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App sensor reading with scope Need scope experts
- Columbus450
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4 years 7 months ago - 4 years 7 months ago #33188
by Columbus450
App sensor reading with scope
Need scope experts was created by Columbus450
Ok guy's im kinda new to scopes , I'm troubleshooting and issue with APP sensor 2 low voltage ,I scoped the app sensor 2 signal and it drops out koeo, well below spec @
.325 volts so i ordered acc pedal cause its confirmed bad.
Well this is were i get confused i went back and tested it again wanted to test the 5 volt rev and ground which were kinda iffy before but i was set on peak detect and this is what i got ,(KOEO TPS PLATE OPEN AND CLOSES WITH THROTTLE APP ACTUATED )
-This is 5volt rev pic below -
-Also ground with peak detect off and on both look horrible -
-app 2 signal peak detect on and off with no filter-
I was getting very hashy readings from my app sensor while opening and closing so i was thinking the tps butterfly is corrupting/altering my readings so i un plugged the tps tac motor wich was opening and closing during my app testing right,,,, and now my app sensor GROUND,5 V REV ,AND APP 2 signals are perfect filter off and peak on or off look GREAT!!! when tps is plugged back in app readings look like crap again worse with peak detect on ,in confused, please help
Sent from my SM-N960U using Tapatalk
.325 volts so i ordered acc pedal cause its confirmed bad.
Well this is were i get confused i went back and tested it again wanted to test the 5 volt rev and ground which were kinda iffy before but i was set on peak detect and this is what i got ,(KOEO TPS PLATE OPEN AND CLOSES WITH THROTTLE APP ACTUATED )
-This is 5volt rev pic below -
-Also ground with peak detect off and on both look horrible -
-app 2 signal peak detect on and off with no filter-
I was getting very hashy readings from my app sensor while opening and closing so i was thinking the tps butterfly is corrupting/altering my readings so i un plugged the tps tac motor wich was opening and closing during my app testing right,,,, and now my app sensor GROUND,5 V REV ,AND APP 2 signals are perfect filter off and peak on or off look GREAT!!! when tps is plugged back in app readings look like crap again worse with peak detect on ,in confused, please help
Sent from my SM-N960U using Tapatalk
Last edit: 4 years 7 months ago by Columbus450.
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4 years 7 months ago #33192
by Cheryl
Replied by Cheryl on topic App sensor reading with scope
Surprised you couldn’t see that same signal on other sensors that share the 5 volt ref
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- Columbus450
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4 years 7 months ago #33204
by Columbus450
Replied by Columbus450 on topic Re:App sensor reading with scope
Yeah I get great signals when the TPS is unplugged it’s almost as if the Tps is pulling my signals down,But if that was the case this vehicle would be a no start it’s only throwing a code for app 2 -P2127-
I only get the bad readings on the App Circuit
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I only get the bad readings on the App Circuit
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- Columbus450
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4 years 7 months ago #33207
by Columbus450
Replied by Columbus450 on topic Re:App sensor reading with scope
I am testing the APP circuit loaded by moving the pedal up and down up and down, as I’m doing this the throttle butterfly valve is opening and closing key on engine off,These measurements still don’t seem normal even though work is being performed and energy is being used by me operating the pedal,What could be causing this I’m not even getting a code for the TPS
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- Columbus450
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4 years 7 months ago #33230
by Columbus450
Replied by Columbus450 on topic Re:App sensor reading with scope
Need scope experts
Has anybody ever dealt with this before?
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4 years 7 months ago #33316
by Columbus450
Replied by Columbus450 on topic Re:App sensor reading with scope
Need scope experts
Believe I found the problem looks to be a bad computer ground, The APP circuit and the TPS along with map sensor share ground internally inside of the computer ,So I gave the computer a better external ground and it seems to have made my readings a lot better
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4 years 7 months ago #33317
by John Curtis
Making Pressure Differential Sensors (PDA Sensors) for pressure pulse diagnostics.
Currently servicing Central Texas.
Replied by John Curtis on topic App sensor reading with scopeNeed scope experts
Definitely a bad ground.
Making Pressure Differential Sensors (PDA Sensors) for pressure pulse diagnostics.
Currently servicing Central Texas.
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