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When you have a new CCM/BCM and it says that you need to have it programmed by the dealer before you drive 100 miles, what does the dealer program into it besides the VATS key code and the odometer reading? I purchased a used CCM/BCM and need to know if I need to have it reprogrammed or if I need to buy a new one and start from scratch. I bypassed the VATS so that is not an issue. I need to know if it cares about my engine, trans, power windows, door locks, etc. The two BCM serv numbers I have are different, but the dealer tells me they are the same part number.
The bad thing about buying a used one is the option content (ABS/ASR, C68 climate control, etc) may be different. If it is different, the CCM may not communicate with these options in your vehicle.
the only real problem I see is with the climate control.
A friend of mine said that his stock 90 Vette shift at close to 6000rpm. I connected my scanner and it showed more like 4000rpm. When I connected the diagnostic tool the CCM responded that it was LT5 engine but clearly he has a L98. Could it be that someone has replaced the old CCM with a used CCM from a ZR1 and the result is a tachometer that reports a too high rpm?
A friend of mine said that his stock 90 Vette shift at close to 6000rpm. I connected my scanner and it showed more like 4000rpm. When I connected the diagnostic tool the CCM responded that it was LT5 engine but clearly he has a L98. Could it be that someone has replaced the old CCM with a used CCM from a ZR1 and the result is a tachometer that reports a too high rpm?
that is quite possible.
depending on how it decodes the data, it sure could be a problem!
The used BCM is telling me I have a full tank of gas and I don't. It keeps flashing SYS on the display though and I can't track down any error codes that should warrant it. I do have error codes, but they were just for invalid passkey (used wrong resistor when I went to bypass vats), and open in the LCD dimmer circuit (I think that is because the radio is out). What would cause SYS to flash?
The dealer tells me that all the numbers for the BCM/CCM for 93 link to the same part number. I must have called 4 dealers and I can't get a straight answer from one of them. They tell me they want 1/5 hours to program a new one, yet no one can justify what they program or how it is done. We are supposed to trust these guys?
[QUOTE=test]The used BCM is telling me I have a full tank of gas and I don't. It keeps flashing SYS on the display though and I can't track down any error codes that should warrant it. I do have error codes, but they were just for invalid passkey (used wrong resistor when I went to bypass vats), and open in the LCD dimmer circuit (I think that is because the radio is out). What would cause SYS to flash?
The dimmer circuit is causing the sys flash. If you install an aftermarket stereo, you have to install a resistor with the correct resistance to prevent the sys. The other common cause of the sys flash is a weak battery. The sys is triggered anytime the ccm gets a voltage it doesn't like from the numerous systems tied into the ccm.
The used BCM is telling me I have a full tank of gas and I don't. It keeps flashing SYS on the display though and I can't track down any error codes that should warrant it. I do have error codes, but they were just for invalid passkey (used wrong resistor when I went to bypass vats), and open in the LCD dimmer circuit (I think that is because the radio is out). What would cause SYS to flash?
The SYS flashes if the CCM has a code stored, any code. Since you say you have codes then you will have SYS flashing. The only way to stop it is to track down the electrical problems causing the codes.