[SOLVED] MS6 PCM Not sending ground to OCVOCV

Hello guys, I need your help, my 2007 MS6 have p0012, the PCM is not sending ground signal to the OCV, if I manually add ground to the valve the VVT moves. Is there any ground related to the OCV? Anyone know if the ECU from mazdaspeed 3 is compatible with mazdaspeed 6?

 

Also I test the voltage from the OCV connector and the two cables have 12v, it is not supposed to one be positive and the other one negative?

 

It sounds like you have a short between the wires or a short to voltage. You should check continuity between the OCV and the ECM wires and then load test each wire to make sure there isn't high resistance somewhere.

Remember that one strand of wire can be good and show low resistance which is why load testing the wire to make sure it can carry a load is important.

 

I will do that. I just test for continuity between OCV connector (both pins) and both of them lands on the same pin of ecu connector. I don't understand whats going on here.

 

With the OCV connector disconnected...
One pin should have 12V and have continuity with the fuse ENG BAR 15A. (Test continuity with fuse removed)
The other pin should have continuity with the PCM pin 4S.

If you need some help with electrical diagnosing, <<THIS>> thread would be good.

It would be valuable for you to consult a wiring diagram. The info you need to consult is on pg#s 0140-3a, 3g & 3h of the Mazda MS6 wiring diagram. If you invest a donation <<HERE>> you will have free access to wiring diagrams, workshop manuals plus Tech & Sales training literature. Worth the investment the first time you use it!!

 

Lucky me I found those pages on a forum, I test one pin that have 12v with a test light ( it turns bright) has enough amperage to move a solenoid. If I measure the same 12v cable from the OCV connector connected to OCV the voltage drops a lot, the test light shine so dim. I got continuity with ENG BAR 15A fuse disconected and continuity with PCM pin 4S and others. I'm lost, maybe my ECU no bueno.

 

Also I ran a cable from ECU pin 4s to the OCV connector negative pin and nothing...

 

Is this a new OCV?
Are you testing for continuity with components disconnected or connected? (OCV & PCM)
Do you have 12V to both pins at the OCV connector with the PCM disconnected?
Did you read the thread @L337TurboZ wrote about electrical diagnostics? I think you should read his thread.
Did you <<LOAD TEST>> both wires.
The test light diming could be the circuit is incapable of carrying the required current, as well as the load requiring more than the circuit can supply. The wiring needs to be vetted first. Then the OCV can be scrutinized and the PCM should be your last kick at the can.

 

I bought another MS6 ECU, i'm gonna report results when swapped and programmed.

 

*SOLVED, it was a faulty ECU, now the car pulls hard, indeed, it was a combination of problems (Bad ECU, oil leak to VVT gear)

 

Glad you got it sorted