Hello, new member, first post. Lokor help. I have a 2012 yukon denali 6.2. It's new to me so I don't know much about its past. The problem I have is with reduced engine power, some times when I start to pull out from a stop it will go into reduced engine power but it never has check engine light or had a code thrown. The check engine light works but doesn't come on when this happens. Anyone point me in the right direction to diagnose this. I have replaced the tps on the throttle body, just throwing money at it because that is what my Silverado needed few years ago.
Reduced engine power without cel
- Thread starter travstick
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Are you getting a Reduced Power message on the DIC or just noticing a reduction of power?
How has your transmission been acting for you? Condition of transmission fluid?
Do you have the ability of putting a scan tool on it and watch the live data to see what you can see?
How has your transmission been acting for you? Condition of transmission fluid?
Do you have the ability of putting a scan tool on it and watch the live data to see what you can see?
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Welcome to the Forum from NH.
Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.
I hope that you will become a participating member in the Forum's discussions.
Pics of the truck, please.
You are already receiving sage advice from the knowledgeable folks on this Forum.
Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.
I hope that you will become a participating member in the Forum's discussions.
Pics of the truck, please.
You are already receiving sage advice from the knowledgeable folks on this Forum.
Yes, I get the message on the dic, transmission seems fine but it is me to me, and yes I've got a scan tool that will do live data
Since the DIC shows the message, there should be a powertrain code.
CaptainAmerica1
Full Access Member
Check ltft against stft and report back. Mine did this when I developed a vacuum leak in my intake manifold.
bad/ loose cable at gas peddle , throttle body controller actuator or loose cable at the throttle body
Stage2Tahoe
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Stage2Tahoe
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I just had the same problem with my 03 Tahoe. I replaced the TCM and the TPS and neither fixed the problem completely. I had to replace the throttle body. The drive motor for the throttle body was going bad causing the throttle blade to flutter at idle which caused rough idle and reduced engine power. I however got a code.
That's what I thought too
It's drive by wire
What should the numbers be? Do this at idle or try to see what they are when it goes into reduced power? I normally work on all my vehicles and I know what long and short fuel trim is, but I don't really know much about using scan tool other than the typical check codes stuff
I've been thinking throttle body but you know how throwing money at a problem is......I can make the "rep" happen sometimes with it still in park by just blipping the throttle and it seems to me like it takes too long to idle down after it's been rev'd up. Like maybe the throttle body is too slow or is this normal?
If there is a discrepancy between the accelerator position sensor and the throttle position sensor, it can cause an issue resulting in a reduced power condition.
The behavior noted in that post leads me to believe the idle air control (IAC) isn't able to manage the airflow at idle. Classic signs of a dirty throttle body butterfly that won't close all the way. Suggest you clean it with throttle body cleaner and see if that does anything for your issue.
As also noted by @wjburken a discrepancy between those two sensors can wreak havoc. If you can graph the movement of the accelerator position sensor and the throttle position sensor on the throttle body, you should be able to see any variations between them, or a dropout in either one. One thing to check while you're poking around the TB are the wires to the sensor; inspect them carefully for broken or compromised wires within about a foot or so of the TB. Sometimes they break underneath the insulation.
No it's not 2012 is electronic throttle body and e-gas pedal , as it has been electronic since 2004 model year...
most likely if you have all ready replaced the throttle body sensor the gas peddle sensor is broken..
try wiggling the pedal around see if it does it still
check with the OBD2 reader with live data the inverse and outverse have to match
No match = REP on the display
GM GENUINE PArt 23362231
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That’s the definition of “drive by wire” vs “drive by cable”. The throttle gets its command through a wire that powers its actuator vs a cable that is physically connected to the pedal.
I cleaned the throttle body when I replaced the tps, I checked the wires at the plug but will check then further away from the tps.
I'm not sure what I'm looking for, what would be a sign of vacuum leak?
