Potential causes of a P0412-need help

[My_Silver_SHO]

Potential causes of a P0412 code include:

1. Short to ground on control circuit
2. Short to voltage on control circuit
3. Control circuit open due to damage, etc.
4. Open or short on battery feed circuit to solenoid
5. Open or short on battery feed to relay control circuit


Where to start? I am better with mechanical than electrical issues.

 

[SHOZ123]

It's usually the relay.

 

[My_Silver_SHO]

It's usually the relay.

I now have 3 solid state relays, i have tried all 3.

I think I may pinched a wire while doing the engine swap. Just don't know which.

Could there be a pin difference that control the SAI in the connector above the trans?

 

[SHOZ123]

Did you change the wire harness?

 

[SHOZ123]

Have you hot wired the pump to see if it runs?

 

[SHOZ123]

As far as wires go

White appears to be 12V+ from the battery to the relay for power.

Brown appears to be a ground from the PCM to the relay and also grounds the SAI bypass solenoid. This solenoid is wired hot off the White wire all the time. So the ground signal would be coming from the PCM to the relay.

White/Orange is power from the relay to the SAI pump and then to the PCM as a signal the pump is getting power.

Black is ground for the pump.

 

[My_Silver_SHO]

Have you hot wired the pump to see if it runs?

Yep, pump turns when hot wired.

 

[My_Silver_SHO]

Did you change the wire harness?

Yep. 97' harness . 96 computer(JJK2)

 

[My_Silver_SHO]

Still bugs me that the Custom Tune I bought did not eliminate the SAI.

 

[My_Silver_SHO]

As far as wires go

White appears to be 12V+ from the battery to the relay for power.

Brown appears to be a ground from the PCM to the relay and also grounds the SAI bypass solenoid. This solenoid is wired hot off the White wire all the time. So the ground signal would be coming from the PCM to the relay.

White/Orange is power from the relay to the SAI pump and then to the PCM as a signal the pump is getting power.

Black is ground for the pump.

Thanks again Paul! The WHITE power was the issue. I ran another power source and it works perfect!