20-FL-004H

GROUP
FUEL SYSTEM
DATE
Technical Service Bulletin
SUBJECT:
MAY, 2020
NUMBER
20-FL-004H
MODEL(S)
ELANTRA (AD/ADA)
PALISADE (LX2)
SANTA FE (TM)
SONATA (DN8)
IDLE STOP & GO SYSTEM OPERATION, DIAGNOSTIC AND
BATTERY SENSOR RECALIBRATION PROCEDURE
This bulletin supersedes TSB 19-FL-002H to include additional models, and ISG system
diagnostics and requirements.
Description: This bulletin describes the Idle Stop and Go (ISG) system operation, diagnostic and
battery sensor recalibration procedure. Refer to applicable Shop Manual and Owner’s Manual for
additional information.
Applicable Vehicles: Elantra (AD/ADA), Palisade (LX2), Santa Fe (TM) and Sonata (DN8) vehicles
equipped with Idle Stop and Go (ISG) System
Note: Normal Warranty Applies
System Operation:
When the vehicle comes to a stop after brake pedal is depressed, the ISG system automatically and
temporarily shuts down the engine to improve fuel efficiency and reduce exhaust gas emissions. The
ISG system then restarts the engine when the brake pedal is released or the accelerator pedal is
depressed (if Auto Hold feature is equipped and activated).
The ISG system is active by default whenever the ignition is cycled to start the vehicle. To deactivate
the system, press the ISG OFF button.
Some Notable Prerequisites for ISG System Activation:






Battery has a 70% or above State of Charge
(SOC)
Shift lever is in DRIVE or NEUTRAL
Driver’s seatbelt is fastened
Driver’s door and the hood are closed
Brake vacuum pressure is adequate
Vehicle is not on a steep slope






Outside temperature is between 14 ~ 95oF
Engine coolant temperature is over 86oF
Air Conditioning system is not in high load or
demand
Steering wheel is turned less than 180 degrees
System is not in the diagnostic mode
No related diagnostic trouble codes
NOTICE


The ISG system will not be activated until all prerequisites are satisfied. If not
satisfied, the orange color Auto Stop symbol is illuminated in the instrument cluster
when the vehicle is stopped, and the “ISG OFF” button indicator illuminates or flashes
depending on ISG system version.
Vehicle speed must reach 5 MPH again for the ISG to activate after the previous stop.
Circulate To: General Manager, Service Manager, Parts Manager, Warranty Manager, Service
Advisors, Technicians, Body Shop Manager, Fleet Repair
SUBJECT:
IDLE STOP & GO SYSTEM OPERATION, DIAGNOSTIC AND
BATTERY SENSOR RECALIBRATION PROCEDURE
ISG System Operation Illustrations
1. Vehicle is moving.
2. Shift lever is in DRIVE.
Brake pedal is released.
3. Engine is running.
4. Driver brakes until vehicle is
stationary.
5. Shift lever is in DRIVE.
Brake pedal is pressed.
6. Engine stops running.
Green color Auto Stop
symbol illuminates in the
instrument cluster.
7. Driver wants to continue
moving.
8. Shift lever is in DRIVE.
Brake pedal is released.
9. Engine restarts and running.
Auto Stop symbol goes out.
TSB #: 20-FL-004H
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SUBJECT:
IDLE STOP & GO SYSTEM OPERATION, DIAGNOSTIC AND
BATTERY SENSOR RECALIBRATION PROCEDURE
Idle Stop and Go System Illuminations and Conditions
Auto Stop symbol illuminated
in green color
 ISG activated
 Engine stopped
Auto Stop symbol illuminated
in yellow color
 ISG prerequisites unsatisfied
 Engine running
ISG OFF button illuminated
 ISG prerequisites unsatisfied
 Idle Stop deactivated
 Battery sensor is recalibrating
 Engine running
Auto Stop symbol flashing in
green color
 ISG automatically restarted
 Engine running
Auto Stop symbol flashing in
yellow color
 ISG system malfunction
 Engine running
ISG OFF button flashing
 Battery cable or sensor was
recently disconnected
 Battery sensor is recalibrating
 Engine stopped
Situations ISG May Abort and Engine Automatically Restart:
 The vehicle is shifted to PARK or REVERSE when the brake pedal is depressed or Auto Hold is
activated
 The battery State of Charge (SOC) is below 70% threshold limit or the battery is weak
 The brake vacuum pressure is low
 The climate control system blower fan speed is set above the 6th position with air condition ON
 A certain period of time has elapsed with air condition ON
 The defroster is activated
 The driver door is opened or the driver seat belt is unfastened when the brake pedal is
depressed or Auto Hold is activated
 The Electronic Parking Brake (EPB) is pressed when Auto Hold is activated (if EPB is equipped)
TSB #: 20-FL-004H
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IDLE STOP & GO SYSTEM OPERATION, DIAGNOSTIC AND
BATTERY SENSOR RECALIBRATION PROCEDURE
SUBJECT:
!
WARNING


When the engine is in Auto Stop mode, the engine may restart on its own.
Never work the engine when the ignition is in “ON” or “ACC” position as the
engine may restart without warning.
Before leaving the vehicle or checking the engine compartment, stop the engine
by pushing/turning the ignition switch to the OFF position, and remove the key(s)
from the vehicle.

ISG System Diagnostics:
1. Turn the ignition key to the ON position or
press the Start-Stop Button two times
without depressing the brake pedal.
Connect a GDS Mobile VCI-II to the vehicle
data link connector.
2. Select “Data Analysis” within the GDS app.
TSB #: 20-FL-004H
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SUBJECT:
IDLE STOP & GO SYSTEM OPERATION, DIAGNOSTIC AND
BATTERY SENSOR RECALIBRATION PROCEDURE
3. Select “Engine”.
4. Scroll down the data analysis page and look
for Battery Voltage, SOC & SOH and ISG
parameters.
Quick Tips:
Click on the forward arrow ( > ) next to
“Actuation Test”. Then click “Group” and
select the desired data group to view
corresponding data.
 Select Alternator Management
System (AMS) group for battery
related data
 Select Idle Stop and Go (ISG) group
for ISG related data
TSB #: 20-FL-004H
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SUBJECT:
IDLE STOP & GO SYSTEM OPERATION, DIAGNOSTIC AND
BATTERY SENSOR RECALIBRATION PROCEDURE
5. Review all ISG parameters and compare the
parameters with a properly operating vehicle
(if in doubt).
Inspect any ISG data parameter that is
different from the properly operating vehicle
and make appropriate correction(s).
Follow the Shop Manual for additional
information.
6. Review all battery parameters, and compare
the parameters with a properly operating
vehicle (if in doubt).
Ensure State of Charge of Battery (SOC)
and State of Health of Battery (SOH) fields
display a percentage value.
7. If SOC or SOH displays “Checking” instead
of a percentage value, perform the battery
sensor recalibration procedure outlined on
Page #7 of this TSB.
8. Evaluate the ISG system operation when
SOC, SOH and all ISG operation
prerequisites are satisfied.
TSB #: 20-FL-004H
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SUBJECT:
IDLE STOP & GO SYSTEM OPERATION, DIAGNOSTIC AND
BATTERY SENSOR RECALIBRATION PROCEDURE
NOTICE




ISG does not activate if the Battery SOC is below 70%.
Charge the battery above 70% SOC level before conducting further ISG system
diagnosis.
 Idle charging – Idle the engine with headlights ON and monitor SOC value
with GDS (recommended procedure)
 Charge with a Battery Charger (if a battery cable was disconnected from
the terminal, battery sensor may need recalibration)
If the ISG system is working properly when the battery SOC is above 70% level,
inform the customer of the ISG system prerequisites and Battery SOC
requirements for ISG Operation. Refer to the Owner’s Manual for additional
information.
Battery may not get adequate charging when driving short distances and
frequent stop & go situations.
NOTICE


The battery should only be replaced if testing with either GR8 or Cadex battery
tester resulted in “Replace Battery”.
Battery replacement warranty submission without a “Replace Battery” printed
ticket along with associated warranty code will likely result in warranty charge
back.
Battery Sensor
 The battery sensor which is mounted on battery negative (-) terminal transmits battery voltage,
current, and temperature information to the Engine Control Module (ECM).
 The ISG system utilizes Battery State of Charge (SOC), Battery State of Health (SOH) and other
battery data generated by battery sensor.
 The battery sensor requires approximately 4 hours of continuous connection with a battery to
generate stabilized data.
 If any battery cable or battery sensor was disconnected from the battery or the battery was
recharged, perform the battery sensor recalibration procedure located below after finishing any
repair work.
Battery Sensor Recalibration Procedure:
 Switch the ignition "ON" and "OFF" one time.
 Park the vehicle for a minimum of 4 hours with the hood and all doors closed.
 Verify that battery SOC and SOH data are displayed.
TSB #: 20-FL-004H
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