Reprogramming File Availability For DTC P0137 And Improvement Of Engine Rpm (Idle) Drop Condition (11-160-15)

Publication date: 2015-09-14
Reference number: 11-160-15

REPROGRAMMING FILE AVAILABILITY FOR DTC P0137 AND IMPROVEMENT OF ENGINE RPM (IDLE) DROP CONDITION

TECHNICAL SERVICE BULLETIN

Reference Number(s): 11-160-15, Date of Issue: September 14, 2015

SUBARU:

2015 Legacy & Outback

APPLICABILITY

2015MY Legacy & Outback, 2.5L and 3.6L Models

INTRODUCTION

This bulletin announces availability of reprogramming files to optimize the ECM for DTC P0137. These files will also address customer concerns of engine idle RPM drop after a hot engine restart on 2.5L models and when shifting from reverse to drive after a cold start on 3.6L models.

PACK FILE APPLICABILITY

MODEL YEAR/MODEL

EMISSION SPEC.

PAK FILE NAME

NEW ECM PART NUMBER

OLD ECM PART NUMBER

TRANSMISSION

NEW CID NUMBER

2015MY Legacy & Outback 2.5L

CAL⁽¹⁾

22765AF36D.pak

22765AF36D

22765AF36A

EB4G400C

EB4GA00C

22765AF36B

EB4G401C

22765AF36C

EB4G600C

CAL⁽¹⁾

22765AK16B.pak

22765AK16B

22765AK16A

N/A

EB4GA00c

FED

22765AF35D.pak

22765AF35D

22765AF35A, 35B & 35C

EB4GA00B

2015MY 3.6L

FED

22765AF45C.pak

22765AF45C

22765AF45A & 45B

DB4GA00D

⁽¹⁾	IMPORTANT NOTE: On these CAL Emission Specification vehicles, verify the current (OLD) CID number first then use the CID Search function in FlashWrite to determine which new reprogramming file is applicable to the vehicle being repaired.

SERVICE PROCEDURE / INFORMATION

IMPORTANT: Before beginning this reprogramming procedure, if P0137 is stored, the Freeze-Frame Data (FFD) MUST be reviewed first to eliminate a faulty O2 sensor as the root cause of the DTC. In the case of an RPM drop, although this condition will in most cases not cause the Check Engine light to come on, the ECM will likely store a DTC P1603 and the corresponding FFD. In either of these cases, the stored FFD MUST be reviewed and compared to the information provided below to rule out other possible causes of the stored DTC before installing any of these ECM updates. If your FFD looks very different from the examples outlined, then another cause is suspected. In that case, follow the appropriate troubleshooting in the applicable Service Manual to determine the cause.

P0137 INFORMATION

P0137 Scenario #1

Item	History3	History	History1	Detect	Unit
Engine Speed	2256	2255	2237	2237	rpm
Time Since Engine Start	1815	1815	1816	1816	sec
Vehicle Speed	58	58	58	58	MPH
Calculated load value	0.0	0.0	0.0	0.0	%
Coolant Temp.	176	176	176	176	°F

Item	History3	History	History1	Detect	Unit
Engine Speed	848	825	864	871	rpm
Time Since Engine Start	53	54	54	55	sec
Vehicle Speed	3	2	2	1	MPH
Calculated load value	28.6	27.8	30.2	30.2	%
Coolant Temp.	151	151	151	151	°F

The O2 sensor temperature is controlled by the ECM and maintained using a heater to keep it within a certain range. The heater works with predetermined voltages depending on driving conditions. When exhaust gases heat the sensor, less heater voltage is required. The purpose of heater voltage control is to avoid overheating the sensor at the same time it is being heated by exhaust gas. The ECM judges the O2 sensor has been activated and therefore reduces the heater voltage. In Scenario #1 the sensor cools down due to the long fuel cut condition caused by the long downhill (coasting condition, 0% Calculated load value) shown in the first SSM screenshot above. Scenario #1 also shows the DTC setting at about 30 minutes since engine start although the second FFD example shows the DTC setting at about 1 minute after engine start.

Scenario #2 shows this DTC can set at almost any time during the first 1 to 40 minutes after engine start under varying load, temperature and vehicle speed conditions. A "cold" O2 sensor will not work properly and eventually cause the CEL to illuminate. In this update, the ECM logic has been optimized accordingly to improve control of O2 sensor heater voltage.

IDLE DROP (DTC P1603) INFORMATION

FOR 2.5L MODELS:

DTC P1603 will be stored (with FFD) whenever the engine speed drops below 300 RPM for 48 milliseconds (ms) BUT, it will not cause the CEL to illuminate. The FFD stored should be used to help determine a cause for the condition. In Scenario #3 on page 3, the engine is fully warmed up and was restarted after a (approximate) 10-minute hot-soak. The FFD shows P1603 set within 5 seconds after restarting the hot engine with "0" vehicle speed and shifter in Neutral. The idle was OK at first but the rpm drop occurred shortly thereafter. The cause of the rpm drop is fuel vaporization in the fuel rails due to high under-hood temperatures. In this update, the ECM logic has been optimized providing an improved fuel mixture to overcome the effects of vaporization.

Item	History3	History2	History1	Detect	Unit
Engine Speed	1489	1001	378	286	rpm
Time Since Engine Start	3	4	4	4	sec
IG OFF Elapsed Time	900	900	900	900	sec
Coolant Temp.	203	203	203	203	°F
Vehicle Speed	0	0	0	0	MPH
At drive status	NEUT	NEUT	NEUT	NEUT

There is also a PID called "IG OFF Elapsed Time" which can be used to determine the length of the hot soak prior to setting the DTC.

FOR 3.6L MODELS:

In some cases, an rpm drop can occur when shifting from Reverse to Drive after a cold start. The FFD in Scenario #4 shows P1603 set within about 15 seconds after starting the cold engine with a very low vehicle speed and the shifter in Drive. Under these conditions, a slight increase of throttle opening is needed to compensate for the additional engine torque requirement needed after the shift into Drive. The ECM logic has been optimized to make this compensation occur sooner after the shift into Drive occurs thereby eliminating the rpm drop.

P1603 Scenario #4

Item	History3	History2	History1	Detect	Unit
Engine Speed	1422	1196	739	368	rpm
Time Since Engine Start	13	14	14	15	sec
Coolant Temp.	30	30	32	32	°F
Vehicle Speed	4	3	1	1	MPH
AT drive status	DRIVE	DRIVE	DRIVE	DRIVE

NOTE: SOA now highly recommends connecting the Midtronics GR8 Diagnostic Battery Charger to the vehicle and utilizing the Power Supply Mode feature anytime a vehicle control module is being reprogrammed. Once the GR8 is connected to the vehicle, as long as the battery is fully charged, it takes less than 3 minutes to boot-up the charger, select the Power Supply Mode, and have the battery voltage stabilized and ready for reprogramming.

VERY IMPORTANT: This information is applicable to the Midtronics GR8 Diagnostic Battery Charger ONLY . It does not apply to any other brand / type of "generic" battery charger whatsoever. ONLY the GR8 and its Power Supply Mode feature has been tested and approved by Subaru of America, Inc. (SOA).

If the GR8 indicates the vehicle's battery must be charged, charge the battery using the GR8 before proceeding to reprogram the vehicle while using the Power Supply Mode.
Control module failures as a result of 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 Basic New Car Limited and / or Emissions Warranty period, this repair may be submitted using the following claim information:

LABOR DESCRIPTION	LABOR OPERATION #	FAIL CODE	LABOR TIME
MFI OBDII ECM Reprogramming	A455-288	UPG-48	0.4

IMPORTANT: The NEW Calibration Identification number (CID) for any newly-installed programming (as confirmed from the actual control module AFTER installation) MUST be noted on the repair order as this information is required for claim submission.

NOTE: The pack 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 III software installed on your system. You can confirm if a later version is available by entering the CID listed in this bulletin into FlashWrite. If a newer CID is shown as available in FlashWrite, reprogram using that file.

REMINDER: 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 refer to STIS for the latest service information before performing any repairs.