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Fuel Trim Data from the OBD2 Scanner

Old Sep 8, 2018 | 9:41 PM
  #1  
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From: Elyria, OH
Default Fuel Trim Data from the OBD2 Scanner

Hi, I set up my tablet with some fuel trim data on my 2008 Chevy Express 1500 Cargo 4.3l, 225k, wondering if anyone can read what the sensors are telling. The first screen is just general revs, temps and pressures, the following three are fuel trim info at idle, 1500 rpm, and 2500 rpm (approximately).



From left to right this screen shows Injector ON time in milliseconds Bank 1 and 2. Short Term Fuel Trim % Bank 1 and 2. Long Term Fuel Trim % Bank 1 & 2. Oxygen (O2) Sensors Front and Rear Volts, Bank 1 & 2. Revs and intake temperature. At idle.



At about 1500 rpm.



At about 2500 rpm.
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Old Sep 8, 2018 | 10:00 PM
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When the number is negative the pcm is correcting by cutting fuel due to a sensed rich condition and when the number is + the pcm is adding fuel for a sensed lean condition. as long as the fuel trim is +/- 10% its all good.

you can use this data for detecting vacuum leaks, low fuel pressure, purge solenoid leaks.
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Old Sep 8, 2018 | 10:23 PM
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From: Elyria, OH
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Originally Posted by tech2
When the number is negative the pcm is correcting by cutting fuel due to a sensed rich condition and when the number is + the pcm is adding fuel for a sensed lean condition. as long as the fuel trim is +/- 10% its all good.

you can use this data for detecting vacuum leaks, low fuel pressure, purge solenoid leaks.
OK tech2, thanks, the vehicle runs good but will look into using the info for troubleshooting.
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