19NA210

Bulletin No.:
Service Bulletin
Date:
19-NA-210
October, 2019
TECHNICAL
Subject:
Diagnostic Aid – EV Range Loss on Bolt EV
Brand:
Model:
Chevrolet
Bolt EV
Model Year:
VIN:
from
to
from
to
2017
2020
All
All
Engine:
Transmission:
All
All
Involved Region or Country
North America, South Korea, Middle East, Brazil
Condition
Some customers may comment on the EV range estimate to be lower than desired when
the battery pack is fully charged. This estimate is always displayed while driving, which
makes it highly visible to the driver. Some customers may describe the condition as not
being able to fully charge the vehicle.
Cause
The cause of the condition may be that the EV range estimate will change because it
accounts for current climate conditions, driving history, and internal battery factors while
attempting to be as accurate as possible.
Service Procedure
Chevrolet wants customers to have confidence in the
EV range of the Bolt EV. This bulletin will help
summarize four categories that could be causing a
reduced EV range estimate. Refer to the new
Copyright 2019 General Motors LLC. All Rights Reserved.
procedure in SI, Hybrid/EV High Voltage Battery
Reduced Range Analysis, for a step-by-step procedure
with full detail. A new limited-use labor operation code
was created to use for this diagnosis when a physical
battery repair is not required.
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October, 2019
Bulletin No.: 19-NA-210
5420681
Figure 1: Instrument Cluster showing a full charge and
less than EPA label range or the Canada EnerGuide
label range.
The EV range estimate is analogous to the fuel range
estimate on a traditional vehicle. Customers may be
more sensitive to EV range fluctuations due to EV
range anxiety and their commitment to the technology.
Category 1 – Defective Individual Battery Cell
Unique to the Bolt EV and not available on other GM
products, the vehicle will lower the available EV range
based on the individual battery cell with the lowest state
of charge. This helps prevent a large voltage drop in a
defective cell, but it does not set a diagnostic code or a
Service Vehicle Soon light indicating that remedial
action is being taken by the Hybrid/EV Propulsion
Control Module #2. The only indication to the driver is a
reduced EV range estimate. Follow the Hybrid/EV High
Voltage Battery Reduced Range Analysis procedure in
SI to determine if this is the reason for the customer’s
range loss and replace the appropriate battery section,
if needed. Note the state of charge variation % on the
repair order.
Category 2 – Outside Temperature, Cabin
Temperature, Terrain and Technique
Seasonal variation and driving history will impact the
EV range estimate. The Bolt EV stores eight months of
historical data for four individual factors which are now
accessible in GDS2 under the Energy Usage History
Data screen under the HPCM2 module. Follow the
Hybrid/EV High Voltage Battery Reduced Range
Analysis in SI to determine if this is the reason for the
customer’s range loss. The 2017 and 2018 model
years display this data as a unitless score. Beginning in
the 2019 model year, this data is displayed in units of
distance impact. The average score from each of the
last eight months is available to show which factor, if
any, has changed over time. History 1 is the average
from the last 30 days. History 8 is from eight months
Bulletin No.: 19-NA-210
October, 2019
Page 3
ago. This historic vehicle data, along with driving tips to
maximize range in the SI procedure, may be printed out
to share with the customer.
5420684
Figure 2: Example Energy History Data from GDS2 on
a 2020 Bolt EV where History 1 shows a better than
expected range over the last 30 days
An independent study by AAA found that all electric
vehicles have significant range loss during winter
months. If desired, refer to the AAA study at the
following link for details: https://newsroom.aaa.com/
2019/02/cold-weather-reduces-electric-vehicle-range/
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October, 2019
Bulletin No.: 19-NA-210
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Figure 3: Miles of winter impact on a 2019 Bolt EV with
an outside temperature of −8°C (18°F).
Electric vehicles, even in mild climates such as
California, can have several miles of seasonal range
variation. Encourage the customer to watch these four
factors in the energy display on the center screen. The
data in this customer display will reset to zero on each
full charge event. Note on the repair order if one of
these factors from historical GDS2 data is the primary
reason for the loss of EV range along with the actual
Total Score _ History 1 value. Perform an EV Range
Reset as needed, following the instructions in the SI
procedure.
Note: Do not perform a battery capacity reset in GDS2
for a category 2 range loss.
Category 3 – Target Charge Level or Hilltop Reserve
The Bolt EV has a feature to limit the maximum state of
charge in the charging settings on the center display.
Any setting less than maximum will reduce available
EV range. For 2017 and 2018, this was known as
Hilltop Reserve. Note the setting for this category on
the repair order.
Bulletin No.: 19-NA-210
October, 2019
Page 5
5420686
Figure 4: Target Charge Level screen on a 2019 or
newer Bolt EV
Category 4 – Battery Pack Capacity Degradation
Like all batteries, the amount of energy the battery pack
can store will decrease with time and distance driven.
In North America, if the battery loses more than 40% of
its capacity during the eight year or 100,000 mile /
160,000 km EV warranty period, the pack may be
replaced for the customer. Follow the Hybrid/EV High
Voltage Battery Reduced Range Analysis in SI to
determine if this is the reason for the customer’s range
loss. As demonstrated by the first three categories, the
EV range estimate is impacted by much more than
pack capacity. Share with the customer that the battery
pack was evaluated for replacement and provide the
present capacity value from GDS2 and at what capacity
the pack will be replaced under warranty (refer to SI).
Note the pack capacity on the repair order, in
Amp-hours.
Conclusion
As Bolt EVs age, there may be a combination of factors
contributing to reduced range, such as use of a
non-OEM replacement tire (shown by a negative
Terrain score), combined with some pack capacity loss,
and cabin heater use (shown by a negative Climate
Settings score). The important task is to differentiate
items which require battery repair versus which items
are normal for the vehicle. The goal is for the customer
to understand why a repair was or was not performed
on the vehicle for an EV range concern.
Version
1
Modified
Released October 13, 2019
Additional SI Keywords: battery, range, EV, electric,
charge, charging, charges, low, reduced, 4T, capacity,
degradation, mileage, miles, distance, estimate,
anxiety, score, energy, voltage
Warranty Information
If the battery pack requires repair (Category 1 or 4), use
the associated labor operation for a pack or section
replacement with appropriate diagnosis time to
complete the SI reduced range analysis procedure.
If no physical repair is needed (Category 2, 3, or 4), use
the new labor operation code below and provide the
following on the repair order from the GDS2 Energy
Usage History Data and charge settings:
Category 1 – Cell State of Charge Variation
%: __________
Category 2 – Total Score – History 1 value:
___________ primarily caused by ____________
Category 3 – Target Charge Level or Hilltop Reserve
Setting: (Maximum Charge or Less than Maximum)
Category 4 – Battery Pack Capacity
(Ah): ____________
The following labor operation is covered under the EV
propulsion warranty with coverage code (V) in North
America.
Labor
Operation
5031139
Description
Labor Time
Hybrid/EV High Voltage
Battery Reduced Range
Analysis
0.9 hr*
*The November 1 update of the Labor Time Guide will
contain this change.