One of the more commonly broken, smashed and destroyed sensors that come on a 2JZ or 1JZ GTE is the Sub Throttle Actuator, or TRAC throttle body. This actuator is used by the 2JZ ECU for traction control purposes and helps control and limit wheelspin by dialing down the throttle blade in front of your actual throttle position sensor.
Looking for the 2JZGTE throttle position sensor repair How To? Check here for that How To Service your 2JZ TPS Walkthrough. Today we’ll be taking a look at the 2JZGTE Sub Throttle Actuator, how to fix this smashed actuator and test the actuator as well as how to bypass the actuator itself.
As you can see our JDM imported 2JZGTE Aristo sub throttle actuator has seen better days. We’ll begin by straightening each one of the smashed pins to line up with our six pin connector for the actuator unit.
You’ll be measuring the resistance between the terminals to test your engine harness. The Supra FSM dictates these pins as B and A pins with matching A- and B- pins. We’ll be renaming them for ease of testing purposes.
You will want the sub throttle position sensor to be at 60 degrees Celsius before you begin testing. You will be measuring these combinations of wires with your multimeter to ensure that the proper resistance exists.
- PIN 1 – PIN 4
- PIN 2 – PIN 4
- PIN 5 – PIN 3
- PIN 6 – PIN 3
Resistance between these four combinations on your actuator must be within the 0.82 – 0.98 range of resistance. Once you have tested the wiring to your sub throttle actuator, you can also elect to remove the sub throttle actuator all together.
Once you have this tested, you can move onto adjusting and tuning your sub throttle actuator and sub throttle position sensor. To begin our How To Repair a 2JZGTE Sub Throttle Actuator article, remove the four screws holding the actuator in place.
Remove the actuator and look at the throttle body opening machined into the housing.
Next take a feeler gauge and measure the runout between the throttle stop screw and the subthrottle valve. You do not want any gap here, because you want the sub throttle to be completely shut against the stop screw.
Next take your multimeter or voltmeter and check the pins on the subthrottle position sensor on your 2JZGTE engine set.
This subthrottle position sensor is part number 89452-33010, and you’ll need to test this subthrottle TPS in order to determine if your TRAC unit is working okay.
Take your voltmeter or multimeter and measure the resistance between the last two pins, labeled E2 and IDL in the image above. Remember that your stop screw should be set with no gap between the rotor of the subthrottle position blade and the stop screw.
Test the resistance between E2 and IDL and the resistance here should be lower than 0.5 kΩ fully closed. Now fully open the sub throttle blade and watch the resistance rise accordingly. There should be no gaps or jumping in resistance, and at wide open throttle you should have 1 MΩ or higher resistance value between E2 and IDL.
Loosen the two screws on the subthrottle position sensor, and rotate until the TPS deflects. When you have the resistance set, tighten down the screws and you have now tested your 2JZGTE subthrottle position sensor.
To eliminate the sub throttle position sensor and blade all together, simply undo the 4 screws as before.
Rotate the sub throttle blade all the way open using a 12mm wrench. Using a bar reach into your throttle body and keep the throttle blade cranked open and gun down on the 12mm wrench to keep it open permanently. Keep in mind that the housing is aluminum and can be damaged if tightened too much.
It may take a few tries before you can get the subthrottle blade open 100% and stuck there, but doing so will effectively eliminate the TRAC portion of your motor. We also included a ECU wiring pinout for the sub throttle position sensor below.
This does it for our How To Repair a 2JZGTE Sub Throttle Actuator, please leave us any questions or comments below!