OT Toyota Throttle Position Sensor location?

[Bud in FLA]

Looks like I gotta change the TPS on my son's '98 Tacoma 6 cyl 4x4 truck. The computer at Advance Auto said that's why the check engine light was on, anyway.
I think I saw it at the top of the gas peddle under the dash. Looks like a good time for him to learn how to be a contortionist!
Anyone know of any "gotchas" I need to know about before I try this?
Thanks for any info!

 

[Jiles]

Don't know about your model Toyota, but all throttle Position Sensors I have worked with, are mounted on the throttle body. If you don't know, the throttle body is where the carburetor used to be. It will have an electrical connector and the sensor is activated by the opening and closing of the butterfly in the throttle body.
Try this--with ignition off, disconnect and reconnect the wireing connection several times, note if the connections are clean. Many times, a sensor is said to be bad and it is a bad connection. It cost nothing and is worth a try.

 

[Old Ford Mechanic]

Go to Advance Auto Parts or one of the discount auto parts stores and ask for a"Haynes Service Manual" that covers his truck.Then sit down and familarize yourself to this job before you attempt it.This may help you do the job or it may help you decide to let a service shop do it for you.A scanner that reads the codes like the guys use identifies circuits the problem is in but,its up to the mechanic to locate,troubleshoot and replace/repair the culprit.And also remember that once you install an electrical part such as a sensor they are yours.No refunds given if they don't solve the problem.Today's electrical systems and emisson systems on automobiles are not "NOVICE MECHANIC" friendly.

 

[bradk]

Under hood on throttle body opposite end of throttle linkage.

 

[Bud in FLA]

I'll throw the heat gun to it tomorrow and check the connections! It's about -2º here right now - don't want to break the plastic.
I pretty much quit working on cars & trucks when they went to computers. I can overhaul a steam or combustion turbine but my fingers and eyes just don't work on little parts anymore!
Thanks for all the info! I'll make sure my son gets himself a copy of the manual, too!

 

[Goose]

If it's adjustable, you might have some grief getting it adjusted.

I just had to replace the one on my Olds 88. A TPS is nothing more than a variable resistor. It has an input reference voltage, usually about 5 volts, and the output voltage varies with the position of the throttle to tell the computer the position of the throttle. The computer then determines fuel mixture, shift points on the trans, etc.

Problem was, on my Olds it's adjustable, and two replacements, OEM and NAPA, both had identical resistance readings, but different from the old one I took off. It took me a month of trial and error to get it adjusted right. Even my buddies at the NAPA shop, whom I'd worked with once in the past, couldn't help.

 

[scotc]

I don't know about adjusting it on a Toyota, but with Chrysler's setup you plug it in and don't touch the throttle when you start it, and it will reset the low idle to what the sensor is telling it.

If there is a cable from the pedal to the throttle body, the sensor is underhood (4.3 chevy, most 4 cyl. and 3.9/5.2/5.9 mopars), if there is no cable to the throttle body the tps will be on the pedal (new hemi, duramax, others)

 

[Bud in FLA]

Operation was a success. Even better, all I had to do was provide tools, build a fire in the heater and hold the light and heat gun! The heat gun was to keep the plastic parts (& fingers!) from snapping off. Even with the heater it was 16º inside the shop.
The check engine light was still on so my son drove it back to the parts place and they cleared the code for him so he's a happy camper again.

I'd planned to insulate the shop ceiling this weekend but it's too cold to spend much time out there if I don't have to!

I spent a lot of years as a welder, machinist and precision millwright before I wound up as a turbine outage planner...I'm happily "retarded" now with NO intentions of learning too much about how to work on modern vehicles! My old '68 Ford is fun to work on - no computer!

Thanks again for the help!!!

 

[Brian Jasper co. Ia]

The sensor on the pedal is not a throttle position sensor. It is the accelerator pedal position sensor. Totally different in what they do. The pedal position sensor is used on vehicles not having a throttle cable. Gasoline engines with no throttle cable have a throttle actuator to provide throttle blade movement. Having the throttle controlled by an actuator simplifies other systems like eliminating idle air control for idle speed, a separate cruise control actuator is eliminated, traction control is enhanced by being able to override the driver's over application of throttle.
The throttle position sensor is always directly connected to the throttle shaft. Diesels stopped using throttle position sensors also known as fuel injection pump lever position sensor when mechanical injection pumps disappeared. On GM engines, there are 2 TP sensors internal to the throttle actuator. They are only serviced as a complete throttle body.

 

[scotc]

When I was at Schneider I had a throttle sensor go bad and it wouldn't let the detroit idle off, I told the shop that I had to spray a bunch of Blaster into the TPS to get the motor to idle back and they figured out what I was talking about, and with the group at the yard I worked out of, well, I figured it was a close enough term as they measure throttle input just from different places. And the computer uses the info differently.