W205 C63S - PMP troubleshooting

[steves2k]

Hi All,

I have recently got myself a 2019 C63S and and read SO so so many threads on tapping into fuse for the camera. but Now I have resorted to asking specialist in this forum - As I am certainly doing something wrong, I am no genius when it comes to this, but if someone could please help me out!

Below I can see there is continuous power and proven to do so, I have tapped into the Central Locking System
However, without fail - 2 hours, the camera along with the PMP completely shuts off, so I go to the TRUNK and test the power, and it still shows it has power to it, so I am at lost now.

I am using 15A fuses for both ACC and BATT (Hope that works?) - PMP Is set to 12.5V

ACC is connected to the cigarette lighter whilst the the BATT is connected a 30A Central locking system

is my battery faulty? PMP Faulty? Grounding wrong location? I am at loss and not sure what my next cource of action is thank you in advance

 

[Ralph2]

If your PMP is turning off at 2 hours sharp.. the first thing I would be checking is the time settings. The time is adjustable with the little (DIP) switches on the PMP.. are they correct? But.. looking at the switches available I do not see a 2 hour setting.. So????

 

[M8TJT]

What do you mean specifically by "the PMP completely shuts off". What indication do you have that it has shut off?

Set the voltage cut off to 12V. It's the fact that you have it set to 12.5V that is causing your problem.
Despite what folk say about fully charged batteries, their terminal voltage will drop below 12.5V in a surprisingly short time.
Please report back on this test.

PS. You should NOT fuse the PMP with 15A fuses. 3A is plenty to run the cam from the yellow wire and the red wire is only a switching wire and takes a tiny current.

 

[steves2k]

Thank you Both,
Apologies I want to correct one thing I said, sometimes its 2 hours, sometime its 3 hours- I set it to 6 hours for now to have the parking mode enabled
To Clarify about "SHutting off" - The camera and the PMP (Green Light) goes off - As if it lost power (So I went to the back of trunk and use the tester and can see power (PIcture above) . Once I power on the car engine, PMP and Camera powers back on, and the cycle continues, powering it self off at 2 hours to 3 hours. (HEck sometimes after 30 minutes sometimes)

I will set it to 12V and buy a 5A Fuse today and report back, (I also have the Tool to measure amps)

Will definitely report back thankyou

 

[steves2k]

Hi,

So I tested it with PMP 12V and a new Fuse 5A and unforunately it went off again, so I tried to plug it in another location which delivers 12V as per picture and again, it went off in around between 2-3 hours (both the camera and PMP)

I havent tested how much amp is crossing it yet, (left the tester at work...... :| )

What would be the next steps apart from seeing if the AMP is cutting below 12v? WHich i will do tomorrow

This time nothing is piggybacking off it - just the PMP BATT to a 12v and Cigeratte lighter for the ACC

 

[Ralph2]

You "could" have a defective PMP. Or.. your vehicle senses an undue (non designed) drain on the battery and shuts off that circuit.. Those are tricky to diagnose because once you open the door it re activates the circuit.

 

[steves2k]

Thanks Ralph, anything else I could try at this point? I am at loss right now what to do....

Also, Im wanting to find out something, about the grounding, How do I know (testing tool) to know that the ground cable is properly connected to a ... grounded metal object? would the grounding have anything to do with the camera switching off?

 

[Ralph2]

Try to find out if your vehicle uses technology that checks for electric “leaks”. Some upper end vehicles do evidently, they “sense” if there is a current draw above what is designed and will shut that supply off... until you open the door or the vehicle senses your proximity. It is possible you have a defective PMP.. you would not be the first.

 

[M8TJT]

The only way of progressing further is to accurately measure the battery voltage at the time, or soon after the PMP switches the camera off.
My feeling is, with 95% certainty, your car's battery voltage is falling below the 12V cut off point of the PMP.
If this is the case, then the outstanding problem is to find out why the car battery is dropping that far 'so quickly. I am not prepared to speculate on that until the voltage 'issue' has been established.

Unlikely that grounding is the problem.

 

[steves2k]

I did some research based on your response

I saw this - Perhaps a good starting point, if not, then I may resort to buying a new PMP ...

 

[M8TJT]

I just don't have the faintest idea what all that lot was about.
Post #9, sentence 1 is still valid. I assume that your car battery is fully charged by a longish run before you start your duration test?
£5 (9.6 AUD) says if you buy another PMP it will be exactly the same. But it would be great if I were to be proved wrong.

 

[steves2k]

I just don't have the faintest idea what all that lot was about.
Post #9, sentence 1 is still valid. I assume that your car battery is fully charged by a longish run before you start your duration test?
£5 (9.6 AUD) says if you buy another PMP it will be exactly the same. But it would be great if I were to be proved wrong.

Yes, I will be doing that today and report back - As odd question as it may be, as the car initiate itself when opening the trunk or doors, I will leave the trunk open for 2 hours so I can measure the Fuse when the PMP Switches off

 

[M8TJT]

Presumably you have a reasonably accurate voltmeter?

 

[steves2k]

So I got the results based on the following test

I left the boot open just to be sure that when opening it, the Volts dont go back up in anyway, ensure the key was no where near the car, and tested it with the voltmeter

When the Camera disconnected ( again at around 2 hours time everytime - Notification below for the past 3 days ) - The volts shows 12V at the battery and at the continuous (BATT) fuse.


I can definitely see it at being 12V - Is it safe to say that the Power Magic Pro could possibly the fault at this point?

 

[Ralph2]

I would suspect your battery might be the problem.. if it decays to 12 volts in a matter of a few hours.

 

[M8TJT]

I can definitely see it at being 12V - Is it safe to say that the Power Magic Pro could possibly the fault at this point?

Absolutely NOT. It is doing exactly what it is designed to do and is switching off the camera when your car battery drops to the 12V that you have set on the PMP. This is to prevent further discharge of the car battery.
See Ralph2's answer above to save me typing it.

 

[steves2k]

Thanks M8tIJ and Ralph, that concludes it then, I will have to take it to mercedes and have that battery changed (only after 1 year) - What should i tell them ? That the battery does not hold at 12 or more Volts?

 

[M8TJT]

Just get them to test it.
The technical term is that it doesn't hold its charge.

Let us know the outcome please.

 

[steves2k]

Hi M8TJT - I have come back ! this time, with a better digital tester (more expensive) and this time I tested again for a more accurate reading - This was 3 hours after the camera has shut off and that the car has been parked for 4 hours.

What do you think at this point now?

Attached is the image.

 

[M8TJT]

Ah Ha. That's better as we are talking decimal points of a Volt.
OK, the PMP should NOT be switching off at 12.45V if it is set to 12V. But it seems about right if you have it set to 12.5V though. Do you still have it set to 12V?

I found

This was 3 hours after the camera has shut off and that the car has been parked for 4 hours.

a little confusing (I am only a simple Pom you know ). You need to be measuring the voltage at the same time (or pretty close to it) as the PMP switches OFF the cam. What I understand from your sentence (probably wrong) is that the PMP switched off 1 hour after parking the car and you took the reading 3 hours after that. But I'm sure that's not what you actually mean.

So to summarise. If your voltage reading was taken at about the same time as the PMP switched off the camera AND the PMP is set to switch off at 12V, then you are correct and the PMP seems to be faulty.
But, If the voltage reading was taken more than about 10mins after, the cam was switched off, it is possible that the battery voltage recovered a bit after the load of the cam was removed (The PMP will not switch itself back on under these conditions).