throttle position sensor TPS high
Pro
Joined: Oct 1999
Posts: 515
Likes: 0
From: Nashua NH
code 21 TPS signal voltage high
Code 21 will set if:
TPS signal voltage is greater than 2.5V for 4 sec:
Air flow is less than 12 gm/sec
Engine speed less than 1200 RPM
TPS is located on passenger side of throttle body. has a 3 pin connector. Backprobe pins A and B with DVM to check voltage. Adjustment is made with slotted screws on side. Correct TPS voltage with key on engine off is .54V, +/- .07V
Code 21 will set if:
TPS signal voltage is greater than 2.5V for 4 sec:
Air flow is less than 12 gm/sec
Engine speed less than 1200 RPM
TPS is located on passenger side of throttle body. has a 3 pin connector. Backprobe pins A and B with DVM to check voltage. Adjustment is made with slotted screws on side. Correct TPS voltage with key on engine off is .54V, +/- .07V
Team Owner
Joined: Jan 2003
Posts: 20,304
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From: Summerland B.C. Canada
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
If the TPS voltage is 4.84 with the engine off but key 'ON', then then TPS is either
defective or
the screws have somehow loosened allowing the TPS to physically move or
you checked using the wrong two wires (use the TOP and MIDDLE wires).
Jake
defective or
the screws have somehow loosened allowing the TPS to physically move or
you checked using the wrong two wires (use the TOP and MIDDLE wires).
Jake
Last edited by JAKE; Feb 26, 2010 at 12:48 PM.
Team Owner
Joined: Jan 2003
Posts: 20,304
Likes: 240
From: Summerland B.C. Canada
If you are measuring the correct wires(the top 2), I would think there is a failure of the TPS. I don't think there is enough adjustment to reach 4.84.
Did you follow the test for 21 ?
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Slingshot
Joined: Dec 2001
Posts: 3,817
Likes: 24
From: Charlotte NC
TPS test harness
Mid America Corvette parts has a TPS test harness for about $15 that works great. Here is a photo, URL link and test instructions. 
http://www.mamotorworks.com/corvette?frame=1.900
http://www.mamotorworks.com/corvette?frame=1.900
Thread Starter
Instructor
Joined: Jan 2010
Posts: 123
Likes: 1
From: Lakeland Florida
Mid America Corvette parts has a TPS test harness for about $15 that works great. Here is a photo, URL link and test instructions.
http://www.mamotorworks.com/corvette?frame=1.900
http://www.mamotorworks.com/corvette?frame=1.900
Team Owner
Joined: Jul 2004
Posts: 28,424
Likes: 3,276
From: Hartford WI
Thread Starter
Instructor
Joined: Jan 2010
Posts: 123
Likes: 1
From: Lakeland Florida
tps
be 0.45v. Guess i need a new one.
Steve
Last edited by lexman52; Feb 26, 2010 at 07:48 PM.
Team Owner
Joined: Jul 2004
Posts: 28,424
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From: Hartford WI
Team Owner
Joined: Jul 2004
Posts: 28,424
Likes: 3,276
From: Hartford WI
That is at idle. My point is there are 3 wires. Reference (5V), ground and signal to the ECM. If I am correct and the reference is 5V, max you can get as a signal is 5V. So, if you get 5.7V or 6.23V, I am not sure your reference is right.
This is kinda like me giving you $5 to get me a can of soda. Even if you don't get the soda, how do you get more than $5 in your pocket, assuming it was empty before I gave you the money.
This is kinda like me giving you $5 to get me a can of soda. Even if you don't get the soda, how do you get more than $5 in your pocket, assuming it was empty before I gave you the money.
