How To Service a VQ35 Throttle Control

How To Service a VQ35 Throttle Control

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We love the flexibility and robust nature of the 3.5 liter Nissan V6 that helped redefine the six cylinder performance market, and it’s still going strong. It’s certainly one of the best engines available when it comes to bolt on performance, with a strong following of aftermarket parts.

The one thing we don’t like about the VQ35, or any vehicle for that matter is the drive by wire. The throttle control is an electronic servo system that replaces the drive by cable design we’ve all come to love and modify. This throttle control can often be called the throttle position sensor, TPS, Drive by Wire, DBW or electronic throttle.

Today we’ll be showing you how to complete service the throttle control in your VQ35 in our How To Service a VQ35 Throttle Control. We’ll be showing you how to service, program and replace your throttle control in your 3.5 liter Nissan V6. The Nissan part number for this unit is 16119-8J10C, and there are several components to the throttle control in your Nissan 350Z or Infiniti G35.

To begin, you’ll need to secure the vehicle safely and remove the VQ35 mass air flow sensor (MAF) and intake snorkel. If you need instructions on how to do that, check out our How To Test VQ35 MAF Guide. Because the throttle control unit on the VQ35DE is located in the far back of the engine bay, testing the pins on the throttle control unit can be problematic because of the lack of space.

We’ll be removing the throttle control unit (TCU) before giving you a step by step guide on How To Service a VQ35 Throttle Control.

Once you have the intake system and tubing removed, you can now see the throttle body as well as the throttle control unit or throttle body.

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Before you begin checking out your Throttle Control Unit (TCU) make sure the throttle blade opens and closes smoothly and without any problems.

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The next step in our How To Service a VQ35 Throttle Control article, you’ll be removing the 4 bolts that secure the throttle body to the intake manifold. But before doing that, let’s disconnect the vacuum lines on the throttle body.

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Leave these vacuum hoses disconnected and move onto the loosening the hex bolts that hold the throttle body in place.

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Loosen the top two bolts and then move onto the lower bolts before removing your throttle control unit.

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With the throttle control unit removed, check your throttle body gasket for any damage or leaks.

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Now that you have the throttle control unit removed, you can take your multimeter and test the unit for resistance. Because we’ll be testing the throttle control unit first, please refer to our VQ35 throttle body wiring diagram located below.

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Now take your multimeter out and you’ll be testing the resistance between PIN 1 and PIN 4.  The resistance here between these two pins should be 1-15 Ω at room temperature. If your throttle control unit does not measure out to that, your throttle body is bad and must be replaced.

Next up in our How To Service a VQ35 Throttle Control Guide, you’ll be checking the HARNESS side of your throttle position sensor.

How to Check for VQ35 Throttle Continuity


 

To check the continuity of the wiring between your throttle control motor and the VQ35 ECU, you will need to locate and disconnect the ECU harness. Remove the key from your ignition or if you have the Nissan VATS or Keyless system make sure your ignition switch is set to “OFF”

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You will be checking for continuity on the VQ35DE throttle control unit harness, so please refer to the throttle control unit harness wiring diagram above. You will be measuring to see if there is continuity from the

Using your multimeter measure the continuity between the pins on the throttle control motor harness and the VQ35 ECU wiring pinout shown below.

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The VQ35DE ECU wiring pinout for throttle control is as follows :

  1. Terminal 3 – Throttle Control Motor Relay Power Supply – Voltage 11-14V
  2. Terminal 4 – Throttle Control Motor – Close – Waveform 0-14V
  3. Terminal 5 – Throttle Control Motor – Open – Waveform 0-14V
  4. Terminal 104 – BLACK – Throttle Control Motor Relay

Now refer back to the VQ35DE throttle control unit wiring diagram shown above, you will be checking for continuity between these pairs of pins. Remember you are checking the HARNESS side of the throttle control unit and the VQ35DE ECU. Do not force or push the test leads into the ECU harness, as you can do serious damage to the metal clips inside. This kind of damage can compromise your ECU’s ability to control and operate your engine efficiently.

You will be checking for continuity between the electronic throttle control actuator terminal 3 and checking ECU terminal 4. With the key out, ignition set to “OFF” you should see continuity here at these two pins. Now check the same pin 3 on the electronic throttle control actuator and measure continuity to ECU terminal 5. There should NOT be continuity between the electronic throttle control actuator terminal 3 and ECU terminal 5 with the engine off.

Next on our How To Service a VQ35 Throttle Control Guide, you’ll be checking throttle control actuator terminal 6 and measuring for continuity at ECU pin 5, there should be continuity here. Using the same throttle control actuator pin 6, now measure at the ECU terminal 4, and there should be no continuity here.

Checking the VQ35 Throttle Control for Power


 

To see if your VQ35 throttle is receiving power, measure PIN 1 on the engine harness for a switched power signal. You will need to put your ignition switch to the “ON” position to test this terminal

You have now completed our How To Service a VQ35 Throttle Control Guide, if you find your throttle control actuator is bad replace it as well as the gasket. You will need to reprogram your electronic throttle control in two steps, which we will be outlining in our How To Series for the VQ35DE.

Have any questions or comments regarding our How To? Leave us a message below!

IPC OBDII Trouble Codes
Next – Program your VQ35 Throttle Control

3 COMMENTS

  1. grt source, thanks for doing this..
    I have a 03′ G35 (VQ35) that went into LIMP mode with codes for TB and APS. Replaced the TB, the accelerator pedal sensor but couldnt get the CEL to blink during the relearn, gave up and took it to dealer for relearn.
    Am being told they did it and it didnt help – they are sensing a low voltage between APS and ECM which signifies a short which will require 6 hours of diagnosis – in other words they charged me $120 to tell me they want me to spend $900 to then tell me what could possibly be wrong.

    Is there any other way?

    • Hi Mike, thanks for commenting.

      Have you tried measuring voltage at the harness itself? This could show you what the problem is. If they are sure it’s a short, there’s no real fast way for a fix unfortunately. You are looking at wiring up a replacement harness and connector, or replacing your engine harness all together to fix your VQ35 throttle problem.

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