mbhouston

Hi,
Does anyone know where the glow plug control module is located? Any pictures will help. I have a 2008 ML 320 CDI.

Thank you,
MBP

Plutoe

There are loads of 320CDI variations--------what engine do you have?

mbhouston

Plutoe,
Thanks for the reply. I have an ML 320 cdi - 2008.

Regards,
MP

Plutoe

The module is located on the top front passenger side of the engine. It is bolted to the charge air crossover pipe.

When you find a glow plug, follow the wire back to the module.

mbhouston

Hi Plutoe,
Thanks for the reply. I will trace this back. A picture will really help me.
Regards,
MBP

isstay

look here:

mbhouston

I replaced the control.....works like a dream, CEL is now off. Cost was $130 for unit and 20 minutes to install.

Thanks for all the help.
MBP

2008 ML 320 CDI

I was 5 hours into a long trip when the glow plug light came on for a minute and then went off again. Three minutes later, same thing. Eventually, still on the same trip, the glow plug light came on and stayed on. The next day the vehicle started as normal, but now both the glow plug light and the CEL were on. Three days later the vehicle started to have difficulty to start when cold. The OBD II scanner gave an error "Communication to Glow Plug Control Module lost".

I replaced all 6 glow plugs and the glow plug control unit with new parts from the Mercedes dealership. I took care that the part numbers and the glow plug Voltage of the new parts were correct for the VIN of the vehicle and also that the new part numbers correctly cross referenced to the old part numbers. The glow plug light and CEL still remain on, or come back on even when the error code is deleted on the OBD II scanner. I checked all the fuses in the fuse box in the engine bay. No sign of damaged or loose wires or broken connectors. Everything in the engine bay is clean and in good order. I don't know what else could be wrong. Some help would be appreciated. Thank you.

kajtek1

codes ?

2008 ML 320 CDI

The scanner gives reading: 'U0106 Lost communication with Glow Plug Control Module'.

2008 ML 320 CDI

If interested, I have more photos and information on my issue in the link

2009 Ml320 Blu Tech cylinder numbers

https://mbworld.org/forums/m-class-w...r-numbers.html

kajtek1

https://www.obd-codes.com/u0106
Out of 5 possibilities this site list, 4 are bad wiring.
Get a can of MAF or other cleaner, wash all the plugs on the line to module and get good light to observe the harness for cuts.

2008 ML 320 CDI

Thank you very much kajtek1. The problem was indeed a poor earth wire connection to the cylinder head. After cleaning the wire lug and connecting surface on the cylinder head with some sandpaper, the error code, CEL and Glow Plug Light error are gone. The engine again starts first time like it always used to.


This earth wire connection was very slightly loose and just a little corroded. Cleaning and tightening the connection resolved the error code, CEL and Glow Plug Light error.

peter2772000

Glad you found it. I think I'll run thru my engine compartment this weekend and check for chafing and loose/corroded connections. This is a great thread.

2008 ML 320 CDI

Took some photos ...


New ceramic type Glow Plug takes an 8 mm tube socket.






Glow Plug locations on cylinders 1, 2 and 3.






Glow Plug locations on cylinders 4, 5 and 6.




















Set-up for doing some Voltage checks on the Glow Plug Control Module.






Voltage readings for each contact inside the socket on the Glow Plug Control Unit for the multi-wire electrical connector.

vitamin475

this data is of a good glow plug module? Or of the bad one?