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Home >> Ford >> 2000 >> Excursion 7.3 F, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 202 (Driveline System - General Information) >> Diagnosis And Testing >> Differential Electronic Module (DEM) >> Pinpoint Tests >> Pinpoint Test A: No Communication With the DEM >> Testing
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Pinpoint Test A: No Communication With the DEM: Testing

WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.
  1. A1 CHECK SMART JUNCTION BOX (SJB) MINI-FUSE 19 (10A) 
    • Check SJB mini-fuse 19 (10A).
    • Is the fuse okay? 
    • Yes  : GO to A2.
    • No  : INSTALL a new fuse. CHECK the system for normal operation.
  2. A2 CHECK CIRCUIT 972 (BK/WH) FOR VOLTAGE 
    • Disconnect: DEM C.
    • Key in ON position.
    • Measure the voltage between DEM 2081-1, circuit 972 (BK/WH) harness side and ground.
      Fig 1: Measuring Voltage Between Harness Side And Ground
      G03988366Courtesy of FORD MOTOR CO.
    • Is the voltage between 9 and 18 volts? 
    • Yes  : GO to A3.
    • No  : REPAIR the circuits as necessary. TEST the system for normal operation.
  3. A3 CHECK CIRCUIT 570a (BK) FOR AN OPEN 
    • Key in OFF position.
    • Measure the resistance between DEM 2081-2, circuit 570a (BK) harness side and ground.
      Fig 2: Measuring Resistance Between Harness Side And Ground
      G03988367Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    • Yes  : CHECK the module communication network. REFER to MODULE COMMUNICATIONS NETWORK .
    • No  : REPAIR the circuit. TEST the system for normal operation.
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