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Subaru Service and Technical Support Line Newsletter

SPECIAL EDITION
Articles Contained
in this Issue
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CODE ARTICLE...................................................................PAGE
(20) SUBARU STRONG HYBRID
ELECTIC VEHICLE........................................... 1
(20) PHEV-SHEV-BEV............................................ 2
(09) CHANGE TO THE FUEL SYSTEM..................2-3
(15) HYBRID JACK INFORMATION......................... 3
(20) HIGH VOLTAGE BATTERY DOESN’T DISPLAY
FULL CHARGE................................................ 4
(15) HV BATTERY WON’T CHARGE IN NEUTRAL.... 5
(20) AUTO VEHICLE SHUT DOWN AND WHAT IT
MEANS TO “IDLE” IN A HYBRID.................... 6
(20) SPORT MODE DISABLES EV OPERATION....6-7
(15) WIRELESS CHARGER OPERATION-AM RADIO
STATIC........................................................7-8

20

SUBARU STRONG HYBRID ELECTRIC VEHICLE

We are excited for the arrival of the Subaru SHEV platform! The release
of the 2025 Forester SHEV brings with it a new powertrain layout and
efficiency better than any Subaru prior. As with any new product, there
will be many things to learn to be sure we understand how the vehicle
is designed to operate. Without a basic understanding of how something
should operate, it will be difficult to diagnose and repair a concern or even to
know if a condition is abnormal. Resources like the owner’s manual, TSB’s,
TRB’s and other training materials are an excellent source for this kind of
information. If you are unsure about how something should function and
can’t find published material regarding that system, comparing operation
against a like vehicle can be beneficial. In this Special Edition Techtip we
are going to highlight some characteristics of vehicle operation that are
normal.
Safety is a priority when working on any vehicle, and this is especially true
when working on HEV or EV vehicles due to the increased shock risk. These
vehicles should only be serviced and repaired by qualified technicians. Be
sure to follow all safety protocol based on the service manual, training, and
industry practices.

CAUTION: VEHICLE SERVICING PERFORMED BY UNTRAINED PERSONS
COULD RESULT IN SERIOUS INJURY TO THOSE PERSONS OR TO OTHERS.

The Subaru TechTIPS newsletter is intended for use by professional Technicians ONLY. Articles are written
to inform those Technicians of conditions that may occur in some vehicles, or to provide information
that could assist in the proper servicing of the vehicle. Properly trained Technicians have the equipment,
tools, safety instructions, and know-how to do the job correctly and safely. If a condition is described,
DO NOT assume that your vehicle has or will have that condition. Impreza, Legacy, Justy, Loyale,
Outback, Forester, Subaru SVX, WRX, WRX STI, Baja, Tribeca, BRZ, XV Crosstrek, Ascent, Crosstrek
Hybrid, Solterra and “Quality Driven” are Registered Trademarks.

Special Edition TechTIPS

SUBARU OF AMERICA, INC. IS
ISO 14001 COMPLIANT
ISO 14001 is the international standard for excellence in Environmental Management Systems.
Please recycle or dispose of automotive products
in a manner that is friendly to our environment
and in accordance with all local, state and federal laws and regulations.

Page 1 of 8

20

PHEV-SHEV-BEV

The automotive industry is full of acronyms, and it is important to know what they mean. So, what do
the acronyms MHEV, SHEV, PHEV and BEV stand for? And more importantly, what does this mean for
vehicle operation?
MHEV stands for ‘Mild Hybrid Electric Vehicle’. MHEV’s typically have smaller batteries than any other EV
and use the electric motor to assist the internal combustion engine (ICE). The 2014-16 Crosstrek Hybrid is
a MHEV. SHEV stands for ‘Series Hybrid Electric Vehicle’. SHEV’s have larger, more powerful batteries than
MHEV’s. SHEV’s have two electric motors and prioritize using the electric motor to propel the vehicle instead
of the ICE. The 2025 Forester Hybrid is a SHEV. PHEV stands for ‘Plugin Hybrid Electric Vehicle’. PHEV’s can
charge the battery using an external power source. PHEV’s are also a type of SHEV. The 2019-22 Crosstrek
Hybrid is a PHEV. BEV stands for ‘Battery Electric Vehicle’. BEV’s do not have an ICE and use only energy
from the battery to propel the vehicle. The Solterra is a BEV.

Something else to consider is some of the names used for components may vary depending on the
model. For instance, the component that converts energy from the high voltage battery may have different
terminology. For both Hybrid Crosstrek models, this component is called the Inverter or Inverter with
converter assembly. For Solterra, this component is called the Electric Converter Unit (ESU). For the SHEV,
this component is called the Power Control Unit.

09

CHANGES TO THE FUEL SYSTEM

Re-fueling the 2025 Forester SHEV is a little different than most other models. In order to re-fuel the Forester
SHEV, the fuel door release switch must be pressed first. When the fuel door release switch is pressed, a
component called the ‘Electric Vent Solenoid’ will activate. The purpose of this solenoid is to relieve pressure in
the fuel tank. This is needed because the EVAP system is not able to purge accumulated gasoline vapors when
the internal combustion engine (ICE) is not operating. The rest of the EVAP components used and operation of
these components is similar when compared to a non-hybrid counterpart. The electric vent solenoid was first
utilized on the 2019-22 MY Crosstrek Hybrid.

Continued on the next page

Special Edition TechTIPS

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09

CHANGES TO THE FUEL SYSTEM (CONTINUED)

EVAP pressure equalization, between the atmosphere and
fuel tank pressure, and solenoid operation can be heard and
is considered normal operation. Due to the pressure adjustment
the fuel door may take 10 seconds to open.
Note: The fuel door will not open under the following conditions:
•

While the vehicle is driving

•

When the select lever is not in the “P” position

•

When there is a malfunction in the fuel system

Complete fueling within 30 minutes after pressing the fuel door
release switch. After 30 minutes the vehicle auto stop function
activates and fuel cannot be added to the tank. If this occurs,
press the fuel door release switch again.

15

HYBRID JACK INFORMATION

The 2025 Forester SHEV does not come equipped with a jack to lift the vehicle. However, the
owner’s manual states that a jack can be ordered. The jack can also be stowed under the driver’s
front seat. If a customer would like to purchase a jack, please use these part numbers:
No.

Part Number

Description

1

97032SL000

Jack

2

97034SL000

Label Jack

3

97063FL000

Band Jack

Continued on the next page
Special Edition TechTIPS

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20

HIGH VOLTAGE BATTERY DOESN’T DISPLAY FULL CHARGE

You may receive a customer concern that the high voltage battery state of charge (SOC) rarely or never
displays a full charge. This is considered normal.
Some key points to highlight:
•

The remaining amount of the high voltage battery state of charge is automatically controlled to
improve fuel efficiency, it increases or decreases depending on the driving conditions.

•

It is not unusual that the maximum battery state of charge (SOC) may not be reached except on
consecutive downhill roads.

•

If the vehicle is not used for a long time, the high voltage battery will discharge on its own (selfdischarge) and reduce the remaining high voltage battery level.

•

To maintain the high voltage battery in good condition, drive the vehicle at least once every 2 to
3 months for at least 30 minutes or 10 miles. Without proper battery maintenance the battery life
may be shortened.

•

Even if there is a sufficient amount of electricity remaining in the high voltage battery, EV driving
may be cancelled, and both the gasoline engine and the electric motor are used depending on the
situation.

Continued on the next page
Special Edition TechTIPS

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20

HV BATTERY WON’T CHARGE IN NEUTRAL

An important operational characteristic to be aware of is that the high voltage battery will not charge
while the transmission is in neutral. Generally, this should not be a concern. However, if the high voltage
battery state of charge (SOC) is low and there is a high electrical load, this could discharge the 12-volt
battery and affect vehicle operation. The Forester SHEV does not have an alternator and uses the high
voltage battery and DC/DC converter to charge the 12-volt battery. Using an automated carwash typically
requires the select lever to be placed in neutral. Although extremely unlikely, this is a scenario that could
cause this concern. If a customer presents a vehicle with a discharged 12v battery concern that cannot
be duplicated, be sure to interview the customer about this vehicle characteristic.
If a customer reports this has occurred, be sure to review the control operation history in the hybrid
powertrain control module for more information. Information about control operation history for this
system can be found in the service manual here: Diagnostics> Hybrid Powertrain Control (Diagnostics)>
Work Support> List.

If the vehicle is left in neutral for an extended period of time especially when vehicle is under high electrical
load, the following messages may occur.

Continued on the next page
Special Edition TechTIPS

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20

AUTO VEHICLE SHUT DOWN AND WHAT IT MEANS TO ‘IDLE’ IN A HYBRID

A somewhat new function to the Subaru lineup is called ‘Automatic Vehicle Shut Down’. This feature
can be found on models other than the Forester SHEV. Automatic vehicle shut down will turn off the
ignition switch if the select lever is in park for 30 minutes. If the customer is not aware of this function,
they may leave the vehicle on for an extended period of time intending to operate the heat or air
conditioning and return to find the vehicle has powered down. This function can be disabled but will
be enabled when the key is cycled. If you receive a customer concern that the vehicle shut off by itself,
be sure to interview the customer about this function. Keep in mind that idling in a hybrid vehicle is
different than an internal combustion engine (ICE) vehicle idling because there is no audible noise while
the vehicle is in EV mode.

20

SPORT MODE DISABLES EV OPERATION

In the owner’s manual in the “Hybrid System” chapter, listed are many of the conditions that will prevent
EV mode. This means the internal combustion engine (ICE) will run. We also wanted to point out that
using Sport mode or manual mode will also cause the ICE to stay running. If a customer presents a
vehicle with a concern that the ICE was running continuously, be sure to interview the customer about
this condition.

Continued on the next page
Special Edition TechTIPS

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20

SPORT MODE DISABLES EV OPERATION (CONTINUED)

15

WIRELESS CHARGER OPERATION-AM RADIO STATIC

AM Radio Noise During SHEV Operation and Wireless Phone Charging
Electromagnetic interference (EMI) is an electronic system disturbance caused by an electromagnetic
interaction with an external source. EMI can cause electronics to operate poorly, malfunction, or stop
working altogether. It can arise due to both natural and human-made sources. In this instance this is
witnessed during hybrid system operation and wireless phone charging and there is no guarantee that
interference will not occur.
The hybrid system generates weak natural frequencies while operating. As a result, the AM radio may
experience static. This occurs under specific conditions such as starting and stopping, driving at very
low speeds (around 2MPH), and high-torque driving like rapid acceleration.
Similar noise can occur during wireless phone charging. You may be able to reduce the noise by
changing the wireless charging frequency. This can be done by pressing and holding the power switch
to turn on the system. After a certain amount of time, the indicator light will flash orange twice to
indicate the frequency switch.

Special Edition TechTIPS

Continued on the next page

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15

WIRELESS CHARGER OPERATION-AM RADIO STATIC (CONTINUED)

Wireless Charging and Quick Charge CAUTION - The wireless power receiver can affect some implanted or other electrical medical devices.
If you use a cardiac pacemaker, ventricular pacing pulse generator, cardioverter-defibrillator, or a
similar device, consult with your physician before using the wireless charger.
The wireless charger quick charge function was introduced with 2024 Impreza and Crosstrek and is
now equipped on the 2025 Forester.
To change modes, while in normal mode press the power switch three times to change to the quickcharging mode. The indicator light will change from orange to alternating green and orange when the
wireless charger switches to the quick-charging mode. Quick charge mode ends when charging is
complete. See the owner manual for compatible devices.
Some things to note: If the phone is not properly aligned with the charging coil or if the access key is
not detected the wireless charger will not charge. To prevent discharging the 12V battery, do not use
the wireless charger for long periods of time when the hybrid system is stopped. Lastly do not charge
a device in dusty conditions.

*1: No power is output for charging when the wireless charger is in standby mode. Even if metal
objects are placed on the charging tray in this state, they will not overheat.
*2: For some mobile devices, the indicator light remains orange even after charging is complete.

Special Edition TechTIPS

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