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Old 11-21-2019, 08:58 PM   #6
imaddicted2u
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Join Date: Jun 2013
Location: Nova Scotia
Posts: 519

2008 AURA XE
Default Re: dash cluster swap solved problems

Quote:
Originally Posted by fdryer View Post
It may be that anti tampering laws against illegal odometer alterations are controlled at the chip level regardless of VIN. Since the bcm contains mileage and proven intact despite many stating they're electronic shop of choice can alter mileage on used bcms with none reporting actual success, I tend to think the chip on the instrument panel that increments the display is a simple count-up device and designed not to count down. The example of finding the original i/p plugged in and immediately displaying corrected mileage from the bcm when it was removed verifies this. The higher mileage i/p couldn't count down but I'm certain will count up when bcm mileage catches up to this i/p. Wait until the mileage accrues to match or exceeds the i/p mileage then plug it in.
Actually the BCM and the Instrument panel odometer work together. When new, the cluster can be moved between vehicles and it reads the mileage stored in the BCM of the vehicle it is currently installed in. However, the instrument panel cluster becomes locked to the vehicle VIN after a certain number of ignition cycles. It draws the odometer reading from the BCM and is stored in the non-volatile memory in the Instrument cluster. In the event of a BCM failure, the new BCM receives the mileage from the cluster once the VIN is programmed in to the new BCM and it matches the VIN stored in the instrument cluster. The cluster itself does not "count" mileage, the BCM does that nowadays and passes that as digital data to the cluster. It will not begin to count up when the mileage catches up.
This was covered in an old thread by Greenman with info from GM.
http://www.saturnfans.com/forums/sho...5&postcount=23
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2008 Saturn Aura XE 3.5L 4 spd
2000 Saturn SL1 1.9L SOHC (Retired)
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