My cars been driving wierd for a while now and I drove to the local dealer to get it checked out. He didn't find any codes, but he looked at a diagnostic reading. Suposedly if that reading is below 95 the MAF is bad. Mine was at 85. I switched out the MAF with my father's Infiniti to troubleshoot that. I still had the problem. I figured since it wasn't the MAF itself it might be connected to it, so I was going to check the voltage to the MAF. I can't find what it's supposed to be though.

 

It's throwing P0113, P0123, and P0223. I know it's TPS and IAT.

 

Can rule out the MAF and throttle body. I swapped them with the ones from my father's G and it's still doing the same thing.

 

You switched the TB also and plugged into the TPS ? Just wanted to verify.

 

The TPS is on the side of the TB, right? I thought it was, but on a site it said the VQ had two TPS. Anyway, I did plug in the connector on the TB.

 

From what I keep hearing from you guys, Nissan stealerships do diddley squat
for most of us! I guess finding a nearby mechanic with diagnostics equipment
is the way to go. Then, again, it's h-a-r-d finding an honest mechanic (???).
Politicians, lawyers, mechanics...I dunno, man, I dunno...

 

I also checked the voltage on terminal 1 of the throttle control earlier and got 5.11, when it's supposed to be approximately 5. I just checked the continuity from terminal 5 to engine ground as said by manual and got around 13.5 ohms. Is that good? They didn't give a number in the manual.

The big thing is terminal 69 (TPS 2), as indicated by the CEL codes. It's reading over 12v when it's supposed to be under 4.75. In the manual it says if no go on that to replace the throttle control actuator. I already did that, when I switched the throttle body, right?

Also I'm confused as to where the TPS are anyway? It looks like the manual was showing the TPS being in the throttle actuator, but I thought they were seperate.

 

I used to work at a dealer and still have ties there. I still try to do my own work if I can, as they still charge $72/hour.

 

The throttle body contains both the throttle control actuator and throttle position sensor. So yes when you swapped the throttle body with the known good throttle body from your dad's G, you also swapped the previous mentioned components. By the way there is only one throttle body on your Z so there is only one TPS. The TPS contains two sensors one to measure the speed of the throttle valve opening/closing and another sensor to measure the actual position of the sensor. Is that what is confusing you and making you think the Z has two TPS sensors? Plus all your codes point to an open circuit in the TPS/APPS (Accelerator Pedal Position Sensor) wiring harness or connectors.

 

Also 03Zilverstone did you perform the Throttle Valve Closed Position Learning and Idle Air Volume Learning procedures? Both must be performed everytime the throttle control actuator is disconnected or replaced. If not you may have actually solved your problem, but the car wasn't able to fully recognize the good throttle control actuator from your dad's G.

 

I did those. I was going by the service manual on the sensors. And I think I may have found the problem. It would explain why I was getting too much power to the IAT and TSP, right?

https://my350z.com/forum/engine-and-drivetrain/352941-ecu-compatability.html

 

gas pedal is bad

 

???

Not questioning you. Just asking what your reasoning is, since to me it would point to a short were the water got to the connector at the ecu.

 

did you check what the codes meant at the other site?

 

What do you mean? I checked the manual that came with my OBD-II reader and my 350Z service manual.

 

That's w-e-i-r-d.

 

Anybody?

 

Just last weekend at VIR had the same

PO123 and PO223 codes

Description of vehicle obd trouble code P0123 - Throttle Position Sensor/Switch A Circuit High Input.

P0223 - Throttle Position (TP2) Sensor Circuit High Input

Called my shop foreman buddy - ASE Nissan tech, he says change the gas pedal so I did. Once the pedal was off we did check for power at the plug and if I remember right the manual says approximately 5v at pin 6. We had approximately 5.2v so we replaced the pedal assembly. Cleared code, problem solved.

 

Did you just have to switch the sensor with the torque bolts? I only remember seeing that one.

 

no you can't replace the sensor, you have to order the pedal assembly. only about 3-4 bolts holding the pedal in, shouldn't take 10 minutes for the whole swap.