[speed2th]

2010 BMW 335d with 77k miles. SES light came up, shown glow plug control unit cylinder 5 malfunction. Purchase a replacement and took it to a shop to install it. The SES light pop up right away with new code U0106 and P064C code. The mechanic double check connection and had no idea why. I search the code and indicated it is very likely a power issue or unlikely a defective unit although i cannot rule out. Does any one know how to fix this or does anyone know if there is a fuse controlling the power supply to the glow plug control unit? The car has been running rich with poor mpg and lot of carbon deposit at back bumper.

thanks

[Mark M]

What's your running coolant temps? Thermostat failure seems to be common which leads to glow plugs operating too often and eventually burns them out. Coolant temps should be over 85c.

[TorqueAddict]

I Had to replace the glow plug controller to fix this when i had that code. Just for the heck of it, i replaced all glow plugs as well at the same time. As Mark mentioned, also keep an eye on the thermostat - it might be failing as well.

[Mik325tds]

This is a common failure on the 335d. Replace the glow plug module. It's easier if you pull your intake manifold but can be done without.

[speed2th]

yes the code came up immediately after the replacement. Did I get a dead module than? It was purchased from ebay and shipped from Europe.

[Owen81]

If the code came after he changed it, it wasn't plugged in correctly or you got a bad part. Why even buy the part used though? Its $105 with lifetime replacement warranty from FCPEuro

[Mark M]

Originally Posted by Owen81

If the code came after he changed it, it wasn't plugged in correctly or you got a bad part. Why even buy the part used though? Its $105 with lifetime replacement warranty from FCPEuro

Bingo....no point in buying used unknown parts when it is only ~100 new. Considering the labor on this job is a PITA, not worth cheaping out.

I did mine without pulling the intake manifold, but I have the scars on my hands to prove it. It is very TIGHT quarters working down there.

Please double check your operating coolant temps. The root of this is likely a bad thermostat. That's my wager.

[Owen81]

And if you're paying labor to pull the manifold, might as well do the glow plugs while you're in there

[speed2th]

Originally Posted by Owen81

If the code came after he changed it, it wasn't plugged in correctly or you got a bad part. Why even buy the part used though? Its $105 with lifetime replacement warranty from FCPEuro

It was a brand new unit.

[glitdi]

Have your mechanic actually do some diagnosis work...
1) take a digital multimeter and check for resistance in the glow plugs, compare resistances... Pretty much every glow plug I have ever checked is about 1ohm.
2)If that doesn't work get a hold of a wiring diagram and start checking the wiring...shouldn't be much to check. I believe the wire from the glow plug to the module is about it...If power before glow plug module was shorting you would most likely have all plugs out.
You have eliminated the glow plug control module, you probably have a perfectly operational spare now...

[speed2th]

Originally Posted by glitdi

Have your mechanic actually do some diagnosis work...
1) take a digital multimeter and check for resistance in the glow plugs, compare resistances... Pretty much every glow plug I have ever checked is about 1ohm.
2)If that doesn't work get a hold of a wiring diagram and start checking the wiring...shouldn't be much to check. I believe the wire from the glow plug to the module is about it...If power before glow plug module was shorting you would most likely have all plugs out.
You have eliminated the glow plug control module, you probably have a perfectly operational spare now...

thanks for respond. But the car drive ok and started ok, except it is running rich and have bunch of black deposit on my rear bumper. If glow plug is bad, would it have misfire? Also, is there a separated fuse that controls the module?

thanks

[glitdi]

Originally Posted by speed2th

thanks for respond. But the car drive ok and started ok, except it is running rich and have bunch of black deposit on my rear bumper. If glow plug is bad, would it have misfire? Also, is there a separated fuse that controls the module?

thanks

Not necessarily... Depends on the outside temperature. A misfire is not always due to a bad glow plug.. Its not a spark plug the engine might stumble on initial warm up but will be fine after it warms up a little. The glow plug module is can bus based..meaning the ecu communicates with it...If it was a power issue it would most likely effect all the glow plugs not one. If you had multiple glow plug godes out I would suspect a module. Ei cylinder 1 and 5 etc.... Just because its a common problem with our cars does not mean its the problem with your car.
Proper diagnosis is cheap! You know whats not cheap? BMW Parts....

[Yozh]

If you are running rich, you've got other issues you need to look at.

[speed2th]

I got it fixed now. I thought i read here someone said we should use GSE102 module, that is an incorrect part for 335d.
http://www.e90post.com/forums/showthread.php?t=1131874


My mechanic ordered GSE108 module and replaced all glow plugs, it solve the issue.