Brakes - ABS Lamp ON/DTC's C1235/C1236/C1237 Set

Article No.
03-26-3

01/12/04

BRAKES - ABS LAMP ILLUMINATED AND DTC
C1235, C1236, C1237 - VEHICLES WITH
DIFFERENTIAL - MOUNTED REAR WHEEL SPEED
SENSOR

FORD:
2002-2004 EXPLORER

LINCOLN:
20Q3-2004 AVIATOR

MERCURY:
2002-2004 MOUNTAINEER

ISSUE
Some vehicles may exhibit an Anti-Lock Brake System (ABS) warning lamp illuminated with Diagnostic Trouble Codes (DTCs) C1235, C1236 and/or C1237 (Wheel Speed RR Input Signal Missing/Wheel Speed LR Input Signal Missing/Rear Wheel Speed Sensor Output Failure) stored in memory. This may be due to an intermittently functioning differential-mounted Rear Wheel Speed Sensor.

ACTION
To service, refer to the following diagnostic and repair procedure.

NOTE
THIS TSB ONLY APPLIES TO VEHICLES WITH DTCS C1235, C1236 AND/OR C1237. FOR ALL OTHER DTC'S, REFER TO THE APPROPRIATE WORKSHOP MANUAL.

NOTE
THIS TSB DOES NOT APPLY TO VEHICLES EQUIPPED WITH ADVANCETRAC (STABILITY ASSIST / IVD).

SERVICE PROCEDURE

1. Retrieve Continuous ABS DTC(s).

2. If C1235, C1236 and/or C1237 are present, turn ignition OFF and replace the differential-mounted Rear Wheel Speed Sensor.

a. Raise vehicle on hoist so that the bottom of the rear differential is at head level.





b. Stand slightly in front of the rear differential pinion flange, facing the rear of the vehicle (Figure 1).

c. Reach up and over the passenger side of the differential housing to access sensor.

d. Remove the hold-down bolt and remove sensor from differential housing (3/8" socket).

e. Unlatch red locking tab on the top of the electrical connector by sliding it away from the sensor, then release connector latch and disconnect connector from sensor.

f. Install new sensor and torque hold-down bolt to 27 N.m (20 lb-ft).

g. Connect the electrical connector to the sensor.

NOTE
IT IS NO LONGER NECESSARY TO APPLY F8AZ-19G208-AA GREASE TO THE ELECTRICAL CONNECTOR AS PREVIOUSLY RECOMMENDED.

3. Clear Continuous ABS DTC(s).

4. Verify repair.

NOTE
THE ABS SYSTEM CONFIRMS REAR WHEEL SPEED SENSOR SIGNAL INPUT BASED ON SEVERAL WHEEL REVOLUTIONS ABOVE 24 KM/H (15 MPH). DRIVE VEHICLE FOR AT LEAST 75 FEET AT OR ABOVE 15 MPH. IF WHEEL SPEED SIGNAL INPUT IS MISSING THE ABS LIGHT WILL ILLUMINATE.





Parts Block

OTHER APPLICABLE ARTICLES: NONE

WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage

OPERATION DESCRIPTION TIME

032603A Replace The Differential 0.5 Hr.
Mount Rear Wheel Speed
Sensor (Includes Time To
Check For Codes Replace
Sensor And Clear Codes)

DEALER CODING
CONDITION
BASIC PART NO. CODE
9E731 42





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