulting in more rpms, resulting in more turbo boost resulting in more oil in the intake... this continues until engine runs dry of oil and seizes. remember- the diesel engine's fuel is oil to begin with and rpms are controlled not with a throttle body but strictly with the amount of oil injected into the cylinders...

on the topic of general runaway vehicles- _any_ non-commercial (big) vehicle can be stopped by firmly applying the brakes and holding them. brake distance might be a little longer, but you will stop.

alex

MKW

So if I push in the stalk it goes to Neutral ? ima55r2's post says it doesn't . My wife asked and I don't know the answer.

Thanks in advance .

MB211

Nuetral is a half click up or down.....

robalo220

No. Pushing in on the park button does nothing while driving. Push it "up" part way to get neutral. If you push it up till it clicks as if going into reverse, it still goes into neutral. All electronic and wont blow the tranny while driving and trying to shift into reverse. Manual states not to do this as it will damage the tranny. I had to test this tho. I usually coast down long hills. You don't have to rev up to engage, just click into drive, wait about 3 seconds to allow engagement, then hit the accelerator and it will be smooth as silk. I do not have keyless go and do not want to turn the ignition off and lock the wheel and shoot off the edge of the road in a curve with no brakes with the engine off. Keyless may let you continue to steer. I dunno. Wouldn't want to try that one. When I was a kid my older brother coasted down a long hill and cut off the engine to "save gas" and locked the wheel and flew off the road into some woods. No serious injury but the car was lost. Food for thought. The new electronics may not let the wheel lock when moving but again I am not trying it out.
Cheers!

ima55r2

You might have it backwards.

The keyed ignition has 3 positions...off, on, and ignition. While driving and turning the key to the on position will turn the engine off and not lock the steering wheel. The power assist is also turned off so steering will take some effort. I just tried it at a couple of mph so I know it works. Turning the key to off, will lock the steering.

Since I don't have keyless go, I am just guessing, but it would seem to only be off or ignition and thus lock the steering.

Again, pushing the stalk in does nothing...and you can accelerate while pushing in the stalk.

Neutral is a light lift or push down without going into reverse or drive.

The OP referred to an electronic module failure and at WOT. If the car can go into neutral...great, but if not the best bet is trying to turn of the engine. Applying the brakes at speed is going to be a shakey proposition. When the car does come to a stop, what are you going to do?...have everyone jump out and then watch the car peel out on its own?

StevethePilot

So you're saying this is when the car has some sort of failure of the override of the braking system's ability to overcome the throttle (basically disengage it, if I'm not mistaken)? I think applying brakes at speed is something someone does every single time they slow down for a freeway exit. Trying it without the power assist is probably the scary proposition, as is trying to be sure you've only cliked the key once and not locked up the steering, and then trying to overcome unassisted steering. And are you saying that once you've come to a stop, you wouldn't then put the car in park or at least turn off the engine? Why?

ima55r2

Maybe you didn’t read the first post in this thread correctly. The car is stuck at wide open throttle and not coasting to a freeway exit.

Not having the power steering might not be a big deal at speed and slowing because someone would have to be on a relatively straight freeway or else they would have crashed sooner on some curvey mountain road.

In a panic and if someone doesn’t know all the options, it will only lead to disaster.

Here is a supposedly skilled CHP trooper trying to control his car with a stuck pedal and not some catastrophic electronic failure.

http://www.sandiego6.com/mostpopular...uxTtxrK4Q.cspx

QuadBenz

To the poster who said you can press the start/stop button and the vehicle will turn off, that is simply not true. You cannot turn off the vehicle using the Keyless Go button while the car is moving.

alx

mine shuts down anytime you press the star/stop button. i have keyless go. you lose powersteering, but steering column does not lock up. there is also a few brake stomps reserve left.

also every non-commercial vehicle is capable of stopping by simply applying the brakes. and once you come to a stop or close to- butt it up against a wall, guardrail, etc.

100% of the runaway vehicle crashes were due to driver's panic.

and yes, the cop that wiped out his family in a runaway lexus did panic. the "trained professional" had enough time to call 911, but not downshift, slide into neutral, click the engine off or just stomp on the brakes and hold on.

43221B

There is a good article on Car an Drivers website, "How to Deal With Unintended Acceleration". The bottom line is that even with a high performance high hp sports car you should be able to stop your car rather effectively with the brakes. Although they don't say it, there is something that doesn't add up in the case of the highway patrol officer.

MKW

OP here .

OK , finally got to drive the GL today .
When car is rolling, you can see a small arrowhead in the dash display pointing from " D" to " N". If you push the stalk upwards ( slightly or even all the way ) , it does go into Neutral . Simply push downwards and it goes back into Drive. The arrowhead alerts you to what the tranny will allow you to do at that moment.

However, if vehicle is rolling BELOW about 10 mph but not at a complete stop , I notice that there is now also an arrowhead between " N " and " R" , so if you push it all the way up, it possibly COULD go from Drive into Reverse at that speed !! I didn't dare try it to find out.

Bottom line : If you ever experience that " Camry " feeling, 1) use the brakes as you flip the stalk upwards 2) turn off ignition if needed. Might want to share this info ( and practice the " D" to " N" maneuver) with other drivers of this vehicle , as these electronic column stalks are not intuitive like the ol' mechanical " PRNDL " floor shifters .

Benzo 003

I have "toyed" with this idea very recently. All tests were performed in a ML350 loaner:

cruising at 65 with cruise control on - bumped the stick into N and the tach jumped up maybe 500 RPM before kicking off the Cruise and just coasted.
cruising at 65 and trying to put it in R or P cannot happen. An error message appears letting you know that function is not possible while moving.

In the case of WOT at any speed, my opinion is to never shut the engine off and sacrifice P/S and P/B.....bump it to N, steer it to safety, then shut down. Let the motor blow need be. An engine/trans can be replaced, my life and family cannot.

In the case of the CHP officer, I believe he was in a Lexus rental, not a police cruiser. Sad, but I think he dropped the ball.

StevethePilot

Well, maybe you're not reading the title of this thread correctly; this thread is for folks who drive Mercedes Benz cars. Among those who drive German cars, there is a specific method for overcoming a stuck accelerator, and that is to mash on the brakes while coming to a stop in the position of your choice. Should you choose to put the car in neutral first, you can do so. But as you are hurtling towards that curve in the road with the 1000 foot dropoff (see I-17 northbound coming in to Camp Verde), do you want to shut off the assistance to the brakes and steering by turning off the engine, thus saving lots of fuel while the emergency crews try to rescue what's left of you from your car, or do you want to keep the steering and brakes while safely stopping on the shoulder (in Europe, the 'Verge') and shutting your car off?

For reference regarding what's accepted as the proper method for overcoming a stuck throttle (and with reference to Start/Stop button equipped cars), please see this article and video.

STP

dgiturbo

The transition from D to N to R can be done under about 8 MPH so that a driver can rock a stuck vehicle back and forth to free it from mud etc. The procedure is described in the owners manual as a SUV feature. At higher speeds, the arrow on the dash will indicate what gear is possible, and the computer will prevent anything else.

As far as the stuck gas pedal or diesel malfuntion, fortunately Mercedes uses brakes big and powerfull enough to stop this thing at full throttle, top speed, even downhill. That's why I paid the money for a Mercedes and not another brand.

As Steve said, MASH ON THE BRAKE PEDAL and the vehicle will stop. Onced stopped, regain your composure and then worry about shutting down the motor.

MKW

More than mashing on the brakes to physically stop the car, most if not all German makes have a signal to shut the motor down via the ECU if you are panic barking and the engine RPMs are " out of control". Toyota does not have that electronic overide feature and separately had recently announced that all 2011 models will come with it .

alx

true for gassers. but you cannot stop a runaway diesel via engine mgmt methods. cutting fuel does nothing as the turbo blowby feeds engine with engine oil. cutting electricity does nothing as diesel does not rely on electricity to ignite mixture nor it relies on fuel pump (in this case) to supply fuel. the only solution is a fire extinguisher discharge in the intake or a rag... but for that you need to be stopped in the first place. and it will be tricky with the gl320 as the v6 has two air intakes.. so you need two rags... or be very handy/quick with a single fire extinguisher..

AMGfan

OT: I heard the 911 call a couple of days ago from that incident and it was truly horrific. All the time I was listening to it, I kept yelling in my head to "throw it in neutral." BTW...did they ever find out what caused the stuck accelerator?

dgiturbo

If I remember from my past time, this would be true for the older diesel benz and domestic pickups. (Usually the Powerstroke series) The CDI and Bluetec's have a electrically controlled throttle, and it is very effective in reducing engine power. (Same theory as the rag you mentioned above.) That's also how they get the ESP stuff to reduce the power in ice conditions so quickly.
As for the oil blow by, these newer turbo oil seal you mention will fail safe to the exhaust cartridge, so a bad turbo seal will give exhaust smoke not feed through to the compressor housing. And even if there is some chance of contamination, (crankcase breather) that same oil has to go through several large hoses and fill up a large intercooler before it makes its way to the induction side. By then, the ECU will 'see" the unmetered stuff and go to limp home/shutdown. Also this is another reason we use the Mobil1 229.51 spec oil. It has a really high flash point. (456F I seem to remember.)
Look around the engine, you will see that there is no "strangler" lever as the older vehicles had. Modern engineering has made those issues obsolete.

Oh and one other good thing for us diesel people, our braking system is powered by an engine driven vacuum pump, so as long as our engine is running, we always have vacuum and wont lose power brakes.

QuadBenz

Strange. All the KG equipped vehicles I've tried this on did not allow the engine to shut down.

StevethePilot

Just quickly, I want to openly apologize to ima55r2 for being snitty in my reply. It's no excuse but I was just in a bad mood and should've avoided sending a message at all that day. Sorry about that.

alx

http://www.youtube.com/v/M-pxsViKF88

dgiturbo

Alx, neat video above, but what can you say what caused it? How was this vehicle serviced prior? And if it is in support of your "oil contamination theory", how did the other guy that drove up switch it off without a "rag" or "fire extinguisher"? Looks like he knew how to press the off button on the KG as the owner had no clue what to do.
The video look to me like an ecu/injector malfunction (or if BMW uses one, an e-throttle issue) and not a oil contamination issue. Note the exhaust smoke was brownish diesel residue, not blue oil smoke.
Remember I said that the oil related engine runaway issue is a non issue, but automakers cant be held for what things owners do or don't do outside of the engineered scope. For example, the diesel fuel systems are designed to eliminate engine fires, but if you put gasoline in the fuel tank, the engine will catch fire.

In any event, the vehicle appeared to have been safely stopped and under control with the hazards flashing, so the runaway braking thing does not seem to be an issue here as opposed to other car brands that cant brake to a stop if the throttle is opened.

robalo220

Dgiturbo, how do you know the other guy shut it off? I think it was just timing that the engine probably began to overheat and shut down (fail) on its own. Turning the key on or off will do nothing in a "runaway" engine being fed fuel in this case probably through the leaking turbo and sucking dirty motor oil into the cylinders. The video tells us no details. Yes, dirty diesel motor oil can and does burn dark like in the video. The cause? Much of the oil is unburned and comes out greyish black. Usually see totally black exhaust during acceleration caused by unburned fuel, dirty injectors, etc. I'm guessing the guy put the vehicle in neutral and stopped before the engine died. They don't like to run long with no load wide open.
Just my two cents worth.