Information On AFM DFM Usage – 2014-2020 Cadillac Chevrolet GMC

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Bulletin No.: PIP5663
Published date: 07/31/2019
Preliminary Information
PIP5663 Information On AFM DFM Usage
Models

Brand: Model: Model Years:

VIN:
from to

Engine: Transmissions:

Cadillac CTS-V 2016 – 2019 All All 6.2
LT4 All
Cadillac Escalade 2015 – 2019 All All 6.2
L86 All
Chevrolet Camaro 2016 – 2019 All All 6.2 LT1
LT4 All
Chevrolet Corvette 2014 – 2019 All All 6.2 LT1
LT4 LT5 All Chevrolet Silverado LD 2014 – 2019
All All 4.3L LV3 5.3 L83 6.2 L86 All Chevrolet Silverado 1500 (New Model)
2019 All All 4.3L LV3 5.3 L84 6.2 L87 All Chevrolet Silverado 2500
3500 2020 All All 6.6 L8T
All
Chevrolet Suburban 2015 – 2019 All All 5.3 L83
6.2 L86 All
Chevrolet Tahoe 2015 – 2019 All All 5.3
L83 6.2 L86 All GMC Sierra Limited 2014 –
2019 All All 4.3L LV3 5.3 L83 6.2 L86 All GMC Sierra 1500 (New Model)
2019 All All 4.3L LV3 5.3 L84 6.2 L87 All GMC Sierra
2500 3500 2020 All All 6.6 L8T
All
GMC Yukon Models 2015 – 2019 All All 5.3 L83 6.2
L86 All

Involved Region or
Country North America
Condition AFM / DFM usage
Cause Informational
Correction:
AFM
To provide maximum fuel economy under light load driving conditions, the engine control module
(ECM) will command the cylinder deactivation system ON to deactivate engine cylinders 1, 7, 6, and
4, switching to a V4 mode. The engine will operate on 8 cylinders, or V8 mode, during engine
starting, engine idling, and medium to heavy throttle applications.
AFM – active fuel management strategy which deactivates the lifters on specific cylinders. On V8
engines it deactivates half of the cylinders (1,7,6, and 4) and on V6 engines it deactivates
only 2 of the cylinders (3 and 6).
LOMA – lifter oil manifold assembly is only used on legacy AFM applications
DFM (Dynamic Fuel Management)

Dynamic Fuel Management (DFM) is recognized as active fuel management technology with the
additional ability to deactivate any combination of cylinder valves for an internal combustion
engine. This technology combines millisecond-accurate torque control with cylinder deactivation to
optimize fuel consumption of spark ignited engines. The control of every cylinder event optimizes
engine operation such that peak effi ciency is obtained throughout the range of engine operation.
DFM extends cylinder deactivation to all cylinders, which allows for a large variety of firing
sequences. DFM can have rotating cylinder deactivation patterns as well as fixed patterns. For
rotating patterns, which cylinders are being deactivated can change with each subsequent engine
cycle.
Transitions between firing sequences is done in a continuous fashion, making the transitions
seamless and transparent to the vehicle operator.
DFM – dynamic fuel management which can deactivate the lifter on any cylinder at any time. Unlike
AFM, this can result any many different types of firing patterns, some of which are fixed patterns
(lik e ¼, ½, ¾) and others which are rotating (like 1/5, 1/3, 2/5, 2/3). This is only available
on small block engines (L84 and L87).
OCV – oil controlled valve is only used on small block engines. These provide faster response
times than L OMA and are required for DFM (on L84 and L87). OCVs are also used on L82 for AFM.

Below is a AFM DFM usage chart
Vehicles AFM
VLOM

4 Cylinder Deac.

DFM. OCV’s

FDFMNone Notes

Cadillac CTS-V LT4 Yes Yes No No
Always active
Camaro LT1 Yes Yes No No Automatic
only. AFM not active with
Manual trans
Camaro LT4 Yes No No No
Has the hardware, Not active Corvette LT1 Yes Yes No
No Auto Trans active, Manual Trans active
in ECO only
Corvette LT4 Yes Yes No No Auto
Trans active, Manual Trans active
in ECO only
Corvette LT5 No No No No Yes
No hardware on LT5 Escalade L86 Yes Yes No No

Silverado /Sierra L83, L86
Suburban / Tahoe / Yukon L83, L86

Yes Yes No No

Yes Yes No No

Silverado /Sierra L82 No Yes Yes No Silverado /Sierra L84
No No Yes Yes Silverado /Sierra L87 No
No Yes Yes

Silverado /Sierra HD
L8T

No No No No No hardware on L8T

Silverado /Sierra LV3 Yes Yes No No

GMT610 Van LV1 No No No No
No hardware on LV1 GMT610 Van L8T No No No No
No hardware on L8T
Version History
Version 1
Modified 07/31/2019 – Created on

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