PIP5069A

Bulletin No.: PIP5069A
Date: Jun-2015
Subject:
Lack Of Power On Initial Acceleration From A Stop When the Ambient Temperature Is 103F Or Greater
(U.S.A. Dealers Only)
Models:
2010-2014 Chevrolet Avalanche, Silverado, Suburban, Tahoe Models
2010-2014 GMC Sierra, Yukon
Models with 5.3L Cast Iron Block Engine (Only RPO LMG)
This PI was superseded to update Administrative Details and Recommendation/Instructions. Please discard PIP5069.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
In rare instances, some customer's may complain of a lack of power on initial acceleration from a stop when the ambient temperature is approximately 103F or
greater and may include engine detonation or pre-ignition type events as temperatures approach 120F.
The customer operates the vehicle with low octane fuel.
Upon inspection, no DTCs will be present.
If DTCs are present or if this happens at lower ambient temperatures, this PI does not apply.
This is most likely to occur on vehicles with a 3.08 axle ratio
Recommendation/Instructions
If this concern is encountered, perform SI diagnosis, document all test results, and repair as necessary.
If SI diagnosis does not isolate the cause of this concern, take a Tech 2 snapshot of the concern happening and note the Spark Parameter in the Ignition Data
List. If it drops near/below 0 degrees during the concern,
Look to see if there is a cylinder that shows any knock, if so perform a top engine clean.
If the concern is still present, then switching to premium fuel (91 octane or higher) with detergents (Top tier fuel) when ambient temperatures exceed 110 degs
F.
This should provide a slight improvement in engine performance when ambient temperatures are high especially as temperatures approach 120F.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the
remaining steps do not need to be performed.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may
occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools,
safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that
your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
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