stevneil
Active member
- Joined
- Oct 4, 2004
- Location
- Phoenix, AZ
On two of my three '02 TDIs, I've had the following fault:
17058 - Cylinder 4 Glow Plug Circuit (Q13) Electrical Fault
P0674 - 35-10 - - - Intermittent
or P0671 or P0672 or P0673 (the last number designates the cylinder number)
First, I reset the fault code, took it for a little drive and in front of the neighbor's house, the CEL/MIL comes back on.
So, off comes the engine cover, (yikes is it hot around that harness), and I made the discovery that is the reason for this post.
In removing the harness, I noticed that the boot on the reported plug was easier to remove than the others.
I checked the resistance on the plugs and all were 0.6 ohms so no problem there.
I removed the reported plug and, in both cases, noticed that it was more sooty.
I reinstalled the boots, making sure that they were all the way down (the last 3/32 of an inch is a firm snap). I noted that it takes quite a bit of pressure to get that boot fully seated.
I reset the fault code, and it never came back (well, 5,000 miles on the first one and only 10 on the one tonight but I am confident!)
So, I am surmising that the boot was not fully seated on the reported plug, resulting in two things:
1) insufficient electrical conduction between the boot and the plug causing higher amperage which throws the fault code, and
2) soot on the plug from not getting heated up sufficiently at every start and burning it off.
Three dealers have told me that they replace a lot of glow plug harnesses. My experience leads me to wonder if the true problem is that the harness is not being fully seated or pushed down in the factory, resulting in an eventual fault code or even a true failure of the harness from arcing.
What do you think?
--Steve
17058 - Cylinder 4 Glow Plug Circuit (Q13) Electrical Fault
P0674 - 35-10 - - - Intermittent
or P0671 or P0672 or P0673 (the last number designates the cylinder number)
First, I reset the fault code, took it for a little drive and in front of the neighbor's house, the CEL/MIL comes back on.
So, off comes the engine cover, (yikes is it hot around that harness), and I made the discovery that is the reason for this post.
In removing the harness, I noticed that the boot on the reported plug was easier to remove than the others.
I checked the resistance on the plugs and all were 0.6 ohms so no problem there.
I removed the reported plug and, in both cases, noticed that it was more sooty.
I reinstalled the boots, making sure that they were all the way down (the last 3/32 of an inch is a firm snap). I noted that it takes quite a bit of pressure to get that boot fully seated.
I reset the fault code, and it never came back (well, 5,000 miles on the first one and only 10 on the one tonight but I am confident!)
So, I am surmising that the boot was not fully seated on the reported plug, resulting in two things:
1) insufficient electrical conduction between the boot and the plug causing higher amperage which throws the fault code, and
2) soot on the plug from not getting heated up sufficiently at every start and burning it off.
Three dealers have told me that they replace a lot of glow plug harnesses. My experience leads me to wonder if the true problem is that the harness is not being fully seated or pushed down in the factory, resulting in an eventual fault code or even a true failure of the harness from arcing.
What do you think?
--Steve
