View Full Version : 2003 VW Jetta Glow Plugs

11-21-2007, 12:59 AM
I have a 2003 VW Jetta that the check engine light has came on. I took it to Autozone and they checked and got a P0671 OEM number returned which indicates cylinder 1. The three choices that their printout showed were:

1. Poor electrical connection
2. Failed Glow Plug
3. Glow plug control system fault

I checked the plug electrical connection after locating cyliner one in my 1999-2002 manual. It seemd to be connected good. I bought and replaced the glow plug. The check engine light still comes on after about 30 seconds or so. I might also mention that I replaced all four glow plugs back in July of this year already. What would the third option about the glow plug control system fault indicate and what could I do to remedy the light coming on. Thanks for any and all help.

11-21-2007, 04:56 PM
Hi PThomas,

The glow plugs get their power from a glow plug triggering module which is controlled by the Engine Control Module (ECM). Since only one of the glow plug circuits is acting up, it probably is not a problem with the ECM. Of course, it could be a wiring problem between the glow plug control module and the glow plug, or between the glow plug and ground.

It's very difficult to try to diagnose something like this remotely, but these are a couple of the possibilities. Just remember, before purchasing any parts, that electrical parts are non-returnable. If you can't find any obvious problem, it might be time to turn the car over to a pro.

Hope this helps, and good luck!