BCU -- MAY BE CORRUPT ?

GJC

Active member
Jun 1, 2020
25
1
07712
My BCU has a permanent P1668 that can't be cleared. If I replace the BCU with another one, I would assume that this code will go away with the old one. In other words, this code is only stored in the BCU and not in the ECM ? I should be able to reprogram the BCU with my Nanocom? I need to find one that has similar mileage to the one we have now, although that's not that important. I just won't sync the BCU to my instrument cluster. I can just clear (stop) the flashing odometer. Any suggestions or thoughts?
 

Swedjen2

Well-known member
Sep 12, 2018
594
127
California
In some states like California where some modifications to your engine can send red flags to the Dept. of Motor Vehicles, like changing the ECU. I think the dealer has to reprogram the new one and let the State know you have an ECU different from your original and why it's different.

Can someone chime in and comment on how ones deals with changing the ECU if it goes bad and you get one from anyplace but a dealer in California or states with similar smog laws? I think N.Y. and several states around N.Y. are very strict regarding such things.
 

GJC

Active member
Jun 1, 2020
25
1
07712
In some states like California where some modifications to your engine can send red flags to the Dept. of Motor Vehicles, like changing the ECU. I think the dealer has to reprogram the new one and let the State know you have an ECU different from your original and why it's different.

Can someone chime in and comment on how ones deals with changing the ECU if it goes bad and you get one from anyplace but a dealer in California or states with similar smog laws? I think N.Y. and several states around N.Y. are very strict regarding such things.
I think the problem I am having is with the Body control unit (BCU). The P1668 is an immobilization code that I believe is within the BCU. I hope that I don't have to touch the ECM.
 

Harv

Well-known member
On my D2, the ECU was destroyed by water when we got it (very cheap, not running). We replaced both the ECU and BCU from a scrap vehicle, which solved most of the vehicles problems. I think on the D2 you can change just the BCU, but I don't know that for a fact. On the P38 they must both be changed.
 

rover rob

Well-known member
Mar 29, 2016
273
56
upstate NY
In some states like California where some modifications to your engine can send red flags to the Dept. of Motor Vehicles, like changing the ECU. I think the dealer has to reprogram the new one and let the State know you have an ECU different from your original and why it's different.

Can someone chime in and comment on how ones deals with changing the ECU if it goes bad and you get one from anyplace but a dealer in California or states with similar smog laws? I think N.Y. and several states around N.Y. are very strict regarding such things.
i live in N.Y. and every one of my d1s have had ecus swapped without any problems.
 
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mgreenspan

Well-known member
Feb 28, 2005
4,723
130
Briggs's Back Yard
Moved from CA recently. I don’t think you have to do anything extra if it’s a stock like for like ECU related item. You can’t add an aftermarket one that isn’t approved for use in CA just like exhaust or intake related components. As long as the OBD-II reads correctly and the vehicle passes a visual inspection it should pass in CA and not be considered illegal. If you have a non-compliant part visible it’ll fail even if it passes OBD-II.