2004 Power & Control Box
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8th Gear
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2004 Power & Control Box
I have a 2004 Coupe, my check engine light came on so I took it to a dealer. They said there is a grounding problem with my power and control box. They are telling me they are going to have to replace it for a cost of $800. Does this sound realistic? They are also telling me it's ok to drive until the parts come in. If it has a grounding problem are there are areas that could be impacted or that they should be looking at? Thanks!
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First thing to do is see if there are any codes stored and can be displayed on the Driver's Information Center (DIC). If you're not sure how to pull the codes, check out the video contained in this thread:
https://www.corvetteforum.com/forums...ion-files.html
When you get all the codes, post them up and you'll get some good advice. I wouldn't do anything with the dealer until you do the above.
https://www.corvetteforum.com/forums...ion-files.html
When you get all the codes, post them up and you'll get some good advice. I wouldn't do anything with the dealer until you do the above.
Thread Starter
8th Gear
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Pcm
Thanks folks, I pulled up the codes and here's what I have. I have no idea how far back they go.
58 SDM U1000 H, U1016 H, U1096 H
99 HVAC B0367 H, B0446 H
A0 LDCM B2282 H, B2286 H, B2284 H, U1016 H, U1096 H
A1 RDCM B2283 H, B2287 H, B2285 H, U1016 H, U1096 H
A6 SCM B0851 H
B0 RFA U1000 H, U1096 H, U1016 H
Thanks again, Alice
58 SDM U1000 H, U1016 H, U1096 H
99 HVAC B0367 H, B0446 H
A0 LDCM B2282 H, B2286 H, B2284 H, U1016 H, U1096 H
A1 RDCM B2283 H, B2287 H, B2285 H, U1016 H, U1096 H
A6 SCM B0851 H
B0 RFA U1000 H, U1096 H, U1016 H
Thanks again, Alice
Thread Starter
8th Gear
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It was the check engine light that came on. I picked it up from the dealer yesterday and the light was off. They said the part should be here in a week. He said something about it not receiving a code and emissions not being in compliance which is why the light is coming on etc. I'll take it for a drive and see what it says. Thanks!
Thread Starter
8th Gear
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Pcm
OK, I cleared the codes twice and drove it a bit. The first time these Codes came back up 99 HVAC B0367 H & B0446 H, the second time this code came back up 99 HVAC B0367H. Thanks for your help! Oh, the check engine light has not come back on yet.
Thread Starter
8th Gear
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I did pull the codes before I shut off the engine, both times. I remembered the instructions you gave me earlier.
Melting Slicks
Joined: Jul 2013
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From: Anaheim CA
When you said "dealer", was it a dealer that actually sells/services Corvettes? Because none of the codes you had then (or now) have anything to do with the PCM, and in any case I would have expected any GM/Chevy service tech to refer to that part by its proper name, not "power and control box".
Sounds like the only thing that car needs is a better mechanic.
(And, for what it's worth, all that B0367 code affects is airflow to the passenger-side A/C vents.)
Sounds like the only thing that car needs is a better mechanic.
(And, for what it's worth, all that B0367 code affects is airflow to the passenger-side A/C vents.)
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Thread Starter
8th Gear
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Pcm
Thank you for the information. Unfortunately I'm not mechanically inclined. So I guess I'll let the folks that are take care of it. So I'm clear on it, the PCM is fine is just the valve that needs cleaned or replaced?
Melting Slicks
Joined: Jul 2013
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From: Anaheim CA
Are you a mechanically inclined individual???
The problem is simple. The valve for the secondary air system is crapped up and needs to be cleaned or replaced. There are two of these valves. One on the drivers side and when it malfunctions you get code P0491. It is easy to access and spray carb cleaner into to clean it out and then some WD-40 to provide a little lubrication for the spring inside the valve.
Unfortunately the valve on the passenger side is between the firewall and the back of the engine and VERY difficult to get at. It sets code P0492 when it fails..
The problem is simple. The valve for the secondary air system is crapped up and needs to be cleaned or replaced. There are two of these valves. One on the drivers side and when it malfunctions you get code P0491. It is easy to access and spray carb cleaner into to clean it out and then some WD-40 to provide a little lubrication for the spring inside the valve.
Unfortunately the valve on the passenger side is between the firewall and the back of the engine and VERY difficult to get at. It sets code P0492 when it fails..
Mine throws that code randomly, which my mechanic says is not uncommon. Typically it's once or twice in a two-week period, then not again for several months. Seems to depend on temperature/humidity (cool & damp makes the deposits on the valve stickier) and how often/far the car is driven (lots of short trips make it more likely).
Managed to get the smog check done a couple weeks ago during one of its "good" spells, so it's just an annoyance until 2017.
