A/T - O/D OFF Lamp Flashing/DTC's 645/646/647/648
Article No.98-5-16
03/16/98
TRANSMISSION - 4R44E/4R55E - O/D OFF LAMP
FLASHING AND/OR DIAGNOSTIC TROUBLE CODES
(DTCS) 645, 646, 647, 648 STORED IN MEMORY
LIGHT TRUCK:
1995 EXPLORER
This TSB article is being republished in its entirety to update the Service Procedure.
CALIBRATION:
5-58B-R10, 5-58R-R10
WARNING:
THIS MODIFICATION IS AUTHORIZED ONLY FOR THE LISTED ENGINE. PERFORMING THIS MODIFICATION ON OTHER ENGINE CALIBRATIONS IS UNAUTHORIZED AND COULD CREATE LIABILITY UNDER APPLICABLE FEDERAL OR LOCAL LAWS.
ISSUE:
Some vehicles may experience a flashing "O/D OFF" lamp and/or the following Diagnostic Trouble Codes (DTCs) may occur: 645, 646, 647, 648. This may be caused by a damaged intermediate and/or overdrive servo piston seal, faulty Throttle Position (TP) sensor wiring or a concern with the transmission control strategy.
ACTION:
Follow the diagnostic procedures listed in the 1995 Explorer Service Manual and the following text for details.
Service all non-transmission DTCs and concerns first.
Service all transmission DTCs and concerns except for DTCs 645, 646, 647, 648.
For the above DTCs, follow TSB 97-17-24 making sure that the Electronic Pressure Control (EPC) solenoid is functional, transmission bands are adjusted properly, and the servos are not damaged.
Check the TP sensor wiring, wiring crimps, and perform a wiggle test.
If after checking the transmission and TP wiring no problems were identified, verify the vehicle has the latest level calibration. If it does not, replace the Powertrain Control Module (PCM). Refer to the PCM Application Chart for correct PCM usage.
Obtain an Authorized Modification Decal (FPS 8262 - obtainable through DOES II, 25/pkg) and list the date, dealer number, and summary of modifications performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.
PART NUMBER PART NAME
F5PZ-12A650-BRA Powertrain Control Module (PCM)
F5PZ-12A650-BSA Powertrain Control Module (PCM)
OTHER APPLICABLE ARTICLES: 95-19-12, 97-17-24
SUPERSEDES: 98-3-21
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage
OPERATION DESCRIPTION TIME
980516A Replace Powertrain Control 0.3 Hr.
Module (PCM)
DEALER CODING
CONDITION
BASIC PART NO. CODE
12A650 42
OASIS CODES: 206000, 501000, 504000