We recently finished installing a Procharger Kit on our 2006 350Z
The car is imported from USA so it is a US-Spec Car...

We also installed an AEM Infinity 10-12 with 350Z PnP Harness

Everything is fine, we can drive the car without any problems. The only problem is we lost Power Steering. If we install the OEM ECU back on the car, the Power Steering comes back on.

I talked to AEM Tech Support, they couldn't fix the issue as they say the Infinity does not have to do anything with Power Steering. I checked the 5V output from the ECU and I do see the 5V output coming out from the Infinity ECU

Well, it's either the ECU or the Harness cause the it works when we install the OEM ECU. What can cause the Power Steering to not work?

Right next to the ECU there is a connector for Power Steering. I want to check all the wiring with that but I couldn't find any Wiring Diagram for the Power Steering Connector

Any help would be greatly appreciated...

 

I wasn't aware the power steering had any electrical interface to the ecu besides the one pressure sensor that's at the high pressure output of the power steering pump that monitors the system pressure. As far as I know it helps prevent engine bogging/stall when using the power steering at low engine rpm. I don't believe the ECU has any way to disable the power steering system as you describe.

Check if you have the correct voltages on the voltage supply wire to the sensor, and the sensor signal back to the ECU. Check at the sensor, and at the ecm. Maybe it is an issue with the jumper harness.

Search power steering in this document. All the terminals and voltages are listed there.
http://www.nicoclub.com/FSM/350Z/coupe/2006/ec.pdf

 

the only thing that would cause the power steering not to work is a cut power steering belt or a bad pump.

Nothing to do with the ECU

 

Yeah that's what I was thinking.. It's a completely mechanical system. The only electrical is the one sensor that is monitoring only.

 

I know this is an old topic but I'm reviving it so there aren't multiple threads on the same topic.

I've had the Infinity for while and I've noticed a similar issue where the power steering seems to be stiffer/harder than when you have the OEM ECU, and I've confirmed it through testing. While I can't say that that the power steering is totally not functioning (because it is functioning and helping to certain degree) with the Infinity, its definitely not assisting as well as with the OEM ECU, particularly noticeable at low speed.

I've decided to live with it, but I was looking through the FSM recently and I think the power steering system is not an on/off thing per see; its assist can vary by speed via the Power Steering Control Unit. (See Steering Control Unit (STC) in the FSM for details...for reference my car is a 2006 Enthusiast); they call it the Electronically Controlled Power Steering System in the FSM.

Looking at the diagnostics for the Electronically Controlled Power Steering System (see pic below) it seems to show the assist varying depending on the speed of the vehicle, so what I'm thinking is that the Infinity for some reason or another is not adjusting to the speed of the car and is just providing a set amount of power steering support (which I'm thinking is set to a higher vehicle speed, as logically you probably want less steering help at a higher speed).

Does my logic make sense? Other Infinity guys chime in...