Bulletin No.: PIT5387B
Date: 13-Jan-2016

Subject:

Radio HVAC IPC Blank Out When Operating A Snow Plow

Models:

2014 Chevrolet Silverado 1500
2015-2016 Chevrolet Silverado
2014 GMC Sierra 1500
2015-2016 GMC Sierra
With Snow Plow Prep Package (RPO VYU)

This PI was superseded to update Administrative Details. Please discard PIT5387A.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern
Some owners may experience any of the following: IPC cluster/radio/HVAC display blanks out, Bluetooth phone or Pandora connection dropped, the radio
station or volume changes when operating the snow plow.
A snow plow places very high electrical loads on a truck's charging system when it is being operated (during plow movement). It demands the highest load (as
high as 200 amps) when it is raised up completely or turned to either left or right maximum angle. As this load is turned on and off, the truck's charging system
has to react within a faction of a second to either increase or decrease its output to meet the plow's requirements.
There is no way for the truck's charging system to know when the driver is going to operate the snow plow, and in some cases, when the load is suddenly
turned off, the charging system may momentarily over-charge for a fraction of a second. If this happens it can cause the various complaints listed above.

Recommendation/Instructions
Please advise the customer that engineering is aware of this concern and working on this issue. In the meantime, there are a couple things a driver can do to
help minimize the concern:
–

When plowing, turn on various electrical loads like the HVAC blower on high, headlights, heated seats, etc. which may help absorb any slight over
voltage condition.

–

Minimize moving the plow to the max up/left/right positions, which will decrease the large electrical load swings on the charging system

–

Minimize engine RPMs just as the desired plow movement (up/left/right) is concluded. This will reduce the charging system over voltage condition as the
load is disconnected.

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.

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