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Discussion Starter · #1 · (Edited)
I am having trouble wiring up my Infiniti Q45 TPS and was wondering if someone could point me in the right direction. Here's what I'm working with and the research I've done so far.

Current setup:
7MGTE motor
Stock ECU with ECUMaster DET3 piggyback
70MM Universal Throttle Body (specifically says will only work with Q45 TPS)
Beck/Arnley Infiniti Q45 TPS from rockauto
Inifinit Q45 TPS Connector from rockauto
Build thread for more info

The stock Q45 TPS set up has two connectors. One on the TPS itself with 3 pins. And a second connector with a six inch harness coming off the throttle body with 3 pins as well. My universal throttle body only has the 3 pin connector on the TPS itself. The stock 7M TPS has 4 pins/wires. So i'm trying to figure out which wire from the TPS goes to the stock 7M harness. I found this nice thread from of how both Q45 TPS connectors wire up to the 7m tps. SO from what I gathered, the TPS itself is represented in the blue circles in the pictures below. They correspond to the black (E2) and green wire (IDL). I don't have the connector with the X in the picture. So that leaves the VTA and VCC wires from the 7M harness that need a home. I believe VTA is power from ECU and VCC is the signal from AFM. The other problem is that I don't have the stock Q45 TPS wires so I can't match up the colors. I had to buy an OEM connector and it just came with three black wire leads. So it's kind of hard to match up the wires to the diagram. I posted another pic of his TB and seems like the blue circle is the one I have.

Also, I found this thread where @figgie posted very simple process by elimination steps. I measured the resistance between the terminals on the Q45 TPS and here's what I found.

Terminals: A, B, C. If you are looking at the TPS sensor itself, tab on top. I labeled them 3,2,1 in the picture because i like to make things extra confusing. BUT that is how the TEWD labels male pin numbers.

TB Open
A-B: 1.53 K-ohm
B-C: 3.917 K-ohm
A-C: 5.24 K-ohm

TB Closed:
A-B: 5.30 K-ohm
B-C: 70 ohm
A-C: 5.24 K-ohm

So from this method,
terminal A must be the signal wire
terminal B must be the signal return
terminal C must be ground

Now, how do these findings translate to connecting the 7M harness TPS wires to the Q45 TPS? I found this thread that talks about which wires connect from the 7m harness. BUT I'm still left with some unknowns.

1. VCC -> ??? 5 volt supply
2. VTA -> A signal wire
3. E2 -> B signal return
4. IDL -> C ground?

Am I just screwed using this TB with a stock ECU or is there a way to make this work? I thought about just getting a stock Q45 TB. But then I'd have to get a new flange welded on the FFIM and go through all that.


Here is the stock 7M TPS wiring


Q45 TPS sensor pins:


45 Posts
Discussion Starter · #3 ·
Did you ever figure this out? I'm getting my build together and discovered this process is actually a surprising pain in the ass.
No sir. I ended going back to the stock TPS. And it still doesn’t quite work right with the universal TB I’m using. the only issue is the IDL signal is flaky. When I’m driving and let off the accelerator coming to a stop it will die sometimes and not go to idle state. And the car doesn’t idle up on cold starts. Not a huge deal just annoying. I think the better option is to go with a stock Q45 TB and TPS. I may do that eventually. I’ve heard other people have the same issues with the universal throttle bodies and they leak under high boost. Unless you have a stand-alone ECU then there are more options because they can usually control any set up.
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