Ford Mustang (1999-2004) Service Manual: Inspection and Verification

1. Verify the customer concern by operating the wiper/washer system.

2. Visually inspect for obvious signs of mechanical and electrical damage.

Visual Inspection Chart

Mechanical Electrical
  • Hoses to windshield washer pump
  • Wiper linkage
  • CJB Fuse 39 (5A)
  • CJB Fuse 26 (30A)
  • Wiring harness
  • Loose or corroded connector(s)
  • Relays
  • Motors
  • Multifunction switch
  • GEM

3. If the concern remains after the inspection, connect the diagnostic tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the diagnostic tool menu. If diagnostic tool does not communicate with the vehicle:

  • Check that the program card is correctly installed.
  • Check the connections to the vehicle.
  • Check the ignition switch position.

4. If diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool manual.

5. Carry out the DATA LINK DIAGNOSTIC TEST. If diagnostic tool responds with:

  • CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to Section.
  • NO RESPONSE/NOT EQUIPPED for GEM, go to Pinpoint Test A.
  • SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out self-test diagnostics for the GEM.

6. If the DTCs retrieved are related to the concern, go to GEM Diagnostic Trouble Code (DTC) Index to continue diagnostics.

7. If no DTCs related to the concern are retrieved, proceed to Symptom Chart to continue diagnostics.

GEM Diagnostic Trouble Code (DTC) Index

GEM Diagnostic Trouble Code (DTC) Index

GEM Diagnostic Trouble Code (DTC) Index

Symptom Chart

Condition Possible Sources Action
  • No communication with the generic electronic module
  • CJB Fuse 39 (5A).
  • Circuitry.
  •  GEM.
  • GO to Pinpoint Test A .
  • The wipers are inoperative
  • CJB Fuse 26 (30A).
  • Ignition switch.
  • Circuitry.
  • GEM.
  • Multifunction switch (13K359).
  • Wiper ON/OFF relay.
  • Wiper HIGH/LOW relay.
  • Wiper motor.
  • GO to Pinpoint Test B .
  • The wipers stay on continuously
  • Circuitry.
  • GEM.
  • Multifunction switch.
  • Wiper ON/OFF relay.
  • Wiper HIGH/LOW relay.
  • Wiper motor.
  • GO to Pinpoint Test B .
  • The HIGH and LOW wiper speeds do not operate correctly
  • Circuitry.
  • GEM.
  • Multifunction switch.
  • Wiper HIGH/LOW relay.
  • Wiper motor.
  • DTC B1434.
  • GO to Pinpoint Test B
  • The intermittent wiper mode does not operate correctly
  • Circuitry.
  • GEM.
  • Multifunction switch.
  • Wiper motor.
  • GO to Pinpoint Test B
  • The washer pump is inoperative
  • CJB Fuse 26 (30A).
  • Circuitry.
  • GEM.
  • Multifunction switch.
  • Washer pump relay.
  • Washer pump.
  • Ignition switch.
  • GO to Pinpoint Test C .
  • The low wiper speed does not operate correctly
  • Circuitry.
  • Multifunction switch.
  • Wiper HIGH/LOW relay.
  • Wiper motor.
  • GEM.
  • DTC B1473.
  • DTC B1434.
  • GO to Pinpoint Test B .
    Principles of Operation
    Multifunction Wipers The front wiper/washer feature controls the speed of the front windshield wipers and the amount of washer fluid sprayed on the front windshield when requested by the cus ...

    Pinpoint Tests
    CAUTION: Before removing and installing the GEM or its connectors, disconnect the battery. Failure to follow this caution will result in the GEM storing many erroneous DTCs and it may exhibit errati ...

    Other materials:

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