Bulletin No.:

Service Bulletin

Date:

19-NA-046
October, 2020

INFORMATION
Subject:

Brand:

Chevrolet

Information on Electronic Limited Slip Differential (eLSD) Operation and Driver
Information Center (DIC) Wheel Slip Screen
Model:

Model Year:
from

Camaro ZL1

2017

Camaro
ZL1 1LE

2018

Camaro
SS 1LE

2017

Corvette

2014

VIN:
to

from

to

Engine:
(6.2L)

Transmission:

LT4
2021

LT4
—

—

All
LT1

2020

LT1, LT4, LT5

Involved Region or Country

North America, Europe, Russia, Middle East, Israel, Argentina, Brazil, Bolivia, Chile,
Colombia, Ecuador, Paraguay, Peru, Uruguay, Japan, GM Korea Company, China,
Taiwan, Philippines

Additional Options (RPOs)

Equipped with AXLE POSITRACTION-LIMITED SLIP, ELECTRONIC (G96)

Condition

Some customers may question the information displayed on the DIC as it relates to the
Electronic Limited Slip Differential (eLSD) system.

Camaro DIC

System Information

5251019

Copyright 2020 General Motors LLC. All Rights Reserved.

Page 2

October, 2020

Bulletin No.: 19-NA-046

Corvette DIC

5251013

Photos of the Camaro and Corvette DIC screens are shown in the graphics above. This
bulletin will provide a general overview of the functions and operation of the eLSD system
in these vehicles.

eLSD Wheel Slip System Information
eLSD Coupling Percentage
The eLSD system is a relatively new piece of
technology that has been introduced to a very limited
number of performance vehicles. The goal of this
system is to provide an open differential when needed
(0%), and a locked differential (100%) when conditions
call for it. This system is capable of adjusting the
coupling from fully open to fully locked in as little as
.15 seconds.
Generally speaking, the eLSD system has an incredible
effect on the vehicle’s performance and handling.
When the driver is off the throttle, more eLSD coupling
adds stability, to a point. When the two rear wheels are
clutched together, in a turn, we are slowing down the
outside wheel and speeding up the inside wheel. This
keeps the vehicle feeling agile throughout the turn.
When the driver is on the throttle, the eLSD system can
shift the torque from the inside wheel to the outside
wheel to minimize inside wheel spin, as well as provide
a much better "feel" on how the car turns with the
throttle. More (but not too much) torque applied to the
outside wheel will help the car turn.
The respective DIC pages, as seen in the photos
above, are provided to the driver so that he or she can
monitor the % of coupling that the eLSD is currently at.
This is indicated by the yellow number on the top of the
DIC screen.

Here are some examples of what the driver may see
while monitoring this screen as it relates to the eLSD
system:
• Driving straight down the road - The eLSD system
will have a bit of coupling to add stability and
on-center steering feel. This will be a relatively
small amount (around 10% - 15%) and the number
will decrease slightly when making a lane change
or other steering input.
• When applying the throttle - The system will
increase the coupling under heavy throttle. The
driver may see around 40 - 50% coupling under
heavy acceleration in a track setting. This is to
maximize rear traction while cornering, while still
maintaining the feel of how the car handles
throughout the turn.
• Extreme lane changes and slalom events The largest coupling will occur during the most
aggressive dynamic maneuvers. The eLSD
clutches will nearly lock (100%) to add stability at
the right moment but open back up to allow the
vehicle to steer through a double lane change at
precisely the right times.
• Winter driving - If the vehicle is being driven in the
winter (being equipped with the appropriate tires),
and the driver is attempting to accelerate from a
stop with one wheel on ice and the other on dry
pavement, he or she will notice that the clutch
torque will increase on the DIC as a result of the
single wheel slipping. This will transfer torque to
the wheel with more available traction so that the
vehicle will accelerate smoothly.

Bulletin No.: 19-NA-046

October, 2020

•

Bleed events - Because the eLSD system is filled
with fluid, small amounts of air will accumulate in
the system over time. A small actuator is built into
the system in order to bleed these small amounts
of air from the system. Every few key cycles, the
driver may notice that the coupling percentage on
the DIC spikes up to 100% briefly. This will occur
at very low speeds and also while driving in a
straight line. This is completely normal and in no
way does this indicate a problem with the system.
There are many different algorithms, or calculations
used by this system. The amount of coupling that the
system delivers depends on many different factors.
They include (but are not limited to) vehicle speed,
throttle position, steering angle, yaw rate, available
traction, vehicle options, and Performance Traction
Management (PTM) mode. Each package is tuned or
calibrated individually, so, for instance, the operation is
not exactly the same between a Corvette Z06 and a
Corvette Stingray with the Z51 package. Vehicles
equipped with automatic and manual transmissions
have different eLSD calibrations, as do cars equipped
with different suspension and tire combinations.
A technician diagnosing a perceived fault with this
system MUST obtain very specific information from the
customer, and if a comparison vehicle is used, it is
imperative to obtain a car that is built with EXACTLY
the same options.

Version

Page 3

Wheel Slip Percentage
On the DIC screen for the eLSD system, there is also a
place for monitoring wheel slip. This can be viewed as
the white number at the bottom of the DIC page,
located on the 0 - 30% scale.
The purpose of this information is to notify the driver as
to how much rear wheel slip the vehicle is currently
experiencing. A few special notes on this system will
help prevent a misdiagnosis on the technician's part
when dealing with customer questions on this reading.
This graph actually has nothing to do with the eLSD
system. This is an independent calculation, and it is not
an indication of the slip inside the eLSD clutches.
The % of wheel slip is calculated by using the average
of the rear wheel slip as compared to the average of the
front wheel slip. This information is generally not
accurate below vehicle speeds of 20-30 mph (32-48
km/h), so when driving a slower speeds, the customer
may notice that the graph briefly maxes out at 30%.
This actually indicates normal operation. The reason for
this is as follows: because this calculation is displayed
as a percentage and not an actual value, if the front
wheels are traveling at 2 mph (3 km/h) and the rear
wheels are showing 3 mph (5 km/h), this indicates a
50% difference in speeds. As this graph is capped at
30%, the bar graph will "max out" in this type of
scenario. When traveling at these speeds, actual wheel
slip will not even be felt by the driver, even though it
appears drastic on the graph. This is simply the result
of the math behind the system.

2
Modified

Released March 04, 2019
October 13, 2020 – Added 2020-2021 Model Years for all Camaro models, added 2014
and 2020 Model Years to Corvette and updated the Involved Region or Country section.

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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