My vanos is stuck on

[JGood]

I checked for continuity between pin 7 on the harness at the DME (that's the vanos wire) and chassis ground, didn't see it. But plugging into the other pins on the harness plug and checking for continuity to pin 7 caused my multimeter to beep intermittently on at least 2 of the other pins. It was beeping intermittently, approximately once per second, as opposed to one long beep for the duration of the time that the leads are touching, which I thought was strange. An example was pin 2, which is for the ICV 'close control'. It registered as 36 ohms resistance (or maybe it was 36k, I forget). Either way, why would they be connected in any way? Oddly enough, the diagrams I have posted above also show pin 2, to the ICV. Maybe they got pinched together and are contacting somewhere in the harness? If that's the case, FML.

[JGood]

If I unplug my solenoid at idle it will stumble and idle like crap, too. That's not because it's engaging the VANOS when it's not supposed to, but because the ECU checks the solenoid when it starts. It needs to see that load.

Only way around that is to put a 100Ohm power resistor in there to satisfy the ECU.


Edit: Re-read and you never said it stumbles at idle. Never mind! Checking for +12v at the harness with the multimeter like you mentioned will work.

Mine does stumble at idle if I start the car with vanos unplugged, then plug it in.

I just now took it for a drive with the vanos plugged in. There's no question about it, the vanos is stuck on with the solenoid plugged in. Mid range is great and it does not pull for shit up top. I'm 110% sure. I drove it to work today unplugged, and it was so dead in the middle, and pulled so much harder up top. I really don't need to see voltage to verify it.

[hoveringuy]

I checked for continuity between pin 7 on the harness at the DME (that's the vanos wire) and chassis ground, didn't see it. But plugging into the other pins on the harness plug and checking for continuity to pin 7 caused my multimeter to beep intermittently on at least 2 of the other pins. It was beeping intermittently, approximately once per second, as opposed to one long beep for the duration of the time that the leads are touching, which I thought was strange. An example was pin 2, which is for the ICV 'close control'. It registered as 36 ohms resistance (or maybe it was 36k, I forget). Either way, why would they be connected in any way? Oddly enough, the diagrams I have posted above also show pin 2, to the ICV. Maybe they got pinched together and are contacting somewhere in the harness? If that's the case, FML.

I wouldn't put too much stock in continuity readings between those pins. Is pin 7 grounded so that it lights a 12v LED? All of those pins run through a MOSFET array which is how the ECU chip controls switching power.

[JGood]

All of those pins run through a MOSFET array which is how the ECU chip controls switching power.

Ehh, not without the DME. I unplugged the DME, then tested continuity through the harness plug that the DME plugs into. So there should be no continuity to that one wire, it should run straight to the solenoid plug without touching anything else.

[hoveringuy]

Ehh, not without the DME. I unplugged the DME, then tested continuity through the harness plug that the DME plugs into. So there should be no continuity to that one wire, it should run straight to the solenoid plug without touching anything else.

True dat.

[JGood]

Just read my owners manual for the meter. It says it will beep if the resistance is less then 35 ohms, and will not beep if it is over.

So my was beeping intermittently, and read 36 ohms when I looked at it. That seems strange. Maybe it's right on the border? I'd think if the wire was shorting, it would be either full continuity or no continuity.

This is so frustrating...

[nando]

the case shouldn't get so hot that you can't touch it. Shouldn't matter if it's touching the car or not.

could the vanos unit be faulty? as you've discovered, it always gets 12v, and the ECU simply grounds it to turn it on. maybe the vanos unit itself is shorting out.

[JGood]

the case shouldn't get so hot that you can't touch it. Shouldn't matter if it's touching the car or not.

could the vanos unit be faulty? as you've discovered, it always gets 12v, and the ECU simply grounds it to turn it on. maybe the vanos unit itself is shorting out.

I'm checking for ground with the car running and the vanos solenoid unplugged (I'm actually checking for ground from the vanos plug on the wire harness). So I'm putting my positive and negative multimeter probes on both pins in that connector, and it's getting 12v at all times. So the solenoid has no interaction, it's unplugged.

Very good idea though, I never would have even thought of that.


I grounded my case very well, it made no change.
I found the pin 7 wire behind the DME plug, and pulled it until the connetor at the solenoid started puling back through the harness. I did the same thing with the positive wire. Both moved independently of all of the other wires. This proves the wires aren't cut or smashed or melted together or anything like that, so the harness should be good.


I'm getting a known good 506 DME, putting my chip in it, and trying it in my car tonight.


I always get the weird problems. Huge thanks to Matt / TRM. He's been helping me via PM's basically parallel to this thread, and even sent me a custom chip to try.

[nando]

I have a vanos plug and full length of wire if the harness turned out to be bad. You'll have to splice it in, but the M50 harness makes that pretty easy.

[JGood]

Oh, and I believe me getting 36 ohms resistance between pin 7 (vanos) and pin 2 (ICV) is due to the fact that both of those components were plugged in, and share the same positive connection. So the current from the multimeter was traveling through the ground of the vanos, to the positive, which meets at a positive junction with the ICV, then through the ICV negative back to pin 2. So it saw a connection, but had the 36 ohms resistance caused by the solenoid and ICV. That's my guess. I'll unplug the vanos solenoid and retest, to verify.

[JGood]

I have a vanos plug and full length of wire if the harness turned out to be bad. You'll have to splice it in, but the M50 harness makes that pretty easy.

Awesome! Actually, having that would make even just testing things 10x easier. If this DME doesn't work tonight, I'll be in touch. Thanks.

[JGood]

LED's don't lie?

I mounted a 12v LED on my steering column, and spliced it into the + and - wires of the vanos harness connector, up closer to the ECU. With the vanos plugged in, I drove around. It lit up exactly when it should... only after moderate thottle load, between idle and 5200 RPM's. At light throttle load, or above 5200, it never lit. So my vanos is fully functional.

Weird thing is, I then hooked my multimeter up to the LED, and drove around. It read 12-14v at all times, except for a split second every time the LED turned on or off, it dropped to zero. Can any of you EE's explain that? haha

I guess when I disconnected the vanos, it just made the top end feel so much more powerful, since the bottom end was so dead. I guess my butt dyno needs calibrated.

[nando]

LED's don't lie?

I mounted a 12v LED on my steering column, and spliced it into the + and - wires of the vanos harness connector, up closer to the ECU. With the vanos plugged in, I drove around. It lit up exactly when it should... only after moderate thottle load, between idle and 5200 RPM's. At light throttle load, or above 5200, it never lit. So my vanos is fully functional.

Weird thing is, I then hooked my multimeter up to the LED, and drove around. It read 12-14v at all times, except for a split second every time the LED turned on or off, it dropped to zero. Can any of you EE's explain that? haha

I think it's a PWM signal, at least the ETM diagram suggests as much. the DMM won't really be fast enough to read the signal though.

[JGood]

Interesting. Why would they use a PWM signal? I'd think you'd want constant on or constant off to the solenoid (which uses on or off to allow oil pressure to pass through vanos or not pass through).

[nando]

at a certain duty cycle, the solenoid would be on/off anyway. I don't know, I was told the evaporative purge valve was PWM and I had thought it was simply on/off too.