rickf2757

Have 105k mi on this car. CEL lit, glow plug light re lights for about 10 seconds after start. No other problems. Pulled p0670 code, which seems to be generic code for glow plug +/or controller problem. I assumed one or more glow plugs failed, so replaced them all with Beru 5v. Same cost as diagnostic visit at dealer. Problem is, all of the plugs were fine, problem and CEL remain. Anyone have insight or experience here?

mersum1es

faulty glow plug controller?

(Sure glow plugs were right type?)

japper

Glow plug module is unfortunately more common to fail then the glow plugs on these CDI engines. Double check what type plugs you have, there are some CDI engines with more expansive ceramic plugs. So controller or plug mismatch can fry the controller/module.

rickf2757

Thanks for both suggestions. I'll likely just replace the control module like I should have done anyway. I'm sure they were the right plugs. Replacing #4 was a bear. Just glad I didn't break one.

Plutoe

Hey before you waste more time and money why not determine what the OBD fault is before throwing the baby out with the bath water!!

rickf2757

Finally got around to getting proper detail on ODB and diagnosis was controller module. Other posts on this site helpful on location and replacement. No way I could replace from above, just jacked up the car and accessed from underneath. Still a bit tight, but was able to replace it using 8 mm box end wrench an much patience. Glow Plug pigtail no longer stays on and CEL no longer lit. Part cost $235, dealer quoted me $700 for the repair. No way I could or would have tackled this without the advice and info found on this website.

turbo97se

Could you share where you got the part? I just bought one on line .. it was more than $235 ... just for future reference if I need other Merc parts ... thanks

rickf2757

Ordered it from genuinemercedesparts.com. $235 + $30 shipping.
Good luck.

Plutoe

"No way I could replace from above, just jacked up the car and accessed from underneath"

Wow is that loads of work---the procedure is from the top--remove engine cover--remove four bolts and a nut--pull the module forward and remove connector--slide the module out---reverse the process for install!!

mersum1es

I wonder why they put that in near gear box? I am pretty sure in European models it is in engine bay, top of the left front wheel...

turbo97se

I was wondering if you have pics or detailed instructions about this? When I check the WIS, there is no way to do it from the top as it appears to be attached somewhere close to the bell housing near to the transmission some say to the underside of intake manifold. Why on earth they put it down there I do not know .. it appears to be up top on other models (including European W211s I believe). There is no lack of space up top.

Plutoe

The information I provided was based upon the OP's car---put your VIN in WIS and do the same search---wada you get!!

FYI---there are loads of differences and that is why you always check by VIN and not your girlfriends tele number!!

turbo97se

I was wondering why my girlfriend's number wouldn't work!! ... OPs car is clearly a US model (Beru 5V plugs). I obviously entered my VIN (from the embedded pic) and it also is a US model. The only access is from below, just did this today.

rickf2757 thanks for the info on the part.

dave2001auto

Modules come in various volts for ceramic glow plug and steel glow plugs. Don't mix. I read from the Sprint board of a two set of gp before the mistake was realized. Poor guy :{ The EPC or dealer can advise you based on the VIN and keep records. By the way how did the estimated diagnosis cost the same as replacing all the glow plugs?

On my 2009 e320 bluetec, the glow plug module failed (glow plug had the right resistance). During the diagnosis on of the air intake line fell off giving a limp home and air-flow mass code. Replaced air gasket and glow plug module. Glow plug light was okay, but now giving a Check Engine P3237 code. Also sun roof and CD/radio are acting up. Sync was partially successful and CD is stuck as if seeking disc and can not eject disk. Also the radio has a long delay when starting the car. How to fix?

Additional Info. Removing the battery and reconnecting fixed much of the computer check light gremlins. CD/radio player still same problem, but taking about 2 minutes before radio will turn on. I tried tapping on the CD while it's trying to eject, but it didn't work. Anybody replaced with one from ebay or a good rebuilt one and where to buy?

dave2001auto

Lots of dealer have discounted parts on line. Usually 20% off MSRP. mbonlineparts is a board sponsor. They charged me $17 to ship across country, but to a very old address. I suspect if they would of shipped locally to to correct address, it may of been less cost. $235 sounds like very good price for your module.