tcb100

What does it do?

DaleClark

iTrader: (55)

Uh, you bigtime need some more information there...

Dale

JaNusSolSumnus

He is talking about the 1-2 switch on the manual trans.

From what I recall... it relates to emissions however to what extent I do not know -- You know how you can start the car in gear and the AWS wont hop up to 3k? That is part of the 1-2 switch functions.

~Kris

b3delta

iTrader: (2)

Any update on this question in the last 13 years? Got the harnesses disassembled, if I can remove more I want to.
Thanks

scotty305

iTrader: (2)

I've seen info somewhere suggesting that the stock ECU will either target different boost pressure, or operate the various boost control and sequential control solenoids differently in lower gears. I think it was one of the various Mazda documents, not the main Factory Service Manual but maybe the technical descriptions doc.

arghx

iTrader: (3)

The SAE paper on the sequential system indicated that the system is operated differently in 1st gear.

scotty305

iTrader: (2)

Every now and then I'm tempted to reinstall a bunch of stock parts and drive my car on the stock ECU again. Also, holy crap arghx how on earth do you have even more posts than DaleClark?

arghx

iTrader: (3)

A couple one liners here, a couple one liners there...

Gen2n3

iTrader: (1)

To the OP,

Refer to the FSM, Pg F-12 for the Component Description of the 1-2 Switch. Additionally, inspection procedures can be found on Pg F-173.

Does this answer your question?

b3delta

iTrader: (2)

I'm looking for more of a "what use is this information" answer. The switch detects if it's in 1st or 2nd. Great, what's the ECU need that input for? Does it change fueling? The emissions crap that someone else mentioned? Etc...
Thanks

scotty305

iTrader: (2)

I found the doc, it's the Service Highlights manual. It suggests the 1-2 switch affects how the ECU operates the sequential turbo solenoids, and the Air Pump relay. There might be additional info in other parts of the doc, it's pretty long and the copy I have is images only so you can't find things quickly using CTRL+F.

EFI relationship chart, F-15

b3delta

iTrader: (2)

Boom, that'll do. Thanks fellas

Gen2n3

iTrader: (1)

Scotty, et al:

The same diagram is also listed in the 94 FSM at Pg F-182. Glad to lend a hand!

cewrx7r1

iTrader: (2)

Years ago for some reason (maybe site ownership) our post counters were reset to 0.
Thus he could have much more.

DaleClark

iTrader: (55)

I think it's actually pretty accurate. I was a little late getting on the forum when it first opened.

Anyhow, the 1-2 switch isn't anything super important on the car. It may have more info in the service highlights book as to how it functions. I can't remember if the PFC does anything with it either.

Dale