throttle position sensor?
Thread Starter
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Joined: Oct 2011
Posts: 261
From: Pennsylvannia
throttle position sensor?
My car runs very well when I need power, but when I accelerate slowly, my transmission will bang into 2nd and 3d gear. Is it because of the throttle position sensor? It shifts very smoothly under normal acceleration.
The transmission also seems to go into gear rather quickly, almost in a rough fashion.
The transmission also seems to go into gear rather quickly, almost in a rough fashion.
Last edited by 97z28k&N; Feb 27, 2012 at 05:46 PM.
Registered User
Joined: Dec 1969
Posts: 27,725
From: Little Rock, AR
Re: throttle position sensor?
Scan for transmission trouble codes. It will sometimes default to acting like that when there is some trouble. Trans codes do NOT light light the SES.
Last edited by shoebox; Feb 27, 2012 at 09:21 PM. Reason: added a NOT, LOL thanks Fred
Registered User
Joined: Dec 1969
Posts: 27,725
From: Little Rock, AR
Re: throttle position sensor?
LOL, typing on a tablet. Not as good as a keyboard.
Yeah, it might, but who says that is your trouble? It's more indicative of a transmission code and the mode the computer defaults to during one. You don't select an item and make the symptoms fit it, you let the symptoms lead you to the item.
Yeah, it might, but who says that is your trouble? It's more indicative of a transmission code and the mode the computer defaults to during one. You don't select an item and make the symptoms fit it, you let the symptoms lead you to the item.
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From: Hell was full so they sent me to NJ
Thread Starter
Registered User
Joined: Oct 2011
Posts: 261
From: Pennsylvannia
Re: throttle position sensor?
My SES light is not on. The symptoms I have been having are pointing to a faulty TPS, mentioned by a few 4L60E rebuild shops. I'm not rejectig Rob either, I will do what he is suggesting but I do not own a scanner.
Registered User
Joined: Dec 1969
Posts: 27,725
From: Little Rock, AR
Re: throttle position sensor?
You can use a scanner (not just a code reader) to observe the TPS and see if it is acting linearly. If it does not increase smoothly as you press the throttle, then it has a problem. The TPS is generally very reliable and not often a source of trouble. You can also use a multimeter and observe voltage between the dark blue and black wires as you move the throttle. Of course, you have to own a meter. The scanner is easier. Anyone that works on his own computerized car should invest in some way to scan and observe live data.
Administrator
Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
Re: throttle position sensor?
The following TPS codes turn on the SES light:
P0121 - Throttle Position (TP) sensor circuit insufficient signal activity
P0122 - Throttle Position (TP) sensor circuit low voltage
P0123 - Throttle Position (TP) sensor circuit high voltage
The following TPS codes do not turn on the SES light:
P1221 - Throttle Position (TP) sensor circuit intermittent high voltage
P1222 - Throttle Position (TP) sensor circuit intermittent low voltage
P0121 - Throttle Position (TP) sensor circuit insufficient signal activity
P0122 - Throttle Position (TP) sensor circuit low voltage
P0123 - Throttle Position (TP) sensor circuit high voltage
The following TPS codes do not turn on the SES light:
P1221 - Throttle Position (TP) sensor circuit intermittent high voltage
P1222 - Throttle Position (TP) sensor circuit intermittent low voltage
Thread Starter
Registered User
Joined: Oct 2011
Posts: 261
From: Pennsylvannia
Re: throttle position sensor?
You can use a scanner (not just a code reader) to observe the TPS and see if it is acting linearly. If it does not increase smoothly as you press the throttle, then it has a problem. The TPS is generally very reliable and not often a source of trouble. You can also use a multimeter and observe voltage between the dark blue and black wires as you move the throttle. Of course, you have to own a meter. The scanner is easier. Anyone that works on his own computerized car should invest in some way to scan and observe live data.
Registered User
Joined: Mar 2012
Posts: 7
From: Minisooota
Re: throttle position sensor?
Thank you, I will invest in a scanner. Are there any that you would recommend?[/QUOTE]
Amazon.com: ScanGauge II Ultra Compact 3-in-1 Automotive Computer with Customizable Real-Time Fuel Economy Digital Gauges: Automotive
My buddy uses this his for his Escape and it's got alot of cool engine readouts as well being a basic code reader. I don't mean to butt in, but I'm suspecting (hoping) the same for my '96 A4. Shifts into 2nd and 4th (sometimes 3rd) rough at subdued acceleration. Also, I don't believe it's going into OD: 2000 rpm at 55mph, and 2200 at 65mph? My Firebird with the 3800 would do around 1600 at 55mph. The only code that showed for me was a stored code P0179, which is a fuel composition sensor, but that wouldn't explain the hard shifts. Attempted testing the TPS for consistancy, but failed because I wasn't confident if it was the right sensor I was taking off. Found location in pic online for a '95 Z28, and I'll check voltage tomorrow if it's not still raining.
Amazon.com: ScanGauge II Ultra Compact 3-in-1 Automotive Computer with Customizable Real-Time Fuel Economy Digital Gauges: Automotive
My buddy uses this his for his Escape and it's got alot of cool engine readouts as well being a basic code reader. I don't mean to butt in, but I'm suspecting (hoping) the same for my '96 A4. Shifts into 2nd and 4th (sometimes 3rd) rough at subdued acceleration. Also, I don't believe it's going into OD: 2000 rpm at 55mph, and 2200 at 65mph? My Firebird with the 3800 would do around 1600 at 55mph. The only code that showed for me was a stored code P0179, which is a fuel composition sensor, but that wouldn't explain the hard shifts. Attempted testing the TPS for consistancy, but failed because I wasn't confident if it was the right sensor I was taking off. Found location in pic online for a '95 Z28, and I'll check voltage tomorrow if it's not still raining.
