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2003 Suburban. Reduced Engine Power

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Old Aug 31, 2011 | 09:25 PM
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Question 2003 Suburban. Reduced Engine Power

Any solutions? My dads suburban randomly gets a reduced engine power reading every now and then. We have gotten it to disappear but turning off the ignition then turning it back on again, but then it reappears again during another drive or during the same drive.

Any possible fixes? from my research i've heard throttle body harness re wiring, checking battery connections.

Thanks.
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Old Aug 31, 2011 | 09:30 PM
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Got the codes out of it?
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Old Aug 31, 2011 | 09:56 PM
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Or perhaps there actually is reduced engine power? Maybe it's trying to tell you to make it faster...

How would the car be able to tell its power is reduced though?
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Old Sep 1, 2011 | 09:10 AM
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Go to your local AP store and have the code scanned as that message appearing in the msg center is likely due to the PCM putting the car in limp mode due to problems - O2's, Misfire, Fuel, overheat, etc...
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Old Sep 1, 2011 | 09:29 AM
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You need to see immature codes as well as set ones.

One common cause of this "reduced power" mode is a
disagreement between the various airflow calculation
modes (MAF vs speed-density, speed-density vs
alpha-N). The PCM sees that one of these things is
not like the other, and plays it safe. If the electric
throttle body is coked up its position may not be
quite what it's supposed to and you can get a
disagreement between angle-RPM (alpha-N)
estimate and the MAP-RPM (speed density) one.

Probably either a hygeine or blind parts swapping
problem at the bottom of it.

Electric throttle is the Devil.
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Old Sep 1, 2011 | 09:31 AM
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Originally Posted by jimmyblue
You need to see immature codes as well as set ones.

One common cause of this "reduced power" mode is a
disagreement between the various airflow calculation
modes (MAF vs speed-density, speed-density vs
alpha-N). The PCM sees that one of these things is
not like the other, and plays it safe. If the electric
throttle body is coked up its position may not be
quite what it's supposed to and you can get a
disagreement between angle-RPM (alpha-N)
estimate and the MAP-RPM (speed density) one.

Probably either a hygeine or blind parts swapping
problem at the bottom of it.

Electric throttle is the Devil.
03 burb (5.3 vortec) does not have the electronic tb, has the traditional cable linkage.

Get it scanned as a code WILL be stored!!!
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Old Sep 1, 2011 | 04:22 PM
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thanks guys, from me and my dad.
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Old Sep 1, 2011 | 09:59 PM
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Originally Posted by DAVE00
03 burb (5.3 vortec) does not have the electronic tb, has the traditional cable linkage.

Get it scanned as a code WILL be stored!!!
They where both set-ups in those years. have to ID the system on the vehicle, pretty easy lol...
But as said the PCM should have a reason for REP event & light request.
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Old Sep 2, 2011 | 11:13 AM
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I've never heard of a cable throttle vehicle having a
reduced power mode. There is no authority for that
(other than maybe punking the spark) without DBW.
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Old Sep 3, 2011 | 10:52 AM
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Originally Posted by jimmyblue
I've never heard of a cable throttle vehicle having a
reduced power mode. There is no authority for that
(other than maybe punking the spark) without DBW.
Correct it's done thru timing, and injector control. My 2000 Silverado had a limp mode and the cable tb was on the Vortec motor thru 2005 I believe.
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Old Oct 18, 2016 | 03:20 AM
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Originally Posted by DAVE00
03 burb (5.3 vortec) does not have the electronic tb, has the traditional cable linkage.

Get it scanned as a code WILL be stored!!!
are you saying all 03 suburbans don't have eelectronic throttle body?
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