Hi everybody, I've posted this to Mark's forum, but just in case if anybody has run into this same problem and have this solved, please help because I would like to fix it before I take my trip driving my Supra from Cal to Ohio next week.

I got the BCC like in February and finally had the time to get it installed. Everything works fine, I can now set my Profec B to 1.25 bar at Hi. However, the check engine light is on the very first time I push it over 1 bar (around there). I took it to the shop and the mechanic runs a diagnosis and he said it's the boost sensor triggering it. I tried to reset the ECU by 1st removing the negative battery terminal, doesn't work; and then I tried to remove the fuse, still no luck. What's the real cause and how can I solve it? I have BPU with hi-flow cat, GReddy 3-row FMIC, GReddy BOV. Thanks in advance.

The bcc is adjustable, what is happening is you are still hitting boost cut and that triggers the check engine light. Remove EFI fuses 1&2 for about 5 minutes and adjust the BCC please. Also, if the BCC is not soldered in, then you could have a problematic connection. ALWAYS solder connections if they are at the ECU area.

Mark Tozer
94 Supra 915HP
RPS T72
AEM Stand Alone
Black 6 Speed

Solder is the way to go!
YOu can refrence my site if you want to know how to go about doing it properly:

http://www.exhaustdepot.com/wiring101/wiring_101.htm

Did you read the tech articles on mkiv.com? It shows how to go about tuning the bcc.

Thank you very much for the reply. So, if I am still hitting the boost cut level and trigger the light, how come I can adjust my Profec B to 1.25 bar? When I switch off the Profec or even before the installation, the most I can hit is probably 1.01 bar at a very cool night. That's what I don't understand. Plus, is it hurting the engine?

Your profec problem is entirely a different thing than your BCC. To best tune your BCC, get a volt meter and adjust it to 4.2V. Your boost problem could be one of many including a boost leak. Check and make sure that all your hoses are connected as they should and there are no leaks.


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