LR4 2013 After heavy braking, Limp home mode started ?

[Jesster1975]

Hi all,

Just wondering if this has happened to any other LR4 or other models owners before?
My wife said she had to slam on the brakes to avoid a collision ahead and then coasted for a minute or so followed by limp home mode activating when she went to accelerate.
Luckily was not far from our house but when she got home car now won’t start at all ! just engine light comes on .
Any help / experiences would be appreciated.

james

 

[jlglr4]

Does the starter turn over? Wondering if it could be the brake switch.

 

[jlglr4]

Just to follow up - sounds like brake switch is something to check, but could be lots of things.

My thought on the brake switch was that it could have been damaged from slamming the brake pedal. The brake switch is under the lower dash, near the steering column. When the brake pedal is pushed, the switch tells the car the brakes are on. If it’s damaged, the car won’t try to start (starter will not engage - only the dash lights will come on, as if you pushed the start button without stepping on the brakes). It also won’t let the car shift, and can put the car into limp mode. One thing you can do is look at the brake lights - see if they are going on and off with the brake pedal. If not, brake switch is shot.

If that’s not it, I think you’ll need to have the codes read to give some better clue as to what might have happened.

 

[Jesster1975]

That sounds like a good place to start, I’m at work but will check it out, and get back to you.
Should the car be able to start in limp mode ?
Because it all lights up like you say but won’t even attempt to turn over .

 

[jlglr4]

Limp mode itself shouldn’t prevent the car from starting, but a bad brake switch can both prevent the car from starting and engage limp mode while running. So, I’m thinking that the brake switch was hammered while the car was running and put it into limp mode. When you shut if off, the damaged brake switch won’t let the car start again. Just a theory.

The other thing to check is to make sure the car went into park when it shut down. Since it won’t try to start, I’m assuming the gear selector doesn’t pop up when you hit the start button. But you should see the “P” lit up when you turn the ignition on indicating that it’s in park. If it’s not, that also will keep the car from starting.

I assume you don’t have a GAP tool, but even a simple, cheap OBDII code reader might help track down the problem.

 

[ktm525]

My old Volvo V70R had a module that would activate upon emergency braking / accident. I forgot the specifics but there was something that needed to be reset before the car could drive. Try googling around.

 

[jlglr4]

Inertia switch maybe? I think its supposed to shut down the fuel supply in an accident to prevent fires. I think that would have shut the car down immediately, not put it into limp mode, but I’m not sure. Maybe something to look at.

 

[ktm525]

Inertia switch maybe? I think its supposed to shut down the fuel supply in an accident to prevent fires. I think that would have shut the car down immediately, not put it into limp mode, but I’m not sure. Maybe something to look at.

Yeah that was it. It cut the fuel.