Caldina exhaust flap control

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Caldina exhaust flap control

Postby GDII » Mon Aug 26, 2019 11:26 am

I know this place is rather quiet but I'm not a facebook user or want to sign up to a Caldina forum to ask quite yet.

I'm looking at the ST215 3SGTE Caldina exhaust flap in the rear muffler and trying to figure out how it is controlled by the ECU.
There is a BPC+ and BCP- pin on the ECU for controlling the actuator but I am unsure of the exact parameters it uses to apply a signal to these pins.

What I want to know is:
1. Is it RPM and throttle position dependent?
2. Is it coolant temp controlled (for emissions) and opens after the engine is warmed up enough? An odd theory.
3. Is is variable using a stepper motor in the actuator unit?

For now those seem like they cover possible ways to control it.

I don't have access to a car to test it or even observe the operation of the valve.

The reason I ask is, I want to swap in the 3SGTE into an SW20 MR2, as many do, and possibly utilize this output for external control of something. Like intercooler water spray or something similar. This would only work if it was as per question 1.
1990 SW20 MR2
Previous 1990 EE90 Corolla
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GDII
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Re: Caldina exhaust flap control

Postby BlakeNZ » Tue Aug 27, 2019 2:43 pm

I asked my Caldina/MR2 mate about this, he said
"Im pretty sure its for emissions and is coolant temperature controlled- helps heat the cat faster "
former car 1991 JZZ30 soarer 1JZGTE 11.5sec@122mph(stock turbos,E85)
current car 1993 JZZ30 soarer (Golden Boy)
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Re: Caldina exhaust flap control

Postby GDII » Tue Aug 27, 2019 5:24 pm

Oh damn. Not quite the answer I wanted but thank you.

I have a JDM wiring manual coming in the mail soon for the Caldina so maybe it gives a bit more insight into how it works with the coolant temp. I'm sure I can find something to use it with. Maybe even intercooler fan switching so the stock control system can be removed but the fan doesn't operate when the car is cold.
1990 SW20 MR2
Previous 1990 EE90 Corolla
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GDII
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Posts: 1642
Joined: Wed Aug 22, 2007 4:13 pm
Location: Wellington


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