My 3 year/36,000 mile bumper to bumper expired, but I still have the 100,000 mile engine warranty, however, there's a $100 deductible. I was wondering, if the truck has already had the update/reflash for the recall/TSB on the glow plug, then what else could it be? It says glow plug cylinder or #8. Can someone please shine some light for me?

I just got done going through the exact same thing, same cylinder code and everything. My truck didn't have the GPCM reprogramming issue because it's an '07 and because my lift kit and all. They said the hoop was in the way,s:blahblah:, I ended up getting a couple Bosch replacement plugs and just removed the 6th and 8th plug. When I started to remove the nut attaching the wire to the plug, the nut and threaded end snapped right off :eek:. After I put in the new one and cleaned up the connector a bit, it worked just fine with no CEL light. It was just severally corroded and was making a bad connection.

Mine was rusty, but it definitely wasn't corroded so to speak. I did clean it up and reinstall it. Cleared the code and I'll give it a shot tomorrow morning to see if it holds up.

Would doing a continuity check on the glow plug prove to be bad or good? Meaning, if it makes continuity, does that mean it's good?

I couldn't say for sure, Im by no means an electrician. However, if you plug was rusty, that could easily be the issue.

Does anyone know how to test to see if one is bad? Would continuity be sufficient? I don't want to assume it's bad and buy a new one.

I dont know 100% about a glow plug for diesel but a glow plug for a gas furnace, boiler etc.... continuity means its good not bad. I would put my money on that if you have continuity its fine. The other idea would be to test one you know is good.

LOL Well of course if it has continuity is completing the circuit and more than likely good. My question was, is if it does complete the circuit, does it necessarily mean it's good. I ask because I was reading that it should get somewhere around 4.7 volts, but my voltmeter was only ready like 3.5 volts.

Late reply, but it ended up being the glow plug itself. It was bad. Did a continuity test on it, showed to be bad. I verified this with the new plug. $29 and I'm back in business. Easy to do with the wheel liner out.

06DMAX00CAMSS,

Glad you were able to correct the issue.

I had a similar situation with the reprogramming completed at 7150 miles and a P0671 code show up. It was the #1 glow plug. After reading several posts as well as this one, I checked the resistance and it was 24 ohms on that #1 plug. All the others read .6 -.8 ohms. A few others had noted that theeir glow plugs were replaced under the emissions warranty. I looked it up in my warranty book and it states that the glow plugs are covered (5Yr/50,000mile emissions warranty).

Lucky me I am at 46,700 miles. I also read on another post that if one glow plug shows a resistance over 1 ohm that GM must replace all 8 glow plugs (PIP3586C).

Called my service advisor Monday and told him the situation and made an appointment to take the truck in on Tuesday morning. Got the truck back today and indeed it was covered under the emissions warranty and all 8 glow plugs replaced with no cost to me.

Here is the info on the ticket:

A SES light on
Cause: A glow plug has high resistance
J4767 plugs, glow (diesel) both replace

Part #: 97364968
Count: 8

Glow Plug on Cylinder#1 had high resistance.
Replace all the glow plugs per PIP3586E, clear the code and road test.

Just thought I would share the info I found.

Best of luck and thanks to all who have posted about the glow plugs.

Derrick