Parktronics 2012 ML350

[Don Boser]

Dear Forum,

I am a new member and my wife recently had a fender bender and I hadn’t checked the car thoroughly after the repairs were made . I noticed that as soon as she went to leave the garage, the red lights flashed on the Parktronics. I cleaned the sensors but no change. I used a Scanner and noted that all the sensors were reporting low voltage. I then removed sensor and cleaned the connectors with electro clean. I noticed one sensor had two wires that were spliced and the third one was simply rapped with electrical tape. My question is could this wire harness repair cause a fault on both the front and rear Parktronics sensors? I also noted that if I remove one sensor completely the whole system goes black with no lights lit.

Any feedback would be appreciated!

 

[John Laidlaw]

Welcome

 

[Uncle Benz]

Any damage to the wiring loom is going to cause issues. Its a relatively small section of loom and shouldn’t be too expensive or difficult to replace. You might still have a bad sensor, but if the loom is obviously bad I’d replace that first

 

[Chrishazle]

If you're close to Lightwater Surrey a trip to comand.co.uk would identify and fix the fault.

 

[Don Boser]

Any damage to the wiring loom is going to cause issues. Its a relatively small section of loom and shouldn’t be too expensive or difficult to replace. You might still have a bad sensor, but if the loom is obviously bad I’d replace that first

Thank you so much for the reply. Two of the wires ( orange and brown) were soldered and heat shrink sleeves installed. The third wire, yellow, had the strands of wires exposed but were simply wrapped in black electrical tape. Is there any voltage measurements I could make on the pins to confirm the correct readings ? Can one sensor disable the whole system as even the rear four sensors are showing two red lights when reverse is engaged.

 

[Uncle Benz]

Yes, one bad sensor can take the whole system down. The only judgement you can make without diagnostic equipment is if the fronts work correctly when moving forward at very slow speed, but the system goes to all reds in reverse the faulty one(s) lie at the rear. Without a code reader you are down to replacing one at a time in a trial and error manner.

 

[Don Boser]

Thank you so much for the reply. Two of the wires ( orange and brown) were soldered and heat shrink sleeves installed. The third wire, yellow, had the strands of wires exposed but were simply wrapped in black electrical tape. Is there any voltage measurements I could make on the pins to confirm the correct readings ? Can one sensor disable the whole system as even the rear four sensors are showing two red lights when reverse is engaged.

I have read that a single sensor will manifest itself a a single yellow bar illuminated. Is there a complete description anywhere of exactly hue the system operates? What happens if two sensors fail? Finally what causes the complete system shutdown?

 

[Don Boser]

Yes, one bad sensor can take the whole system down. The only judgement you can make without diagnostic equipment is if the fronts work correctly when moving forward at very slow speed, but the system goes to all reds in reverse the faulty one(s) lie at the rear. Without a code reader you are down to replacing one at a time in a trial and error manner.

I have a code reader and have read the error messages. Please see attached photo. I have reset the codes then engaged the system and faults are duplicated.

 

[Uncle Benz]

I have seen a single sensor cause the whole system to go down. The fault condition is four red bars on the front or four red bars on front and rear displays. That is as opposed to four red bars and all the amber bars showing at the same time, which is you are really, really close to something. You occasionally see a glitchy sensor where it works some of the time, but occasionally flashes to full Amber and two red when there is nothing there. In this condition the glitchy sensor will show on only one side of the display, and that helps to narrow down which side of the car it is on.

 

[Uncle Benz]

I see you are using a Snap On tool. I have one of these. Mostly I use it to stop the loo door blowing in the wind. They are notoriously poor with identifying parktronic faults. They used to have the left and right muddled up. Front was always correct but on the back, left was right and vice versa. On the later release of the software they dropped left and right and just changed to numbering the sensors. You are still on your own which side to start counting from. Lol!

I don't believe you have six sensors down. I'm still looking at the loom. Fuses might be worth a look, but I think the whole thing would be down and your scanner wouldn't communicate

 

[Don Boser]

I checked the fuse in the passenger cabin #15 and it is good. The scanner clears the codes but as soon as I hit drive or reverse they come back. Thanks so much for the info. It is greatly appreciated

 

[Don Boser]

One last comment, I swapped the two inner sensors and did not see a change in the scanner codes

 

[JBell]

You really need to have it properly diagnosed to find out which sensor is faulty. This will give you a number and you can then replace that one, they are numbered from the front passenger side (by the front wheel) in a clockwise direction (if you are looking down on the car)

 

[Don Boser]

As a quick follow up on Parktronics fault, while using the SNAP On I thought I had cleared the sensor faults as they appeared to be immediately present. However, the faults WILL Not clear unless you have the vehicle in either Drive OR Reverse. Once I did this, the faults immediately cleared and the system returned to full operation.

Be sure you have the vehicle in either Drive or Reverse when reading or clearing Parktronics codes. A big thank you to the Forum for input on this problem.

 

[Mr Greedy]

Just found this thread whilst trying to diagnose a possible parktronic fault on an E350 W212.
Had the rear bumper off and resprayed and I was worried that if they had painted over the sensors, they might not work. They had moved the car whilst the bumper was off, and this had logged low voltage errors (because it wasn't connected).
Cleared the codes as in Drive suggested by Don Boser above, and hey presto, all working.
I was using iCarsoft CR Pro, and once cleared, all the readouts on the scanner for individual sensor distance from object were reporting live data again (up to a maximum range of 255cm). Very happy with this.