Reprogramming File Availability For DTC P1603 And Rpm Drop During Acceleration (09-134-25)

Publication date: 2025-03-17
Reference number: 09-134-25

REPROGRAMMING FILE AVAILABILITY FOR DTC P1603 AND RPM DROP DURING ACCELERATION

TECHNICAL SERVICE BULLETIN

Reference Number(s): 09-134-25, Date of Issue: March 17, 2025

SUBARU:

2024-25 Impreza & Crosstrek

APPLICABILITY

2024-25MY Impreza & Crosstrek

INTRODUCTION

The Bulletin announces the availability of reprogramming files to optimize the Engine Control Module (ECM). These new files are designed to address cases where the ECM detects DTC P1603 (Engine Stall History) due to decreased engine revolutions per minute (RPM) during acceleration after a long idle period. The files optimize the evaporative purge control to prevent excessively rich conditions, which can cause a momentary decrease in RPM and the DTC to set.

PRODUCTION CHANGE INFORMATION

The reprogramming files have been incorporated into vehicle production as per the table below.

Model	Stating VIN
IMPREZA/CROSSTREK	SH239680

PFC FILE INFROMATION

MY	Model	Specification	File Description	Old Part Number	New CID
24	IMPREZA	2.0L NA CVT	22765AS713.PFC	22765AS710 22765AS711 22765AS712	XE1Z100fx0G
	IMPREZA	2.0L NA CVT AGS	22765AS813.PFC	22765AS810 22765AS811 22765AS812	XE1Z100dx0G
	CROSSTREK	2.0L NA CVT	22765AS793.PFC	22765AS790 22765AS791 22765AS792	XE1Z100ex0G
	CROSSTREK	2.0L NA CVT AGS	22765AS783.PFC	22765AS780 22765AS781 22765AS782	XE1Z100cx0G
25	IMPREZA	2.0L NA CVT	22765AU901.PFC	22765AU900	XE1Z100kA0G
	IMPREZA	2.0L NA CVT AGS	22765AU891.PFC	22765AU890	XE1Z100fA0G
	CROSSTREK	2.0L NA CVT	22765AU921.PFC	22765AU920	XE1Z100hA0G
	CROSSTREK	2.0L NA CVT AGS	22765AU911.PFC	22765AU910	XE1Z100eA0G

SERVICE PROCEDURE/INFORMATION

REMINDER: Customer satisfaction and retention starts with performing quality repairs.

Reprogram the ECU following the normal SSM5-R procedure. Detailed information regarding the SSM5-R reprograming procedures can be found in TSB 14-28-21R NEW SOFTWARE REPROGRAMMING PROCEDURES/SSM5-R .

Subaru of America, Inc. (SOA) highly recommends utilizing either the Subaru Midtronics DCA-8000 Dynamic Diagnostic Charging System or the Subaru Midtronics GR8-1100 Diagnostic Battery Charger to the vehicle and utilizing the Power Supply Mode feature anytime a vehicle control module is being reprogrammed. Once the Midtronics charger is connected to the vehicle, if the battery is fully charged, it takes less than three (3) minutes to boot-up the charger, select the Power Supply Mode, and have the battery voltage stabilized and ready for reprogramming.

NOTE:

For instructions on using the Power Supply Mode, reference the applicable User Manual for the Midtronics DCA-8000 Dynamic Diagnostic Charging System and the Midtronics GR8-1100 Diagnostic Battery Charger on STIS
Confirm all electrical loads such as lights, audio, HVAC, seat heaters, and rear defroster are all switched OFF before setting up the charger for Power Supply Mode.
Select the correct battery type (Enhanced Flooded, Flooded, Gel, AGM or AGM Spiral).
Input the CCA which matches the vehicle's battery.
NOTE: OE and replacement batteries have different CCA ratings. Always confirm the battery's CCA rating before proceeding.
If using a DCA-8000 Dynamic Diagnostic Charging System, set the power supply voltage to 13.5 Volts.
DO NOT connect the DST-i or DST-010 until the Power Supply mode function has completed its battery test mode and the Charging Voltage has dropped to and shows a steady 13.5 Volts on the display.
Once Power Supply Mode reaches a steady 13.5 Volts, connect the DST-i or DST-010 to the OBD connector and proceed with initiating the normal SSM5-R reprogramming process.
Amperage will fluctuate based upon the vehicle's demand for power.
NOTE: If the voltage rises beyond 14 Volts while programming is in process, the procedure will abort. This can indicate a need to test or charge the vehicle battery before any further attempt at programming is made.
ALWAYS set the power supply voltage to 13.5 Volts when using Power Supply Mode. NEVER turn the ignition switch on when charging at voltages 15 Volts or higher.

REMINDER: If the DCA-8000 or GR8-1100 indicates the vehicle's battery must be charged, charge the battery fully before proceeding to reprogram the vehicle while using the Power Supply Mode.

NOTE: Control module failures resulting from battery discharge during reprogramming are not a matter for warranty. Should any DTCs reset after the reprogramming update is performed, diagnose per the procedure outlined in the applicable Service Manual.

WARRANTY/CLAIM INFORMATION

For vehicles within the Federal Emissions Extended Defect Warranty period or covered by a Subaru Added Security Classic or Gold plan, this repair may be submitted using the following claim information:

Labor Description	Labor Operation #	Fail Code	Labor Time
ECM REPROGRAMMING FOR DTC P1603	A453-186	UPG-48	.4H

IMPORTANT: Always note the original Calibration Identification number (CID)/ROMID the vehicle came in with on the repair order before reprogramming and, make sure to list the NEW CID/ROMID for any newly installed programming (as confirmed from the actual control module AFTER installation). The NEW CID/ROMID MUST also be noted on the repair order as this information is required for entry in the Miscellaneous Detail field during claim submission. These numbers can be read using SSM5-R.

NOTE: The pfc file listings provided in this bulletin are the latest available at the time of publishing. Updates are often released thereafter without revision to the original bulletin. For this reason, it is critical to always have the latest version of Select Monitor software installed on your system. You can confirm if a later version is available by entering the CID listed in this bulletin into SSM5-R. If a newer CID is shown as available in SSM5-R, reprogram using that file.

IMPORTANT REMINDERS:

SOA strongly discourages the printing and/or local storage of service information as previously released information and electronic publications may be updated at any time.
Always check for any open recalls or campaigns anytime a vehicle is in for servicing.
Always refer to STIS for the latest service information before performing any repairs.