Need to some help from wiring gurus or MIVEC gurus. I have replaced everything in the MIVEC system with donor parts, replaced the oil pan with a new one, and I am still having a MIVEC problem that seems to be low oil pressure and the intake cam rattling inside of the MIVEC sprocket hub when the MIVEC engages.

If I flash the MIVEC map to 0s it goes away, or when I unplug the solenoid it goes away. WTH! I have lost my mind with this problem.

Does anyone know how to test the harness plug for the OCS at the solenoid to make sure this problem isn't a wiring gremlin? What voltage should I expect?

Please help a beat down evom'r.

 

Bump,

Anyone want to find out for me what the voltage range is at their MIVEC plug? Just disconnect the plug at the OCS, the solenoid just left and lower to the MIVEC gear. Put a volt meter to it, run the engine and rev past 4k a few times. You should see some readings as the harness would fire off the solenoid.

Or if you're clever with good metering tools you can identify the voltage from the back of the plug while its running and plugged in.

Help!

 

This is the circuit diagram in the FSM, but I can't find what values I should be testing for. Anyone?

 

You should have a constant 12v on pin 1 at the solenoid when the solenoid is energized, you measure this to a good gnd. On pin 1 will be a PWM signal, you will most likely have to have a meter that reads pwm signal to test it. Best way is just to load test the wire from pin 2 to pin 32 at the ecu.

It sounds like you have an oiling problem though, did this problem start out of the blue?

 

*also, unplug the ecm connectors and check continuity (ohms) from pin 2 at the solenoid to a good ground and make sure you have an open circuit (greater than 1k ohms).

 

OK,

I tested everything in the FSM, which gave:

At the ecu pin 32 has battery voltage
At pin 2 at OCS I have battery voltage
At pin 2 I do not close a circuit to ground, your last comment.
I checked the relay and one just like it and they are identical and seem fine.

I wanted to check continuity from the relay pin 4 to the harness OCS pin 1, and things got weird.

That connection always grounded out ( completed a circuit to neg battery). I wasn't expecting that. I figured the relay would connect that ground, but the relay was unplugged. ? what would the relay do if pin 4 is grounded even without the relay plugged in. This is where electronics turns into voodoo for me.

I undid a bunch of the harness and found that "junction box" comment meant that pin 4 connects with a giant crimp of about 10 other wires, all of them red yellow. Yay.

Still those all go to negative even with the relay unplugged. Could that be logical or does that mean the harness is grounding somewhere it shouldn't?

I worked on the oiling problem angle for 4 weeks. Replaced the entire mivec system, and a new oil pan. No change. It could still be that but I switched to electronics troubleshooting.

yes started all of a sudden. I replaced the prints in the tcase and trans connection and regasketed the oil pan, and then when I started it I had this noise.

Thanks for any help!!!

This is some history on the noise and oiling avenue....
https://www.evolutionm.net/forums/ev...-new-post.html

some attempts at the mivec and history
https://www.evolutionm.net/forums/ev...ere-start.html

 

I beilieve the way it works is that you get power(12v) from the relay, and the ecm cycles the gnd on pin 2. But this is only when the ecm is activating the solenoid.
The ecu sends out 12v on the gnd circuit (pin2) when the solenoid is not being activated.
With the solenoid and relay unplugged, if you have a short to gnd on pin 2 at the solenoid then you have a pinched/rubbed through wire. Or something else that is connected to that joint connector is shorting to gnd.

 

Have you hooked up an oil psi gauge yet to verify you are getting sufficient oil pressure? Reading your other posts it really doesn't seem like a wiring problem, 99% of the time there's a problem after working on a vehicle, it was caused by something that was done, directly or indirectly. Being that you had the oil pan off, I would be willing to bet its an oiling issue. Is there a chance you cracked the pickup tube when getting the pan on/off? Did you use silicone on the gasket that could possibly have clogged an oiling hole?

 

That is very logical and why I spent time and money on anything I touched during that process, but it all dead ended. I decided to buy a new oil pan thinking I may have slightly changed its shape, but that didn't help. Yes I used the RTV that you have to for the gasket process ( there is no actual gasket). I completely agree with this statement and why it's so frustrating that it would be totally ironic and unrelated.

3 years ago I had a similar issue that required the same fix. The O2 wire, in the same loom became inexplicably grounded from what I could tell. It took me forever to figure it out, and when I jumped it directly from the ecu it resolved. I could never find the break. That would be my supporting argument for wiring issue.

I know for certain that when I have the solenoid unplugged and the relay out that stretch of wire that includes the joint completes to ground. Do you agree that this is enough to warrant taking the harness out? From an electronics standpoint this should not go to ground , correct? I can video it later today to confirm.

 

When you say you have a gnd, what is the reading? the problem could be that you have a gnd on another circuit that is also hooked to the joint connector.

IDK what that joint connector actually looks like but if you can unplug it, check for a gnd again on pin 1 (at solenoid) with the joint connector unplugged. If you still have a gnd then you have a short in the wire from the solenoid to the joint connector.

 

Just looked at the wiring diagram to see what else is on that joint connector and there is no way you can have a short to gnd on that wire, that wire is also the power for the injectors and multiple other sensors so if you had a short to gnd you would blow the fuse and the car wouldn't even run.

You are probably reading a ground because of the other circuits on that joint connector. ie: through the injectors.

 

Lets start over. Plug everything back in and disconnect the Oil control Solenoid, Turn key on. You should have 12v at pin 2. If so, then the relay and that wire are good to the solenoid. You have already checked the wire from ecm to solenoid which tested good as well.

So either you have an oiling problem or the ecu is activating the solenoid incorrectly (tune or bad ecu).

 

OK, I have completed those tests again, and everything is as it should be. I created a set of videos in case by some weird chance it help someone else troubleshoot. I guess now I have to try and go back to figure out what could be causing what I assume is low oil pressure at the solenoid.

Everything goes to ground:
http://www.youtube.com/watch?v=JPpqI...ature=youtu.be

Key On at solenoid:
http://www.youtube.com/watch?v=zuJY0...ature=youtu.be

Key Off at solenoid:
http://www.youtube.com/watch?v=lYjh4...ature=youtu.be

 

I would definitely get an oil pressure gauge on there somehow, idk if there is a way to check it at the solenoid but at least check base oil pressure and make sure it is sufficient for mivec operation.

 

I ordered a prosport digital to get a quick and inexpensive way to measure something. I may opt for a more sophisticated solution later to route into the ECU to log with EvoScan, but I need something fast so hopefully I can get that up and running by this weekend. I don't know if there will be a way to connect near the solenoid. Maybe some way at the feed location at the bottom of the block to at least confirm the channel in the block is getting good oil pressure.