2012 BTC weird 'protect' mode
Thread Starter
Member
Joined: Nov 2011
Posts: 146
Likes: 2
From: Hollywood Fla
Defender 90/360 Modena/2012 MLBTC on order
2012 BTC weird 'protect' mode
My BTC is doing a strange thing. It's going into a mode where the engine revs are restricted to below 2000rpm...it still accelerates slowly and acts like the transmission is a CVT.
This happens often after the car is started in the morning..usually as I go to the gym...but operates fine on my return trip home. Sometimes I get a check engine light...which goes out after a subsequent drive or two. Sometimes I get no check engine light.
I suspect it is the transmission control module...when it's in 'protect' it will not respond to the paddles.
I have an appointment tomorrow with the service manager at the dealership who believes there may be a code even tho the check engine light out.
Hoping anyone who has experienced this might shed some light on this issue.
This happens often after the car is started in the morning..usually as I go to the gym...but operates fine on my return trip home. Sometimes I get a check engine light...which goes out after a subsequent drive or two. Sometimes I get no check engine light.
I suspect it is the transmission control module...when it's in 'protect' it will not respond to the paddles.
I have an appointment tomorrow with the service manager at the dealership who believes there may be a code even tho the check engine light out.
Hoping anyone who has experienced this might shed some light on this issue.
Junior Member
Joined: Dec 2014
Posts: 60
Likes: 2
From: Calgary AB
2012 ML350 BT, 1998 BMW 540i/6
I'm still learning about my vehicle, so this is all educated guesswork. However, the check engine light should only come on for an emissions related problem. It will turn off after a few drive cycles if the problem clears, or was just momentary.
A serious emissions related problem can cause the engine to go into limp home mode - this is normally done to protect something. For example some of the more serious cat converter problems on my old BMW caused the engine to go into limp home mode.
If the check engine light goes out, the code that caused it is still retained in memory for a few more drive cycles. Alternatively there could also be an independent transmission problem code that would not affect emissions, so would not trigger the CEL. I think your service manager is correct to want to read the codes and see what it going on.
... but I'm sure you already know all this because you would have been to the dealer and back by now. What was the result?
A serious emissions related problem can cause the engine to go into limp home mode - this is normally done to protect something. For example some of the more serious cat converter problems on my old BMW caused the engine to go into limp home mode.
If the check engine light goes out, the code that caused it is still retained in memory for a few more drive cycles. Alternatively there could also be an independent transmission problem code that would not affect emissions, so would not trigger the CEL. I think your service manager is correct to want to read the codes and see what it going on.
... but I'm sure you already know all this because you would have been to the dealer and back by now. What was the result?
Thread Starter
Member
Joined: Nov 2011
Posts: 146
Likes: 2
From: Hollywood Fla
Defender 90/360 Modena/2012 MLBTC on order
3 days at the dealership and not a word from either my service writer or service manager.
I don't yet know if they found any codes...despite this limp home mode occurring over a dozen times
I don't yet know if they found any codes...despite this limp home mode occurring over a dozen times
Junior Member
Joined: Feb 2016
Posts: 55
Likes: 2
2013 ML350 BlueTec
I had a similar problem with my 2013 ML350 Bluetec. Driving home on day one from dealership. Engine light came on, then limp mode. RPM didnt go over 2000, and 50mph was my top speed.
Anyway, after a few days at the dealer, they said it had something to do with the oil filter not properly seated. Honestly, I dont believe it. I think its bs, but whatever it was, they fixed it. I interested to see what the real problem was.
Anyway, after a few days at the dealer, they said it had something to do with the oil filter not properly seated. Honestly, I dont believe it. I think its bs, but whatever it was, they fixed it. I interested to see what the real problem was.
Thread Starter
Member
Joined: Nov 2011
Posts: 146
Likes: 2
From: Hollywood Fla
Defender 90/360 Modena/2012 MLBTC on order
Spoke to service writer Saturday..said it was a vacuum leak. I do not really believe him.
This problem only began after the dealer dealt with a previous CEL.
This problem only began after the dealer dealt with a previous CEL.
Junior Member
Joined: Feb 2016
Posts: 55
Likes: 2
2013 ML350 BlueTec
Nothing new, but there seams to be a lot if trial and error when it comes to fixing these complicated cars. CEL,limp mode errors are very general warning lamps. Many problems from mechanical to software are attributed to trigger an error. I think many times, its a combination of multiple problems and mechanics just fix one thing. Much like the blue screen of death in the old Windows operating system, its never just one software or virus thats the cause.
My Acura MDX had a simple squeek in the suspension. They must of changed 5 components over 3 months before it disappeared.
Also, a service adviser cannot come back and tell you that they dont know what the problem is and lets "try" something. These guys are paid $150/hr....they MUST know what they are doing....or at least appear to.
My Acura MDX had a simple squeek in the suspension. They must of changed 5 components over 3 months before it disappeared.
Also, a service adviser cannot come back and tell you that they dont know what the problem is and lets "try" something. These guys are paid $150/hr....they MUST know what they are doing....or at least appear to.
