4X4 System - Increased Steering Effort on Low Speed Turn
TSB 05-3-802/21/05
INCREASED TURNING EFFORT DURING LOW SPEED
SHARP TURNS - FALSE 4X4 ENGAGEMENT
FORD:
2004-2005 Explorer
MERCURY:
2004-2005 Mountaineer
This article supersedes TSB 04-26-08 to update the service procedure.
ISSUE
Some 2004-2005 Explorer/Mountaineer 4x4 vehicles may exhibit an increased effort while turning, during low speed sharp turning maneuvers. This condition may be caused by the 4x4 control module software or an issue with the differential mounted rear ABS sensor initializing improperly (results in a reading twice as high as actual speed). The binding caused by the 4x4 control module software tends to be momentary, while the binding caused by the ABS sensor tends to be intermiffent, but more continuous when occurring.
ACTION
Follow the appropriate Service Procedure based on vehicle build date and equipment level.
SERVICE PROCEDURE 1 - 2004-2005
Explorer/Mountaineer 4x4 Vehicles Built Before
12/13/2004
NOTE
THIS PROCEDURE DOES NOT APPLY TO AWD EXPLORER/MOUNTAINEER VEHICLES.
1. Verify the condition and monitor the transfer case clutch duty cycle PID (WDS PID: 4WDCPWMST (Units-%); NGS+ PID: PWM_DC1 (Units-%); NGS PID: PWM).
NOTE
MONITOR THE PID MULTIPLE TIMES TO VERIFY CONDITION. THE SCAN TOOL MAY MISS THE CLUTCH DUTY CYCLE SPIKE.
a. If the duty cycle NEVER reads over 60%, reprogram the 4x4 control module to the latest level after installing WDS release B35.2 Patch 3 or higher. The patch file containing this calibration can also be obtained at the website.
^ Select Module Programming from WDS menu.
^ Select 4x4 from listed modules and follow on-screen instructions.
b. If the duty cycle PID reads over 60% continue with normal vehicle diagnosis, unless the vehicle is an Explorer 4x4 equipped with ABS (only) built from 6/8/2004 through 8/12/2004, or has been serviced in the past with rear wheel speed sensor 4L24-9E731-BB (engineering part number stamped on the side). If the vehicle meets this criteria proceed to Service Procedure 2.
NOTE
THIS NEW CALIBRATION IS NOT INCLUDED IN THE B35 CD.
NOTE
THE 4X4 MODULE IS PHYSICALLY LOCATED IN THE PCM.
SERVICE PROCEDURE 2 - 2004 Explorer 4x4
Vehicles With ABS (Only) Built 6/8/2004 Through 8/12/2004 Or Previously Serviced With Engineering Part Number 4L24-9E731-BB
NOTE
THIS PROCEDURE DOES NOT APPLY TO AWD EXPLORERS, EXPLORERS WITH ADVANCE TRAC OR MOUNTAINEERS.
1. Verify the condition, checking for the following symptoms:
NOTE
SINCE THE PROBLEM IS INTERMITTENT THE VEHICLE MAY HAVE TO BE STARTED AND DRIVEN A FEW FEET MULTIPLE TIMES TO INITIATE AN INCORRECT REAR ABS WHEEL SPEED SENSOR CALIBRATION.
a. Transfer case clutch duty cycle PID reads
97% continuously when the bind occurs
(WDS PID: 4WDCPWMST (Units-%); NGS+
PID: PWM_DC1 (Units-%); NGS PID: PWM)
with 4x4 switch in Auto.
b. The ABS module may have diagnostic
trouble codes C1235, C1236 stored in
memory.
c. The rear wheel speed PID indicates twice
as high as the front wheel speed PIDs.
d. At very low speeds, the vehicle slows to a
stop if the steering wheel is at full turn, and
the accelerator is not depressed.
2. If the symptoms listed above are occurring, replace the differential mounted rear ABS sensor. If not, continue with normal vehicle diagnosis.
Parts Block
WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage And Emissions Warranty Coverage
OPERATION DESCRIPTION TIME
050308A 2004-2005 0.7 Hr.
Explorer/Mountaineer 4x4
Built Before 12/13/2004
Service Procedure One:
Reprogram The 4x4
Control Module (Includes
Time To Monitor PID, And
Road Test)
050308B 2004 Explorer 4x4 0.8 Hr.
Vehicles Built 6/8/2004
Through 8/12/2004 Service
Procedure Two: Replace
The Rear Wheel Speed
Sensor (Includes Time To
Monitor PID, And Road
Test)
DEALER CODING
CONDITION
BASIC PART NO. CODE
RECAL (LABOR OPERATION A) 04 (OP A)
9E731 (LABOR OPERATION B) 42 (OP B)
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