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Another What plug thread

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1012011757a.jpg

 

99 Forester 5MT. Not mine, friend just sent me this picture.

I think my 99 OBW has the same plug sitting up near the top of the firewall, just below the wipers. I don't know what it is for, I have never used mine.

Recent work done? Check engine light on? Some reason to suspect it actually plugs into something? A lot of car makers seem to like leaving test connectors all over the engine bay and under the dash with no apparent destination.

In the area of O2 sensor connector.

 

Never worked much on Forester's though.

 

On Legacy's the O2 connector is often white.

O2 connector would also have 4 wires wouldn't it? At least 3 anyway.

How many wires does the speed sensor have? It's somewhere on that side of the transmission isn't it? (having a major brain-fart day :-p )

its actually my forester, thanks for starting a thread...

 

its a 2 wire plug, one black and one white with black stripe.

i have the codes P0500, P1540 and P1507

 

its the only plug i can find under the hood that isn't being used. Previous owner had the HG's done, timing belt and valve job back in Feb.

  • Author

Could this be the source of the speed sensor cel?

Aha! P0500 speed sensor A malfunction

P1540 Speed sensor malfunction ( long term diagnosis)

P1507 Idle control malfunction ( fail safe mode)

 

On the p@ssenger side of the transmission case about 12-15 inches back from the bellhousing, up at the top there is a recess in the side of the case with a cylinder sticking out of it at a slight angle. It should have a couple wires sticking out of the top that should be routed towards the front of the transmission. More than likely someone unplugged it and dropped the connector so now it's hanging down by the front cv joint on that side. Worst case it fell and landed on the catalytic converter and has been melted/burned beyond use.

 

The Idle control malfunction will probably go away when the speed sensor issue gets fixed.

Aha! P0500 speed sensor A malfunction

P1540 Speed sensor malfunction ( long term diagnosis)

P1507 Idle control malfunction ( fail safe mode)

 

On the p@ssenger side of the transmission case about 12-15 inches back from the bellhousing, up at the top there is a recess in the side of the case with a cylinder sticking out of it at a slight angle. It should have a couple wires sticking out of the top that should be routed towards the front of the transmission. More than likely someone unplugged it and dropped the connector so now it's hanging down by the front cv joint on that side. Worst case it fell and landed on the catalytic converter and has been melted/burned beyond use.

 

The Idle control malfunction will probably go away when the speed sensor issue gets fixed.

 

i know what i'll be doing when i get off work tomorrow.

 

thanks guys!

i couldn't find anything dangling anywhere on the passenger side...i'm sure i saw that little cylinder but the plug on it was plugged in to another and couldn't reach the mystery plug

Hmm. Well double check the connection in the speed sensor plug, just make sure it's clean (no dirt/grease) and the pins are straight.

 

Your problem may be elsewhere. If the speed sensor is unplugged the speedometer won't work, so if the speedo works the sensor wiring isn't an issue.

Good pic of the location of the speed sensor on a manual trans. Stole it from Gloyales transmission seal thread in the USRM.

Right smack in the middle of this pic with the wire pigtail pointing towards the bottom of the pic.

DSCF0035.jpg

i think this puts the mystery plug to rest...

 

the 2 plugs on top of the tranny are plugged in by the mystery plug, while the speed sensor is a little farther down.

 

could it be wiring or just a bad speed sensor all together with the 2 codes being thrown for it...

 

i was driving it a little earlier and seemed like under a little harder acceleration the CEL was flashing, haven't seen that before with it.

 

would ask if the IACV code could cause this mess but i wouldn't figure that to cause the no speedo.

 

checked out the pins on the VSS yesterday and they looked straight and clean, no debris, heard in snap in.

 

sorry still a newb at these things

sorry still a newb at these things

 

No need to apologize! Trying to help you solve the problem helps us all. (That's what's so great about this place!) :burnout:

i was driving it a little earlier and seemed like under a little harder acceleration the CEL was flashing, haven't seen that before with it.

This means the ECU is detecting a misfire.

 

would ask if the IACV code could cause this mess but I wouldn't figure that to cause the no speedo.

If the speedometer does not work there is a problem between the sensor and speedometer. Either the wiring is messed up, or the sensor is dead, or something.

 

The speed sensor is plugged into some part of the wire harness, what color are the wires on the harness it's plugged into?

They should be one black and one black with white stripe IIRC. Or it might be one black one white.

What color are the wires on the mystery plug?

the mystery plug is in the harness by where the 2 pigtails in the top of the picture plug in at. the 2 colors of wire for the mystery plug is a solid black and a white with black stripe...

 

i'm thinking the vss are a 2black wire combination, hadn't looked real close but they are both dark colors, not sure if one has a stripe or not. but the vss is plugged into the harness

Right. Both wires on the sensor pigtail are Black.

 

The wires they connect to in the harness are Black and White or some combination of the two colors. One is solid Black IIRC. The other is either solid white or white/ black stripe, I just don't remember exactly which. Of course this is for early second gen Legacy's, it may be different for the Foz/Imp cars.

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