2007 Glow Plug Module Test?

thewein

New member
I've done as much as I can based on what is out there and on these message boards. This morning the glow plug light and check engine light stayed on. Once I got to work I scanned the van and it came back with the following codes:
P0671 - Cylinder 1 Glow Plug Circuit/Open
P0673 - Cylinder 3 Glow Plug Circuit/Open

Codes were cleared and came back almost immediately. Once I got home I checked voltage, resistance, etc with a multi-meter and found:
- Open resistance on GP 1 and 5
- High resistance on GP 3 (200 Ohm)
- "Normal" Less than 1 Ohm on GP 2, 4, 6

When the positive lead is connected to the module with the 12 pin harness disconnected each of the GP pins on the module showed 12V at each pin with the key out of the ignition. It seems like the relay/module is constantly being powered. Is this normal? i.e. should this relay be normally open or closed?

We are supposed to be leaving on a road trip this weekend for 7-10 days and wondering what steps I should take from here:
a) replace the module immediately
b) replace the faulty GP
c) replace all GP
d) A + B
e) A +C
f) not go on the trip

Also wondering is there a good way to bench test the functionality of the module itself on its own without being connected?

If GP 3 is starting to fail - the resistance should continue to grow until completely open. Was thinking to monitor this over the next few days to see what happens to GP 2,4,6 and GP3.
 

smiller

2008 View J (2007 NCV3 3500)
You are on the right track. The module is powered continuously via a connection to the battery via a fusible link. A high-impedance VOM might show 12 volts on the module output to each glow plug when the glow plugs are disconnected but this is probably just a phantom voltage and doesn't mean much. The only thing meaningful would be voltage measurements with everything connected. Also note that supply to the plugs is PWM (not a constant voltage) so don't expect to see 12 volts when the plugs are powered. Checking the actual resistance of each plug (as you have done) is the right way to test.

You can go on the trip before replacing the plugs, there will be no harm especially in summer. When you get back replace the bad plugs and see where you are. If you are still on the original set of plugs some might suggest to just replace them all while you are in there, your call on that. If you remove the rubber head sound damper units be sure to be careful during replacement as it is easy to damage the plastic leak line fittings at the injectors. Also it's a lot easier to get to plugs 5 & 6 after removing the turbo inlet pipe so you may want to have a new o-ring on hand for reassembly. Do not use excessive torque when installing or removing the plugs; if a plug seems to jam on removal soak with solvent and slowly work the plug back and forth. Stuck plugs aren't as common on the V6 but it still pays to be careful. Use a torque wrench for installation.

You probably don't absolutely have to replace the controller but if you have a 2007 model and are still on the original controller module be aware that several updates were made over the years so it may not be a bad idea to replace it preemptively.

Use OEM or OEM-equivalent parts only, SD Euro parts is good source. Also when ordering the plugs be sure to get the correct plugs (and module if required) for your model year, around 2012 the plugs were changed and operate on a different voltage. Getting them mixed up will result in a bad day. There is a special tool you can use to remove the connectors at the glow plugs which makes things a bit easier, but it isn't strictly necessary.

Good luck, it's not a difficult job at all, just go slowly.

.
 
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bcislander

'07 Mercedes-badged Dodge
+1 on most of smiller's advice, but I would replace the GP controller before your trip, a very easy job. Then replace at least the faulty GPs after your trip.

OTOH, 'while you are there' replacing GPs 1 and 3, I would also recommend replacing GP #2. I did something similar when I replaced GPs 2 and 3, even though only one of them was faulty.

If you have to remove the turbo piping to get to #5, then you might as well replace #6 too. I changed a faulty GP #4 easily enough and decided to wait to tackle 5 and 6 until one of them failed. That was nearly 3 years ago. :smilewink:
 

Sinorm

Member
Agree with both of the comments above. You can go on your summer roadtrip without all the glow plugs working and it will be fine, but certainly get this fixed before winter. As they mentioned, check the model number on your glow plug module and replace it if you have the original. No need to replace all of your glow plugs, just replace the ones that are failed, and if convenient nearby plugs while you are in there.

https://europarts-sd.com/item.asp?cID=113&PID=1996

Module numbers:
A642 153 0379 (original installation)
A642 900 2800 (updated version)
A642 900 5801 (latest version)
 

BigBlueBus

New member
I have a 2007 3.0L with just over 60k now. I recently got 2 codes for bad glow plugs. Since my van most likely has the original module, should I replace the module as well? And if so, which version should I replace it with.
I already ordered 2 Bosch 80050 GP's., but now I've ready that I might as well replace them all while I'm in there. If so, what part number module and what part number GP's should I install.
Also, I've read conflicting threads that the engine should be cold or at normal operating temp before attempting to remove the GP's. Which is it?

Not looking forward to this project.
Thanks in advance.
 

smiller

2008 View J (2007 NCV3 3500)
I have a 2007 3.0L with just over 60k now. I recently got 2 codes for bad glow plugs. Since my van most likely has the original module, should I replace the module as well? And if so, which version should I replace it with.
I already ordered 2 Bosch 80050 GP's., but now I've ready that I might as well replace them all while I'm in there. If so, what part number module and what part number GP's should I install.
Also, I've read conflicting threads that the engine should be cold or at normal operating temp before attempting to remove the GP's. Which is it?

Not looking forward to this project.
Thanks in advance.
If you have a 2007 on the original controller then it probably isn't a bad idea to update the controller to the current revision. You will get the current rev. controller if your order from your dealer, or from SD Euro parts (just make sure that you order the unit for 2007-2012 models.) Likewise while 'replace 'em all' is a judgment call, on a 2007 it's also not a bad idea so that you aren't going in there again next year. You might want to test the physical resistance of the bad plugs with an ohmeter (there is a good instructional video on YouTube) to confirm that they are bad. They probably are.

Replacement is really not a difficult job, you do need to remove the turbo inlet pipe to get to plugs 5 & 6 but that's pretty straightforward (you will probably want to have a new o-ring seal on hand.) There is also a special tool to remove the electrical connectors from the top of the plugs but it isn't strictly necessary to have.

Stuck plugs is not usually a problem on the V6 but it can happen, just remove carefully and if you hit any significant resistance work the plug in and out and go slow. I removed mine with the engine both warm and cold and noticed no difference, all came out easily and with no drama at all. Use a torque wrench for installation.

As long as all the plugs come out easily (they probably will but ya never know) then it shouldn't take more than a few hours the first time out.
 

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