ford or nissian guys: 2001 villager

okay, I’ve been fucking with this villager for 2 days now in the shop. I’ve totally lost my ass already so I’m past that, I just want to fix it. It’s been throwing a P1105 for a MAP sensor solenoid circuit failure. Here’s what we know.

IGN on it sends battery voltage to the solenoid and is ground side switched by the pcm. There’s 3 ports on the solenoid. A, B and C. A feeds to the air inlet duct, B goes to the MAP sensor and C is the vacuum source coming from the intake manifold.

When the solenoid is commanded on by the pcm air flows freely from A and B. when the solenoid is circuit is open air flows freely from B and C. The solenoid tested out good. I even took a vacuum tee and gauge, placed it between the solenoid and the sensor and road tested it to make sure the map was seeing what it was supposed to with the solenoid closed (no power).

what I wanna know(nobody in the shop knows) is under what conditions does the PCM command that solenoid on and take a MAP reading from the air duct? The shop doesn’t have any diagnostics that will work with a villager and I can’t actually access the MAP pid.

just to add to the story…

heres what I did. visual inspection > vac lines good. test power to solenoid > good, 12v. disconnect pcm, test ground circuit for short to ground > good, not grounding. test resistance ground circuit from pcm to connector > good, 1 ohm. test solenoid for proper air passage flow > good.

at this point i put a pcm in it. send it off and it’s fine for about a day. comes back, shit now what, same code. I’ve got an intermediate problem. feesable, it is an older car. so I pull the pcm connector back off, this time I pull the ground wire out of the connector and slide it over the pcm pin. fuck, it’s loose, it’ll hardly grip the pcm pin. I dug thru the bin of old connectors and finally found a female pin that would work. wired it in, no codes… YET. I sent it off last time and it didn’t have any codes. i’ve gotta have someone drive the hell out of it on monday. If it comes back again it’s getting a whole new ground wire from the pcm to the solenoid, then if it comes back I’m gonna drive it onto canonsburg damn and light it on fire.

all I’m really looking for here is when is that solenoid powered? that will tell me what I need to do for the pcm to self check that circuit so I can know if I’m really done.

The only thing I can think of is KOEO the pcm powers the solenoid and takes a BARO reading from the intake duct. Then when you start the car the solenoid is de-energized and the MAP reads intake vacuum. it’s the only thing that makes sense to me

well i was right about the operation of the solenoid but that isn’t the problem. apparently the pcm interpreted the MAP readings as a solenoid failure. after a full drive cycle it turned up a P0105, MAP circuit failure. Further testing showed the sig rtn shorted to ground, it’s a shielded wire and I think it must have rubbed thru and is grounding out.

fuck this car, going by the wiring diagram I cut the wire before the short and jumped it right to another signal return near it. well it didn’t like that at all. the book says it’s all spices into one sig rtn wire but it just didn’t work. the book fucking lies

well after all this the fucker left on thurs. wiring in a new sig rtn did not work, we even called the ford hotline and they didn’t know what the hell to do

what fixed it?? the damn part i chased in the beginning. MAP sensor solenoid, which is mainly there for evap testing i found out. after so much electical testing all you can do is throw parts at it.

the solenoid worked perfectly, I checked it’s operation atleast a half a dozen times. It’s operation wasn’t the problem tho. the solenoid itself worked fine, it’s resistance however was too high and the pcm didn’t like that when it checked the circuit. Ford did not specify a resistance for this solenoid therefore there was no way to condemn this thing as long as it operated like it should. bullshit move on their part. thanks ford, now I hate you and nissian