PIP5282

Bulletin No.: PIP5282
Date: Apr-2015
Subject:
Engine Oil Life Monitor Operation Calculation
Models:
2010 - 2015 All Passenger Cars And Light Duty Trucks
with Oil Life Monitor System
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
Since 2010 all GM vehicles have been equipped with the oil life monitor (OLM) system
The monitor calculates the percent of oil life remaining, based on 3 pathways
The OLM starts its calculation for all pathways after the first 50 miles to account for marshalling and time before sale. Subsequently, calculations begin
immediately after each reset.
Recommendation/Instructions
Oil Life Monitor Calculation Pathways:
1.
Engine revolutions- Oil life starts with a fixed number of revolutions and will decrease with each revolution. Cold / hot coolant temp readings have
multipliers that reduce engine revolutions pathway quicker depending on how far from the normal oil temperature the vehicle is operating.
Note: If engine coolant temp gets above 260F, engine overheat condition, the oil life will go to 0%.
2.
Mileage from last reset – Starting with MY 2013, the OLM is capped at 7500 miles for all GM powertrains except the Volt. In perfect conditions a vehicle
would reach 7500 miles from the last reset and the oil life left would be 0%.
3.
Time- This pathway is a liner function, a fixed decrease in oil life for a given time after the oil life is reset. The oil life will drop to 0% after 1 year
regardless of the amount of engine revolutions or how many miles since the reset.
Note: The Volt uses a 2 year timer instead of 1 year. It also uses the engine revolution counter. It does not use the mileage pathway to count down.
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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