Glow plug fault

[Shacks]

I have a 2004 E320 CDi on which the glow plug lamp on the dash comes back on after the engine has started. I connected my “MaxiScan MS509” scanner to investigate the problem but it shows no errors, is this normal as I would have thought that there would be a stored code showing which glow plug was at fault or some such error? The scanner looks to be working OK as going thru the menu it shows engine rpm etc OK, although I have owned the scanner for the last 3 years, this is the first time I have used it to fault find. I guess the next step for me is to get my DVM out and see if any of the glow plugs are open circuit.

 

[BTB 500]

Can't comment on your scanner but I know a dealer can tell via STAR which cyl. it relates to (having had two plugs go on the Vito).

 

[mersum1es]

sounds like incompatibility of scanner (nothing new when car is MB), but can also be control module of glow plugs and scanner cannot pinpoint the fault...

 

[notsofast]

I had a similar experience - My cheapo scanner showed no fault code but the glow plug warning light would come back on once the engine started for a couple of minutes.
Pulled the engine cover off and pulled the connectors from all the glow plugs and found open circuit on the last one checked with my multimeter. Bought six new glow plugs, the proper installation grease and a deep 8mm socket and had the failed plug swapped within a couple of minutes. Did not bother with the other five and no more have failed over the past few months.
The plug connectors are easily damaged and need quite a pull so it is worth buying a proper pair of pliers which hook under the cap and avoid damage. Also need a very light torque wrench.

 

[Shacks]

Finally got around to checking the glow plugs and number 6 is open circuit so I'm just going to replace this one. Thanks for all the replies.

 

[ahok19]

Finally got around to checking the glow plugs and number 6 is open circuit so I'm just going to replace this one. Thanks for all the replies.

Good luck Shack