Engine Control Module (ECM) Reprogramming (WWF-89)

ENGINE CONTROL MODULE (ECM) REPROGRAMMING

SERVICE CAMPAIGN BULLETIN

INTRODUCTION

Subaru of America, Inc. (SOA) has determined that some affected vehicles listed below may require ECM reprogramming. The ECM logic for the air/fuel ratio circuit may not be broad enough to accept the signal parameters of the A/F ratio sensor. Should the A/F ratio sensor signal repeatedly fluctuate beyond the parameters of the ECM logic, the CHECK ENGINE warning light / Malfunction Indicator Lamp (MIL) will illuminate steadily while the engine is running, advising the driver of a malfunction and the need to seek repair service. Reprogramming the ECM will broaden the allowable A/F ratio signal parameters and correct this condition.

This condition is a software issue and has no impact on vehicle emissions or driveability.

This service program will involve reprogramming the ECM on affected vehicles.

AFFECTED VEHICLES

• 2000-01 MY Subaru Legacy and Outback with H4 engine and 4EAT transmission only. (Legacy and Outback vehicles with the H6 engine or  MT5 transmission are not  affected.)
• 2000-02 MY Impreza with MT5 or 4EAT. (Impreza WRX models are not  affected.)
• 2001-02 MY Forester with MT5 or 4EAT.

Affected vehicles are identified in the VIN range chart below.  NOTE: Prior to performing repairs, confirm coverage for potentially affected vehicles by using the Vehicle Coverage Inquiry in the Dealer Communication System (DCS).

MODEL			FROM	TO
Legacy  (1)	2000MY	Sedan Wagon Outback	Y7216796 Y7311191 Y7658510	Y7218478 Y7313778 Y7674127
	2001MY	Sedan Wagon Outback	17200013 17300038 17600009	17212059 17309150 17658747
Impreza (2)	2000MY	Coupe Sedan	Y(3)403351 Y(3)504668	Y(3)403888 Y(3)505796
	2001MY	Coupe Sedan	1(3)400001 1(3)500003	1(3)402563 1(3)503187
	2002MY	Sedan Wagon	2(3)500050 2(3)800021	2(3)504423 2(3)804023
Forester	2001MY		1(3)712940	1(3)769251
	2002MY		2(3)700001	2(3)705899
(1) Legacy and Outback vehicles with the H6 engine or  MT5 transmission are not  affected. (2) Impreza WRX models are not  affected. (3) Various characters may occupy this position of the VIN.

OWNER NOTIFICATION

SOA will prepare and mail an Owner Notification Letter to owners of affected vehicles on or around April 24, 2002.

A copy of the Owner Notification Letter is included at the end of this bulletin.

DEALER PROGRAM RESPONSIBILITY

Dealers are to promptly service all vehicles subject to this service program at no charge to the vehicle owner regardless of mileage, age of the vehicle, or ownership.

For affected vehicles sold after the date on the dealer's computer list, dealers are to contact those owners and provide them with a copy of the owner notification letter. They should also arrange to make the required correction according to the instructions in the service procedure section of this bulletin.

Dealers are also to promptly perform the applicable service procedures defined in this bulletin to correct all affected vehicles in their inventory (new, used, demo). Additionally, whenever a vehicle subject to this service program is taken into dealer new or used inventory, or is in the dealership for service, necessary steps should be taken to ensure the service program correction has been made before selling or releasing the vehicle.

SPECIAL TOOLS

Dealers will automatically be shipped the necessary special select monitor reprogramming cables and cartridges for this campaign at no charge. If additional reprogramming cables and cartridges are needed, please contact your District Service Operations Manager for ordering instructions.

Part numbers are as follows: 

Select Monitor Reprogramming Cable - 22775Z0C00 

Select Monitor Reprogramming Cartridge - 24082X0A54 

SERVICE PROCEDURE

Using the Select Monitor Reprogramming Cable, Part Number 22775Z0C00, connect the Select Monitor to the vehicle's Diagnostic Link Connector (DLC) located in the vehicle's lower left dash panel. Insert the appropriate "Diagnostic"  cartridge for the vehicle being serviced, and retrieve and record any diagnostic trouble codes previously stored in the ECM.

If no codes are found  , proceed to the "ECM REPROGRAMMING PRECAUTIONS  and ECM REPROGRAMMING INSTRUCTIONS " section of this bulletin.

If trouble codes are found  , refer to the following table for the correct repair procedure. Make any necessary repairs and clear all codes prior to reprogramming the ECM.

DIAGNOSTIC TROUBLE CODE	REPAIR PROCEDURE
No Codes	Reprogram the ECM.
P0133	Clear codes and reprogram the ECM
P0031, P0130 (or) P1133	Replace the Front Oxygen (A/F) Sensor (refer to the applicable service manual for replacement procedure), clear codes and reprogram the ECM.
Any other code or combination of codes not listed above.	Refer to applicable service manual for additional diagnostic procedures. After completing repairs, clear codes and reprogram the ECM.