W251 R-Class EGR Issues

[ber5ien]

I have checked connector using back probe while ignition on.
I think I should expect two cables with 12V or at least one.
Is that shorting somewhere?

5 pin 533mV
4 pin 0.8mV
3 pin 5V
2 pin 261mV
1 pin 261mv

Disconnected plug
5 pin 4.1V
4 pin 8mV
3 pin 5V
2 pin 12+ V
1 pin 32mV

I have check EGR ground again positive terminal battery getting 12v so that mean the grounds is fine. I think. Socket unplug.
So why I am not seeing this when plug is in the EGR?

 

[Mersovod]

You have a 12V power drawdown when the load is connected. Search here. In the future, please indicate the VIN. Schemes may be different.
Plug is connected!

 

[ber5ien]

Should I be checking if one of the cables get disconnected causing open circuit one EGR valve is passing 12v somewhere else once connected?

 

[Mersovod]

Unwind the wiring, check the Z-clutches and the wire to the ECU.

 

[ber5ien]

Unfortunately these wiring are for 3pin my has got 5 pins.
I have check the wiring loom and apart form seeing this idiot form the factory tidy up cables it seems they are fine.
They were damaging these cables but check one which seems to have damaged and it was fine inside.

Loosing a bit of faint in this

Why would ECU be cutting of 12V from EGR.

 

[Mersovod]

5 pins and 3 wires, this is normal. The control unit turns off the output power if it detects a short circuit or no load. Inspect the entire engine wiring harness, sometimes it becomes frayed and shorted to ground. X25/2 also freezes on f105 F58. And try to disconnect the connector from the heating of the fuel filter, ventilation, M55 one by one and watch the power supply. In general, disconnect the components from terminal 87 one by one, so you will find the culprit of the short circuit.

 

[Mersovod]

Diagram for 5 wires in model 251 as 2011 year. Z14 powers 3 components... (power supply from N3/9 M (pin 56) color wires GYBK and RDBK).

• B70 Crankshaft Hall sensor
• B6/1 Camshaft Hall sensor
• Y27/9 Left exhaust gas recirculation positioner

 

[Mersovod]

When the EGR connector is removed, there should be nothing on pin 5. This means that wires 3 and 5 have a short circuit. There are only two power supplies 12V and 5V, you have 3.

 

[ber5ien]

Thanks for the info. I should try to disconnect these sensors first or try to remove that pin from the plug? So it will be only 4 pins for testing?

 

[Mersovod]

No. Disconnect plug M from N3/9 and Y27/9 and check the wires GYBK and BUWH for short circuit.