Rear Parking Sensors u/s

[rdmstewa]

Hi Folks
I've just acquired a 2013 212 E350 estate which is generally in very good condition. But when I select reverse the rear sensor display beeps and shows double red, like the car is hard up against something. But it isn't. The front ones are OK. Obviously I'm going to get this looked at, but has anyone any ideas as to what might be causing this?
Many thanks
Malcolm

 

[Rotorhead500]

Possibly a duff sensor.

With ignition on, put car in reverse, then put your ear against each sensor in turn. If the sensor is working, it'll emit a soft hum/whine. If it's silent, it's duff.

Edit: If they're all apparently working, or none are (more typically), it could be the control module.

 

[rdmstewa]

Thanks folks - how easy is it to replace the control module?

 

[mioba]

Not sure there is a seperate module for the front and rear, but could be wrong. Dont guess and throw money away. A good indy will put it on diags for free (only takes 10 mins) and telk you what is what. Go from there.

 

[rdmstewa]

Thanks mioba - as there's one or two other things that need looking at I've got the car booked into my local indy next week and they can give me a list!

 

[rdmstewa]

Possibly a duff sensor.

With ignition on, put car in reverse, then put your ear against each sensor in turn. If the sensor is working, it'll emit a soft hum/whine. If it's silent, it's duff.

Edit: If they're all apparently working, or none are (more typically), it could be the control module.

 

[rdmstewa]

Thanks Rotorhead - I'd do that but if I got down there to listen to the sensors I'd not get back up. I hate the ageing process! It's going to my indy next week... I'll keep you posted.

 

[rdmstewa]

Thanks Rotorhead - I'd do that but if I got down there to listen to the sensors I'd not get back up. I hate the ageing process! It's going to my indy next week... I'll keep you posted.

Thanks All - it was a dud sensor, now replaced.

 

[ajlsl600]

Possibly a duff sensor.

With ignition on, put car in reverse, then put your ear against each sensor in turn. If the sensor is working, it'll emit a soft hum/whine. If it's silent, it's duff.

Edit: If they're all apparently working, or none are (more typically), it could be the control module.

Possibly? Given benz shxxe sensors almost certainly

 

[00slk]

I've got duff sensors on the Money Pit, oh well, there's a surprise