02 GMC 2500HD

Hi, Just to put a final answer for my particular truck cold-weather starting problem: My fuel pump was dying and finally died for good. Replaced with new one and no starting problems since. Thanks for everyone's help!

The inner part of the AC pulley is really hard to turn, the outer was very easy. Oh well, looks like no AC for me! Thanks for the tip davester!

Will do! Thanks davester

davester, Thanks for the heads-up about the computer and alternator! Look like I got me some learnin' to do. I'll also check all the things that spin with the belt - I noticed that the AC belt was missing (I didn't even think to check if the AC was working because it was November when I bought it - that was dumb of me) and the tensioner pulley wouldn't spin by hand. Not that I really care if I have AC or not in this truck, but I'll probably replace the tensioner and belt just for kicks and see if it does work. Thanks again for the replies!

Changed out the alternator and belt this weekend - it took about 15 minutes (only 2 bolts and 2 connectors - I wish changing out parts were always that simple) and the hardest part for me was getting the new belt in place. I'm glad I replaced the alternator as I think the bearings are on their way out - when I spun the pulley it felt gritty. But I also noticed that the lights are still slightly pulsing, so it wasn't the fix for that. The belt looked OK, but I don't know how old it is. Still no starting problems this weekend and I'm not sure what to do next, so at this point I'm just going to cross my fingers and wait until it happens again. I'll update again when/if it does and post a fix if I find one.

Hi davester, Thanks again for your reply. I like the idea of a battery warmer and will look into it. It was 19 degrees F this morning and again, the truck started right up with no problems. The P0300 code is gone but the P01637 is still present. However, the alternator was making a little noise and got louder with increased throttle, and I also noticed that the lights (interior and exterior) were pulsing slightly. They would get a little brighter with increased throttle, and would also continue to pulse slightly during idle. Not sure if this is related, but for my piece of mind I'm going to just replace the alternator and belt this weekend. Looks very easy to do. At worst this doesn't fix the starting problem and I have more diagnostics to do. At best, it does fix the problem and I have a spare alternator that I can look into/learn about rebuilding. Again, I'll try to keep this thread updated with my saga in case it helps others.

Hi CamGTP and davester, Thank you for your replies! Wouldn't you know it - the truck started right up last night like nothing was wrong. Turn the key, barely any cranking time, and fired right up! I was able to pull some codes: P0300 (Random Misfire) and P01637 (Generator L-Terminal Circuit). I understand the P01637 is tied to the alternator (or the wires going to the alternator?), but I see the needle on the dash voltmeter is swinging past 14, which I'm assuming means it's charging the battery? Does anyone know if the P01637 code would cause a no-start condition? So I guess the next possible steps would be: - Pull the alternator and get it checked. I have no idea if it's ever been replaced or if it's the original one. - Replace the alternator anyway, since I have no idea if it's original. - Check the wires going to the alternator - anyone have any idea how to check these wires and what I'm looking for? One other variable in this equation might be the weather/temperature when I tried starting it last night - it was a bit warmer than the last time it wouldn't start - it was about 35 degrees F, as opposed to about 25. Would a +10 degree change make that much of a difference? But, the funny thing is it started right up a bunch of times previously when it was much colder (- 10). I'd like to try and get this starting thing sorted out, because now I'm getting a little worried about the truck stranding me - especially if I have the bed loaded with stuff and/or towing something... Or, if I have the wife with me - I'd never hear the end of it. Also, I intend to use this truck to snowplow my driveway next winter, and it tends to get a bit COLD in upstate NY when it snows... I'll try to keep this thread updated, in case it helps others who may have similar problems. Thanks for any thoughts, suggestions, and ideas.

Hi, I know this topic is a bit old and there are already a few threads on similar issues, but it's happening to my truck now too. A little history on my truck: 2002 GMC Sierra 2500HD SLT, extended cab, 4WD, 6 liter, automatic, snowplow package, 130,000 miles. I bought it back at the end of November last year. I got it "for a song" because it had codes PO171, PO174, and PO300 and the owner just wanted to get rid of it. I found that the 171 and 174 codes indicated a vacuum leak and were caused by leaking intake gaskets and holes/cracks in the EGR tubing. I changed out the gaskets with the steel Fel-Pro (not technically hard to do, just a pain for my back and remembering what goes where when putting everything back together), replaced the EGR tubing, changed out the spark plugs and wires, and put a new battery. Cleared the codes and they never came back - truck never failed to start so far, even in -10 degree F temps. Yesterday I tried starting it and it just cranks and cranks, almost catches, but doesn't. When it almost starts (but doesn't) the engine makes a weird sound - almost like a deep exhale or sigh. I've checked the fuel pressure with the key on (I can hear the fuel pump prime) and it's at 50 PSI, which I understand is within range for my engine (the throttle body is not "fly-by-wire," it actually still has a cable actuating the throttle blade), and almost no bleed down - the pressure stays up there for quite a while. The security light doesn't stay lit (although it reminds me to change the oil), so I don't believe it is a VATS or Passkey issue. I've tried starting it with my foot off and on the pedal, disconnected the MAF, re-connected the MAF, added gas to the tank so it's on half full, and even tried shooting starting fluid in the throttle body - won't start. Any ideas or suggestions? I can be a little handy with engines (can follow instructions at least) and have some tools. Thanks for all your help.

Hi All, It worked (I think)! I was able to get the intermediate cable attached to the right rear cable. I just have not been able to get the parking brake pedal to return to the fully up position when releasing it yet. But I still need to check for the parking brake shoe clearance, which should be fun with all the rust... Gotta love upstate NY snow! Thank you again for all who replied to my questions. I hope to return the favor!

Hi All, It worked (I think)! I was able to get the intermediate cable attached to the right rear cable. I just have not been able to get the parking brake pedal to return to the fully up position when releasing it yet. But I still need to check for the parking brake shoe clearance, which should be fun with all the rust... Gotta love upstate NY snow! Thank you again for all who replied to my questions. I hope to return the favor!

newdude, Thank you - that's the piece I was talking about that I didn't understand. And thank you for the procedure! I'm going to tackle it this weekend. Thank you to all of you who replied - this is a great site and I'm glad I joined!

Hey guys, Thank you for all your helpful comments! "The main cable has a sort of hood on it with a slice, where the other cable joins it. That "hood" is then pulled by the front cable. I will post a pic tomorrow" Formulabruce - your description sounds just like what I'm seeing - your pic will be very helpful! Thanks again!

Hi Formulabruce, Thank you for your reply. I can see what you're describing - the intermediate cable only attaches to a single rear parking brake cable? How does the other parking brake get activated? The picture below is what would make sense to me (I believe this is the equalizer, and not included in the cable I bought because it said this was for trucks without RPO code HVY). If it's just the single connection, then I think I'm good - I then just need to figure out how to get some of the front cable to spool out from the parking brake pedal mechanism... Thanks again for your help.

Hi All, I'm a new member and hoping to use all of your vast membership resources to help me out. I bought a 2002 GMC Sierra 2500 HD extended cab with the 6 liter a few months ago and am trying to get it ready to pass inspection now that he weather seems to be getting a bit less frigid. It's got 130,000 miles and seems to still run strong. I had some codes when I got it and traced the cause to the leaking intake manifold gaskets, which I replaced on my own with the steel fel-pro gaskets - no more codes. My current problem is that the intermediate parking brake cable was snapped, so I bought a replacement cable. Was able to take off the old cable and attached it to the front cable, but I don't understand the how it attaches to the rear cables. It looks like there are 2 cables, one going to the rear left, and one going to the rear right parking brakes, but it looks like only one of the cables can attach to the back of the intermediate cable. The truck has the HVY RPO code (2 inch lift), which I understand (or am completely wrong) does not have an "equalizer." I can't seem to find any diagrams/schematics/pictures of what this connection looks like - could anyone who has a similar truck please take a few pictures of what that connection looks like and post it here? Thank you for your help.