New bcm? Yikes!
Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
Likes: 0
New bcm? Yikes!
I have 04 base convertible. After taking out of storage this winter had to replace a dead battery. the next day the lights became intermittent and then would not even flip up. Dealer says I need a new BCM. How can that be, I said, if everything else works. Only current code I get is
40 BCM B2721 H C
about 20 other history codes.
Do I really need a BCM, quoted at $1550.00 installed, or is there some other things I should do first?
40 BCM B2721 H C
about 20 other history codes.
Do I really need a BCM, quoted at $1550.00 installed, or is there some other things I should do first?
Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
Likes: 0
I have all the codes will list shortly
RIPOFF TIME!!!!!!!!
Your first mistake was taking it to a Stealership. They want to STEAL your money because you are ignorant of codes and their meanings.
Here is how to pull your own codes:
OR
http://www.c5forum.com/ayc/dtcdic.php
Get to the car and pull the codes yourself and then POST ALL of them here including the H or C or HC that follows each 5 character code.
EXCELLANT chance that most if not all the codes are because of the dead battery.
Headlight problems are COMMON in the C5 and I have NEVER EVER heard of needing a new BCM to correct those.
Your first mistake was taking it to a Stealership. They want to STEAL your money because you are ignorant of codes and their meanings.
Here is how to pull your own codes:
OR
http://www.c5forum.com/ayc/dtcdic.php
Get to the car and pull the codes yourself and then POST ALL of them here including the H or C or HC that follows each 5 character code.
EXCELLANT chance that most if not all the codes are because of the dead battery.
Headlight problems are COMMON in the C5 and I have NEVER EVER heard of needing a new BCM to correct those.
Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
Likes: 0
The codes I pulled are as follows:
10 PCM p1631 H
40 BCM B0432 H
B0502 H
B0503 H
B0508 H
B2482 H
B2483 H
B2528 H
B2721 H C
AO -LDCM
B2282 H
B2286 H
B2284 H
U1064 H
A1-RDCM
B2283 H
B2287 H
B2285 H
U1064 H
A6-SCM
B0851 H
B0856 H
yeash.
10 PCM p1631 H
40 BCM B0432 H
B0502 H
B0503 H
B0508 H
B2482 H
B2483 H
B2528 H
B2721 H C
AO -LDCM
B2282 H
B2286 H
B2284 H
U1064 H
A1-RDCM
B2283 H
B2287 H
B2285 H
U1064 H
A6-SCM
B0851 H
B0856 H
yeash.
Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
Likes: 0
Ok will clear the codes and go for a ride tomorrow. The lights initially were up and on but then would go out but stay up. Now they don't even flip up. fog lights work fine. I don't know about the twilight feature but I don't think I have it. will check it out.
Burning Brakes
Joined: Sep 2003
Posts: 886
Likes: 87
From: Largo FL
When my BCM went out on my 97 I got all kind of random codes. Before I realized it was the BCM, went crazy trying to diagnose it. In the end bought a used BCM off ebay for $225, had a guy program it with a Tech II, and car has been perfect ever since. Don't let the dealer rip you off, not that big of a deal to fix.
Melting Slicks
Joined: Feb 2006
Posts: 2,938
Likes: 62
From: Columbia SC
Several years ago when I had first bought my 00 vert 6 speed it had several issues. The prior owner had let it sit outside for 2 years with the top ripped, thus it got wet. Took it to local dealer who said it needed a new BCM. They replaced the BCM and reprogrammed everything and all worked just fine. Total bill was $740.00 So I do not know where they are coming up with $1550. 
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Your getting excellent guidance. DO NOT let then talk you into BCM replacement. As far as I can see,, your BCM is fine.
Provide the info 8VETTE7 requested and I'm positive that you will get the answer you need.
Bill
Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
Likes: 0
OK. got done with a 12 today and took a nice ride. cleared all codes prior to leaving, checked codes with engine running when I returned. one code persisted.
40 BCM B2721 H C
I did not hear any grinding when the lights quit but I was driving, however the bulbs were intermittent when the lights were up before they quit coming up all together.
My twilight function is off.
everything else seems to be working well except an intermittent security light that stays on while driving from time to time.
40 BCM B2721 H C
I did not hear any grinding when the lights quit but I was driving, however the bulbs were intermittent when the lights were up before they quit coming up all together.
My twilight function is off.
everything else seems to be working well except an intermittent security light that stays on while driving from time to time.
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Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
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ya, I thought the key might be the prob for the security light, they are worn. I cleaned out the cylinder last year and they worked better but it is time for new keys.
the Headlight issue.
I was driving in early morning with lights on, the bulbs turned off but the headlight stayed up. I tuned them off they closed and when I turned them back on they flipped up and were lit. this repeated a couple of times but the second and third I had to repeatedly turn the lights on and off so that the bulbs were lit when they flipped up. then the they just wouldn't flip up at all. now when I turn them on there is no noise, and the lights do not flip up, all other indicators and running lights act as if the headlamps are on.
the Headlight issue.
I was driving in early morning with lights on, the bulbs turned off but the headlight stayed up. I tuned them off they closed and when I turned them back on they flipped up and were lit. this repeated a couple of times but the second and third I had to repeatedly turn the lights on and off so that the bulbs were lit when they flipped up. then the they just wouldn't flip up at all. now when I turn them on there is no noise, and the lights do not flip up, all other indicators and running lights act as if the headlamps are on.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
A couple of things that you should know:
1. - IF,,, you get a new KEY,, and you want a new SENSOR to read the resistor pellet on the key,,,,, YOU MUST order a new KEY CYLINDER. The sensor is part of the key cylinder.
When you receive the new cylinder, take the new cylinder and a NEW DEALER CUT KEY (Yes they can cut you a new key from your VIN Info) to the Lock Smith. The locksmith will re-pin the new cylinder to fit your OLD / New OEM key.
Its a little time consuming and expensive but,, one key will unlock the car, the ignition and be the correct resistance and the sensor will work.
2. - HEADLIGHTS. Your Steering Column "MULTIFUNCTION SWITCH" controls the Headlights and the Door Opening /Closing signal to the door motors. I my opinion,, It sounds like the Multifunction Switch is going bad. Its a pretty common problem and they do go bad.
Here is a Post that details repairing the Multifunction switch yourself:
- C5 Multifunction Switch repair - http://forums.corvetteforum.com/c5-t...f-replace.html
1. - IF,,, you get a new KEY,, and you want a new SENSOR to read the resistor pellet on the key,,,,, YOU MUST order a new KEY CYLINDER. The sensor is part of the key cylinder.
When you receive the new cylinder, take the new cylinder and a NEW DEALER CUT KEY (Yes they can cut you a new key from your VIN Info) to the Lock Smith. The locksmith will re-pin the new cylinder to fit your OLD / New OEM key.
Its a little time consuming and expensive but,, one key will unlock the car, the ignition and be the correct resistance and the sensor will work.
2. - HEADLIGHTS. Your Steering Column "MULTIFUNCTION SWITCH" controls the Headlights and the Door Opening /Closing signal to the door motors. I my opinion,, It sounds like the Multifunction Switch is going bad. Its a pretty common problem and they do go bad.
Here is a Post that details repairing the Multifunction switch yourself:
- C5 Multifunction Switch repair - http://forums.corvetteforum.com/c5-t...f-replace.html
Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
Likes: 0
great, thanks guys. I am going away this weekend but hopefully sunday night I can look at, and clean up, some grounds, will let you know what happens. In any event will stay away from the dealer and the $1500 bill.
Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
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OK checked grounds, they were actually quiet pristine, no corrosion, clean them up anyway and replaced. lights still not popping up. It looks like the headlight control module is cheaper and easier to replace than the mf switch. do you think I should start there or do the odds lie with the mf switch?
Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
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One more thing I noticed that I hadn't checked before. the bulbs light up with the lids down when I pull the mf forward for the quick flash. they do not light up in the low or high beam position. Does this in any way change the thinking on the mf versus the hcm?
Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
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Before I started replacing components I went through everything one last time. Grounds and fuses good, no other codes, no noise when headlight switch turned on. then I noticed if I pulled the mf switch forward the bulbs would light but the buckets would still be in the down position. I also had read a suggestion by dadaroo on another thread to try the twilight sentinel mode on - low and behold the lights flipped up and came on! This leads me to believe that the mf switch is bad and the signal to flip up and turn on is not getting through. I think this means my hcm is ok and definitely the bcm is ok. Unless you guys think otherwise I will swap out the mf switch for a new one.
Thread Starter
Cruising
Joined: Jun 2015
Posts: 13
Likes: 0
As I recall the MF switch new is fairly expensive. If you are a DIY person and like to tinker here are a couple threads about removing the MF switch (which you may want even it you decide to purchase new) and another on rebuilding the MF switch:
How to remove it link:
http://forums.corvetteforum.com/c5-t...-a-how-to.html
Repair link:
http://forums.corvetteforum.com/c5-t...f-replace.html
How to remove it link:
http://forums.corvetteforum.com/c5-t...-a-how-to.html
Repair link:
http://forums.corvetteforum.com/c5-t...f-replace.html
wow, great links! Thanks. I will check into how much a new one runs, it may be worth it to get a new one if it means I won't have to take the column apart again anytime soon. Thanks again for all your help I would be stuck with a new bcm and lights that didn't work if it wasn't for you. I also have learned a lot about my car by browsing this forum, it is awesome.