Genuine replacement Mercedes OM642 Glow Plug Control Module/Relay Pt No: - 642 153 20 79, 6421532079.
Is your Glow Plug Module acting up?
Or perhaps it has given up the ghost completely.
Time to replace it with this brand new genuine Mercedes Benz unit.
 
This module suits vehicles fitted with the OM642 turbo diesel engine including the following MB Cars:-
W203 Sedan                (2001 to 2007)
W203 Wagon               (2001 to 2007)
W204 Sedan                (2007 to 2013)
W204 Wagon               (2007 to 2013)
W209 CLK Coupe        (2002 to 2010)
W209 CLK Cabrio        (2002 to 2010)
W219 CLS Sedan        (2004 to 2010)
W211 Sedan                (2002 to 2009)
W211 Wagon               (2002 to 2009)         
W164 4WD ML             (2006 to 2012)
X164 4WD GL              (2007 to 2012)
W221 S Class              (2005 to 2018)
W251 R Class              (2006 to 2014)
X204 GLK                     (2009 to 2015)
W461 G-Wagon            (1991 to date)
W463 G-Wagon            (1990 to date)
May suit other models. 
 
This part is shown as no 10 in the diagram above
 
Original Part No:- 
A6421532079
6421532079
A642 153 20 79
642 153 20 79
642 153 2079
642-153-20-79
NSN 123755779
Superseded by:- A642 900 28 00
 
Don’t not pay over $600.00 for a genuine part from the dealer. Our price only $525.00.
NB:- this item is advertised on other sites and may be sold without notice.
 
Please check you have the correct part number for your vehicle.

Most parts available for all W164, X164, W171, W212, W221, W25, W461 & W463 Mercedes models.
 
McStarparts – “Keeping classic Benz’s on the road.”