throttle position sensor

[Guest jsocool]

anyone out there with experience with the tps? i pulled my code which ultimately said to change the tps. as a newone costs like $290 - $350,i'd like to avoid that if at all possible. my question is this: is it possible to clean the sensor itself somehow and avoid replacement? Any tips for removal other then making matchmarks? Anyone got a spare tps they want to unload?

 

thanks

[Guest Legacy777]

I would recommend testing it first. If you don't have a service manual, get one.

 

Here's the procedure out of the chilton's manual to test the TPS switch.

 

1. Turn the ignition switch ON.

2. Measure the voltage between the ECU connector terminal and ground. Voltage should be as follows:

Terminal 2 and ground: 4.4-4.8 volts with the throttle fully open

Terminal 2 and ground: .7-1.6 volts with the throttle fully closed

Terminal 3 and ground: 5 volts

Terminal 1 and ground: 0 volts

3. Ensure voltage smoothly decreases in response to throttle opening. If measurements are not within specification, check and repair ECU terminals or harness.

4. Disconnect the connector from the throttle sensor. Measure the resistance between throttle sensor terminals 2 and 3. Resistance should be 12 kilo-ohms.

5. Measure the resistance between terminals while slowly opening the throttle valve from the closed position. Resistance should be as follows:

Terminals 2 and 4: 10-12 kilo-ohms with the throttle valve fully closed

Terminals 2 and 4: 3-5 kilo-ohms with the throttle valve fully open

6. Ensure resistance smoothly increases in response to throttle opening. If measurements are not within specification, replace the throttle sensor.

7. Disconnect connectors from ECU and throttle sensor.

8. Measure resistance between ECU connector and throttle sensor connectors. Resistance should be as follows:

ECU terminal 1 and throttle sensor terminal 2: 0 ohms

ECU terminal 2 and throttle sensor terminal 4: 0 ohms

ECU terminal 3 and throttle sensor terminal 3: 0 ohms

9. Measure resistance between throttle sensor connectors and ground. Resistance should be as follows:

Terminal 2 and ground: 1 mega-ohm minimum

Terminal 4 and ground: 1 mega-ohm minimum

Terminal 3 and ground: 1 mega-ohm minimum

10. If resistance is not within specification, check and repair the harness or connector.

 

I'll try and scan in the sensor wiring diagram tomorrow at work, so you know what pins are what.

[Guest boybill]

Try subaru-svx.net There is some posts on cleaning the tps. Search under tps. If you choose to clean it, be careful when you blow air through it to dry it out. I would use canned air for cleaning electronics as opposed to an air compressor. I damaged mine with too much air pressure, and had to buy a new one.$$$ouch$$$. This was what I was trying to avoid in the first place. Good Luck, BillC.

[Guest Legacy777]

Here's the scanned schematic for the sensor

 

[Guest jsocool]

Thanks josh and everyone else, I know what i'm doing my next day off, can't wait to fix the problem and get rid of that pesky "check engine" light. I'll let everyone know how it goes.

[Guest SmashPDX]

Someone let me know when this thread is done and I'll archive it-- with that diagram it's particularly good.

 

Josh, would like to know how 'permanent' the location (i.e., server and URL) of that pic is, if the server isn't owned by you and the pic moves it'll break the link. I have my own server & domain so I'd be glad to give it a permanent home. Let me know.

[Guest Legacy777]

Server is my server. It's a pretty stable server, other then me occasionally rebooting. It would be down when I move, but I'll have it back up when I finish moving and stuff. I'll always have cable or dsl....I can't deal with dial up

 

I may have to go through some of my old archived posts and edit pic links off my psu account when I move my site.....still need a good domain....any ideas anyone??

[Guest jsocool]

O.K, I went to www.subaru-svx.net/archive/article/php?message=50892 Sorry for not posting it as a link,I'm Not that bright.

 

Here are the directions I found for cleaning a tps.

 

1. Carefully scribe the rotational position of the tps, disconnect the cable, remove the 2 screws holding the tps.

 

2. Look into the connector end of the tps and observe a very small hole between the pins. Using contact cleaner ( Radio Shack) and a small tube (like a wd-40 Tube, DO NOT USE WD-40) flush the unit completely,rotating the wiper several timesand letting the fluid drain from the shaft.

 

3. Repeat

 

4. Using canned air, blow through the hole until the unit is dry.

 

5. Reasemble,ensuring that the scribe lines match, reconnect.

 

*** moderator edit: fixed the link. ***

[Guest jsocool]

well, i followed the instructions for cleaning, and so far so good, however, the problem was inermittant, so I'll get back to everyone in a week or so with more conclusive results.

 

Just a note to anyone with this procedure in mind, according to the instructions on my previous post, there is supposed to be a small hole in between the pins that one can squirt the contact cleaner through, however there wasn't a hole on mine, just some spaces around the edges of the unit that allowed access.

[Guest Legacy777]

Archive me

 

Bump, bump

 

Archive me some more.....come on....I dare ya....double dog dare.......tripple DOG DARE YA!

 

 

Ahh the holidays.....it just can't be christmas with the movie, "A Christmas Story"