Moving from recommended repair shop section

 

There are impact sesors behind bumber, which should be connected and working too, for active bonnet. Bonnet actuators are under the hinges of the bonnet, could be broken wire there too (mine gives error too always when raining, code is short circuit of the bonnet actuator. Not removed actuator yet for wire check.)

 

Hey I had the same problem all you have to do is call your local Mercedes Benz dealer and tell them that you need 2 hood latch sensors don’t let them tell you they can install it cause it’s easy took me 2 min to change mines it’s plug and play literally it’s about 23$ bucks for one I say get 2 you should be okay after you install new ones

 

I had same problem with sometimes if I didn't hardly slam the bonnet when closing it.

But I had experience with my W212 E300 Avantgarde that happen just recently and my mechanic said it is rare to happen, my bonnet just pop-up at both of its bracket hinges and struts when I accidently hit a road potholes when turning so its not really fast (about 30 mph speed), they just come up about 8cm high and I have to stop in the road shoulder, I call my mechanic and repairing them without any part replaced.

I wonder if it safe to drive with this condition where there i might hit the potholes again, is it a Mercedes Benz feature not to fully fixed the bonnet bracket in W212 to its body frame? Any of you guys have same experience like this?

 

owners manual explains how to push bonnet back

 

I’m gonna check the owners manual again, thanks for your information

 

I have Active bonnet malfunction message. Further scanning shows two errors A700 and A702 (sensors internal fault). I bought and replaced those two sensors with second hand ones but the errors and message still there. I do not want to buy a brand new sensors as I am not sure it is faulty sensors. All sensors shows internal resistance of 440-460 kohm. any ideas? Thanks

 

Which sensor those codes are pointing? Bonnet 'jump' actuators, bonnet close sensors, acceleration sensors or impact sensors? All needed for active feature. Which sensor you changed?

 

A700 There is an internal fault in the left sensor for function "Active engine hood!"
A702 There is an internal fault in the right sensor for function "Active engine hood!"
Sensors are A172905600 Location left and right inside the bumper
Thanks

 

So you are not getting actual sensor definition... B48/1 and B48/2 are acceleration sensors, B151/1 /2 and /3 pedestrian protection sensors, couldnt find bonnet open/close sensor definition... then bonnect actuators have their own code, you need to find out WHICH of them is source of your fault code.

 

B151/1 and /3

 

they are pneumatic sensors, I don't know how self test is done by ecu, but did you check pneumatic line has no leak? It is rare that two sensors fail at same time. How did fault started, what there any repair prior that?

 

It is not pneumatic and there is no pneumatic line. There are 3 pedestrian protection sensors inside the bumper. The central (yellow is OK). However left and right (green) are not OK. I bought a car already with this issue. I assumed there was a minor accident from previous owner (there was some minor damage to the bumper which I have already fixed) which triggered this issue.

 

If you are talking about B151, they are pnaumatic. There is a hose between them and if car bumps something which penetrates bumper, hose will be pressed/squeezed, pressure rise detected and triggers actuation.

Edit: evidently tehere are two different systems, pre / after march 2013

Redirect Notice

 

I am talking about the pedestrian protection sensors whatever code they have. There are 3 pedestrian protection sensors. And they are not connected to pneumatics. central yellow one is Ok. Green left and right are the same and SRS shows errors for both left and right pedestrian protection sensors.

 

Yes, If you open WIS document I linked, its there. Pre 2013 its not pneumatic. You don't say which MY car you have, but evidently older than 2013...

What is really weird you got TWO sensor failure at same time, which points to module problem.

 

I just installed brand new sensors but errors are still there.

 

Did you find out of the errors? I have same issue. Both L and R sensors showing errors. Middle one is ok. Tried to switch them with each other -same errors. Tried to connect a used ones - same errors. Are about to buy new ones but don't feel it'll help. Did you get any luck repairing these?