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Hardware For One Wire Vtec

Library.HardwareForOneWireVtec · r1.3 · · tatou100

First, let me give credit to Jason Parker for coming up with the parts list; I finally laid my hands on a PS9 to get the part values.

To mod the PM6 (and likely similar OBD0 ECUs) to allow them to do the 1 Wire VTEC control, you have to configure them as if you were converting from Manual to Automatic.

Here are the components I have documented:

C77 - .01uf Ceramic Disc Capacitor

IC17 - 8055P (available in PM5 auto ECU or PM6)

Q42 - NEC D1594 - Actually a 2SD1594, but unable (so far) to find a direct cross in US, but available in PM5

Q16 - C945 - Actually a 2SC945, it crosses to an NTE85

Q28 - NIL3Z (can be borrowed from PM5 DX ECU, lots of them)

R62 - 10K, 1/8W

R64 - 51K, 1/8W

R66 - 10K, 1/8W

R69 - 110 ohm, 1/4W

R70 - 1K, 1/8 W

BR10 - a simple jumper or "bridge"

BR3 - Jason listed this as being present in his PS9, it wasn't present in mine.

D17 - simple diode, 1N1004 or equivalent.

D26 - it's a zener diode, previous forum discussion reveals it should be approx. 68v.