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Michael Moore
Category: Chevy
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2003 Chevrolet Tahoe: computer displayed Reduced Engine Power

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I have a 2003 Chevrolet Tahoe 5.6 liter engine. Two days ago, I started it up, and the computer displayed "Reduced Engine Power". It was reduced alright. I made it to a friend's house. Later, I started it up and it ran fine. Yesterday it did it again. Today it did it again. The check engine light came on. I checked the codes with a scanner I had in the car, and the 2 codes displayed were P0120 and P2135. Are these codes related to the reduced engine power? This reduced engine power happened once before, about 1-1 1/2 years ago. A mechanic replaced the in-line fuel filter...I don't know what else. I also had the fuel filter replaced in the tank. What do you think the problem is, and what needs to be done to fix it?
Fred Combs
There is a problem with the wiring at the throttle body. The throttle is eletrical and no longer has a cable. The wiring harness makes a poor eletrical connection at the throotle body on the front of the engine. To repair this concern, you need to replace the connector. Your local dealership should have this part. It comes with a connector and new wires that you splice in to the old harness. Its best to cut the harness about 6 inches from the connector and install the new part.
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#PIP3089B: SES Light And Reduced Engine Power DTC P0120 P0220 P1516 P2135 - keywords accelerator actuator APP blade body connector connection DTC L33 L59 LH6 LR4 LM7 LS1 LS2 LQ4 LQ9 module position reduce sensor - (Oct 31, 2006)

Subject:SES Light and Reduced Engine Power DTC P0120 P0220 P1516 P2135
Models:2004-2006 Buick Rainer
2005-2006 Cadillac CTS-V
2003-2006 Cadillac Escalade
2003-2006 Chevrolet Avalanche, Corvette, Express, Monte Carlo, Silverado, SSR, Suburban, Tahoe, Trailblazer
2003-2006 GMC Envoy, Savana, Sierra, Yukon
2003-2006 Hummer H2
2005-2006 Pontiac GTO
Equipped with a 4.8 5.3 6.0 or 7.0 V-8 Engine

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.


A vehicle may be brought into the dealer for a reduced power message, and DTCs P0120, P0220, P1516, P2101, or P2135.

The Throttle Actuator Control (TAC) / throttle body type trouble codes, may be caused by a loose wiring crimp at the throttle body connector, or a broken throttle body circuit.