autocrash

So.... I'm testing my pressure sensor when I notice that the check engine light is now flashing a 30 as well.
I test the split air solenoid for continuity and get that.. my question is what is the purpose of the two wires going in? and are they BOTH supposed to read +12V? also, what would cause the voltage to NOT drop in 5th gear (it's supposed to drop to 2.5V)

I know my pressure sensor is bad and needs to be replaced, would this be affecting it?

Also, what is the purpose of the solenoid? I know it directs air to the main catalytic convertor, but under what conditions?

Thanks in advance for any help!

NZConvertible

The black/white wire is constant 12V from the main relay, the white wire is switched earth from the ECU.Some air flows to the cat via the split air pipe under most conditions, but this solenoid opens in 5th gear to increase the amount flowing. Hailers is the Secondary Air Injection expert around here, I'm sure he can expand on this and answer the rest of your questions.

BTW, is it just me or are pages F2-60 to F2-69 missing from the online 89 FSM?

autocrash

uhmm.. my wires are black/white and black/blue.... so does this mean that the black/white is still 12V constant?

The one on FC3S.org has them... I think....
...maybe I should look again.....

NZConvertible

OK, I’m basing this on the 88 FSM, since both the split air solenoid section and the wiring diagrams aren’t in my 89 FSM. But I misread the diagram slightly, in a S4 the other wire is white at the solenoid, then changes to black with a blue stripe (B/L) at the harness plug. I guess in the S5 it’ss B/L all the way. The wiring diagrams show the B/W wire providing 12V to the split air solenoid (and most of the other emissions solenoids), and the B/L wire going to the ECU. The split air solenoid section says the B/W wire is the one that should change voltage, which seems to contradict the wiring diagram. I’m not 100% sure. Hailers, where are you?!

HAILERS

Sink or Swim NZ! Hee, hee, chuckle, chuckle. Everything NZ said is right. The only problem is the 88 fsm says its a white wire. My 87 I THINK, is black/blue. I'm at work and can't check. So til then, theres 12v constant on the black/white wire and you'll also see 12volts on the black /blue wire because your reading thru the coil on the solenoid.

The ECU will put a ground on the black/blue wire only when in fifth gear. Then both wires will drop down to about 2volts give or take one. Called a voltage drop. Put your meter in the back of the connector, either wire with the key on. Then chunk the gear lever into fifth. Walla voltage drop from 12 to approx 2volts.

Has squat to do with the pressure sensor.

By the way, yesterday on my turbo, I pulled the vac line that feeds the switching diaphram in the acv. Then checked to be sure there was flow from the split air pipe. It was anemic. Sooooooo I put the split air pipe in some water and watched it make bubbles. Took the black/blue wire out of the connector on the split air solenoid, and left the black/white on the solenoid. Put a ground on the place the black/blue went. It made more bubbles than before. I might make that same arrangement when I go for emissions testin next month. I'm a worry wart. Got a new cat and pre-cat, all emissions work and I still worry.Got a new emission standard for Texas this year. Six Rotors is THE emissions guru.

I'll double check the wire colors when I get a chance. Might go to the parking lot and take a look during lunch. I think its a typo in the fsm. Do the fifth gear check as described above to make sure all is well as is.

HAILERS

My 87 n/a outside at work seems to be blue/black for what its worth. Doubt theres a real problem in that area.

Those pages seem to be there online....60 - 69. You seem to have the *OVERSEAS VERSION* of the manual. humor.

Ooops. Sorry I did not really read your post. Why would the voltage not drop. Easy. The over the top switch is not working. See page 50-25 of the wiring diagrams. The over the top sw is located on the transmission. I THINK on the left side. Don't hold me to that please. Should have two wires. One black and the other Black/blue. All it does is put a ground on pin 1I and the split air solenoid when transfering to fifth gear. Check the connectors near the over the top switch for being on good.

autocrash

Hailers, man, NZconvertible was right: You are the secondary air injection god

Thanks all! (hope I can fix this soon... I want to DRIVE!! )

NZConvertible

Ha ha, very funny...
I downloaded it from www.fc3s.org the day it was uploaded. I've just downloaded it again and the pages have magically appeared! Must have downloaded a "beta" version...