P0380 Glow plug malfunction/ Did all checks from Glow plug 101. what now?

vdubdezl

Veteran Member
Joined
Sep 19, 2007
Location
FL
TDI
06 Jetta TDI 5MT, 05 Honda Odyssey EX-L
01 Golf TDI automatic
I did all of the checks according to the Glow Plug 101 Ver 2.0 and came up with one bad(resistance wise) glow plug. Replaced it and no change. Unplugged the ECT and it stayed on longer, but has no voltage on any of the four connections for the glow plugs. It has the two wire harness. According to the GP101 it is the relay that is bad. I took apart that #180 relay in position 10 and left the case off of it. It would not cut on during initial key on with ECT plugged in but would lock in while cranking and stay locked in while it is running. Is this right for this relay? Is this the right relay to check?
 

vdubdezl

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Joined
Sep 19, 2007
Location
FL
TDI
06 Jetta TDI 5MT, 05 Honda Odyssey EX-L
I pulled the relay out and checked the pins. All of the pins look like they are where they are supposed to be and not corroded. I have a Haynes manual and checked the wiring according to it, but it is missing a couple of the wires that I have. Here are the colors of the wires and their voltage output (key on).

Red: 12.2v from firewall
Purple/white: 3.5v This wire comes from the ECM
Red/white: No voltage (showing ground through my Power Probe, which means it is making connection through the glow plugs)
There are two of these to power my two wire glow plug harness.
Blue:12.2v key on battery voltage
Green:10.75v I don't know what this one is, but I think it is a voltage drop from a relay. Or is this the problem?
Brown:No voltage (showing through my Power Probe)


Really would like to figure this out!
 

elroy

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Jul 6, 2010
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pickering
TDI
2003 Jetta TDI GLS
If your not getting power to the harness then it does sound like the relay. That being said, is the harness melted together anywhere. Do you have 12v leaving the relay to the harness? If you can find someone locally to swap the relay over, that'll help you eliminate the relay issue or pinpoint it as the cause.
 

vdubdezl

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Joined
Sep 19, 2007
Location
FL
TDI
06 Jetta TDI 5MT, 05 Honda Odyssey EX-L
If your not getting power to the harness then it does sound like the relay. That being said, is the harness melted together anywhere. Do you have 12v leaving the relay to the harness? If you can find someone locally to swap the relay over, that'll help you eliminate the relay issue or pinpoint it as the cause.

No, I don't have 12v leaving the harness because the relay never clicks on with the key on(with ECT plugged in or not). I can crank up the car and the relay will kick in and stay in with the car running. I am afraid that it is the ECM. :(
 
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vwdieseling

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Apr 5, 2012
Location
Lima Ohio
TDI
Beetle, more bugs
I would fork over the money and buy a new 180 relay. It sounds like your getting this problem out of proportion. I know they're expensive, but it probably the problem. My 2 cents worth, good luck.
 

vdubdezl

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Joined
Sep 19, 2007
Location
FL
TDI
06 Jetta TDI 5MT, 05 Honda Odyssey EX-L
I ordered the relay from IDParts and we will see how it goes.
 

vdubdezl

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Joined
Sep 19, 2007
Location
FL
TDI
06 Jetta TDI 5MT, 05 Honda Odyssey EX-L
Just got my EGR cooler on after having it deleted since August. I had cleaned the battery cables before and this code went away. Before that I replaced the relay. I just cleared them again after replacing the cooler and the code is back. Any ideas? I have done all of the checks on Glow Plug 101. I will have to pull the glow plugs out again and recheck them.
 

vdubdezl

Veteran Member
Joined
Sep 19, 2007
Location
FL
TDI
06 Jetta TDI 5MT, 05 Honda Odyssey EX-L
Checked the ohms on the glow plugs and all of them are 1.1. Cleared the code. Going to see if it comes back on.
 

vdubdezl

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Joined
Sep 19, 2007
Location
FL
TDI
06 Jetta TDI 5MT, 05 Honda Odyssey EX-L
The light, of course, came back on. I did some other checks and found corrosion inside the ring terminal at the battery for the glow plugs. Apparently, it would not handle the load when it was put on. So far has been off for three days now.
 

Metalhead

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Joined
Apr 23, 2012
Location
Rochester NY
TDI
2000 Jetta TDI
What is the ring terminal at the battery? Because I have an annoying glow plug light too, I made my own harness, replaced all the glowplugs... get 12 volts at the harness. Hopefully I have the same problem.

Thanks
 

jayb79

Top Post Dawg
Joined
May 20, 2000
Location
Exeter,NH
How do the harness sockets look? If the look bad you may need a new harness. Do you have a connection inside the conduit(race track) that holds the wires going to the relays? The connection in there have know to sometimes be a problem(melted).
 

vdubdezl

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Joined
Sep 19, 2007
Location
FL
TDI
06 Jetta TDI 5MT, 05 Honda Odyssey EX-L
I think it is the third one over from the left. Open the battery cover with the four wires going in on top of the battery. On the side going away from the battery is where it takes the load to the relay. The ring terminal bolts down on the other side of the strip. I unbolted mine and in the inside of it was corroded. I also had problems before with the main engine ground under the battery and where it bolts to rear of the engine got corroded. Neither one looked like it was a problem, but cleaned both with a wire brush and that fixed it the last time. Remember you HAVE to clear the code out whenever you repair something. Did you do this??
 

Metalhead

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Joined
Apr 23, 2012
Location
Rochester NY
TDI
2000 Jetta TDI
Thanks for the help, I already checked the ground under the battery, it looked bad from the top, but upon removal of the bolt, the threads were perfectly shiny. I still sprayed them with some electronics cleaner and got some of the corrosion off. I'll check the wire on the top of the battery.

Jayb, What connection are you talking about? That sounds interesting. Do you mean the wires that go to the glowplug harness? Because I had been trying to trace those, and had a hell of a time. Couldn't figure out where they went...
 

vdubdezl

Veteran Member
Joined
Sep 19, 2007
Location
FL
TDI
06 Jetta TDI 5MT, 05 Honda Odyssey EX-L
I still have the CEL coming on for this and it has been a year I have had the car. Getting really tired of it. I just took apart the whole harness and checked the connectors. All of the connectors looked great but I cleaned them with contact cleaner anyway. I think I may try the "ghetto" mod for the harness that Jaybe79 mentioned next.
 
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