Bad glow plug connectors?

ccmdude

Active member
Joined
Feb 5, 2010
Location
El Paso
TDI
2009 Jetta
So about 2 weeks ago my check engine light came on in my 09 jetta tdi. I pulled the code which turned out to be a p13d0. After researching the code on here, I bought a set of glow plugs off of eBay ( 03L905061F ). I probably should have swapped the glow plugs around first to ensure that it was the plug and not the harness but I didn't.
After replacing the plugs this past Saturday I thought I was good to go. Cleared the codes and they didn't come back that is until Monday morning. Now, all the cylinders have fault codes. Here's the kicker, while pulling off the glow plug wiring connectors all the bottoms of the connectors remained stuck on the glow plugs. I had to pull them off separately. I'll post a picture showing the connector without the bottom in a little bit.
I pieced them back together as best as I could but was missing three out of the four washers.

So the question is now, did I jack up the harness so that it's causing the new faults or does the problem lie with my eBay plugs? Thanks for the help guys.
 

kdawg89

Veteran Member
Joined
Dec 3, 2013
Location
Spanish Fork, UT
TDI
15 Golf DSG 06 Jetta (sold)
What brand of glow plugs did you get? Did they have part numbers stamped on the glow plugs themselves?


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oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Only use OEM glow plugs (most likely Beru, they will say on them).

You can buy the harness connector with wires by themselves and splice them into the harness, the part number is 03L-971-785-A however you must be very good about doing this, as those plugs are also cylinder pressure sensors, and the connection must be perfect in order for them to properly function.

That part number is only for one cylinder, if you tooefed them all, you'll need four, plus you'll need three red and one blue per cylinder heat shrink butt connectors, and some proper harness tape, N-105-920-02.

You can only use the proper type crimping tool with the connectors, anything else will just ruin them.
 

ccmdude

Active member
Joined
Feb 5, 2010
Location
El Paso
TDI
2009 Jetta
Ok thanks. I switched the plugs back to the originals this afternoon to see if I still get fault codes on all 4 cylinders. I'm hoping that'll tell me if the plugs or connectors are at fault.
If the connectors need replacing I'll let the professionals handle. Me and electrical stuff don't work well together.
 

ccmdude

Active member
Joined
Feb 5, 2010
Location
El Paso
TDI
2009 Jetta
So after I switch back to the old plugs I just have the cylinder #1 code. So I'm guessing my new plugs were bad. I've rotated the #1 plug to see if the fault moves with it. I'm thinking maybe I have one bad connector because I didn't label the original plugs when I pulled them so there's a 1 in 4 chance I put the same plug in #1 who knows. The adventure continues.
 

ccmdude

Active member
Joined
Feb 5, 2010
Location
El Paso
TDI
2009 Jetta
So now cylinder #2 is throwing the fault codes. I'm thinking the plug is bad. I've read you can replace one or all four at a time. Which do y'all recommend?
Also, I bought the 03L905061F which didn't work. What's the OEM part number for an 09 jetta TDI? I don't want to get the wrong ones again.
 

ccmdude

Active member
Joined
Feb 5, 2010
Location
El Paso
TDI
2009 Jetta
What's the difference between glow plug part numbers? The ones is my car are 03L905061D but the VW dealership sold me an H one. Online I've seen Gs & Fs. Are these all interchangeable?
 

N2UADTDI

Veteran Member
Joined
Apr 16, 2009
Location
New Jersey
TDI
2009 Jetta Sedan DSG
You can carefully glue the connector back together with a thick crazy glue. I used 'tire glue'. Bought at the hobby shop. A tiny tiny amount of the glue is all you need. Don't let it run into anywhere else except between the plastic parts.

These are complicated connectors that have to carry to the signal from the cylinder pressure sensor and carry high current to the glow plug heater.
The replacement connectors are expensive and time consuming to splice into the wiring.
Does the fault code indicate which glow plug (or sensor) is bad?
 

ccmdude

Active member
Joined
Feb 5, 2010
Location
El Paso
TDI
2009 Jetta
Thanks for the advice, I saved the part so maybe I'll try gluing them.
Originally it was cylinder #1 and then I rotated the #1 plug to #2 and the fault code shifted. I purchased a plug from the dealership (an H version) and replaced the faulting plug and it been good now for a few days. Fingers crossed it'll stay that way.
On another note, my car would take a few attempts to start up every once in a while. Battery sounded strong but it wouldn't catch until the second or third attempt. I assumed it was related to the glue plugs but it still does it every once in a while. I haven't had time to research solutions on this forum so I guess thatll be next for me.
 

N2UADTDI

Veteran Member
Joined
Apr 16, 2009
Location
New Jersey
TDI
2009 Jetta Sedan DSG
I tried to order the connector from an online parts dealer (03L-971-785-A). That part number is obsolete but has been replaced by 04L971785C. However they say that this 04L number won't fit my 2009 TDI. So I'm a bit confused. The webpage says it's the right part for the VIN but the parts guy say won't fit. Order was canceled.
Any suggestions? The parts guy says I have to order the entire engine wiring harness to get the correct connector.
 
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