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Home >> Fiat >> 2013 >> 500e >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Electric Vehicle Control Unit (EVCU) Module - DTCS P1139 To U1487 - 500E >> Diagnosis And Testing >> P1C76-Reverse Switch 1 Circuit Low >> Diagnostic Test
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Diagnostic Test

  1. CHECK IF DTC IS CURRENT 
    1. Using the scan tool, read EVCU DTCs.
    2. Record the Environmental Data and any DTCs.
    3. Clear DTCs.
    4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    5. Read EVCU DTCs.

      Did the DTC reset?

      Yes 

      • Go To  2

      No 

  2. CHECK THE REVERSE LOW SIDE SWITCH (1) OPERATION 
    1. Using the scan tool, and the ePRND Typical Switch Voltage table, operate the Reverse Switch and note the voltage for Not Pressed and Pressed.

      Is the Reverse Low Side Switch (1) lower than the voltage listed in the table for either switch position?

      Yes 

      • Go To  3

      No 

      • Using the schematics as a guide, check the Electric Vehicle Control Unit (EVCU) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the EVCU in accordance with the Service Information. Refer to UNIT, ELECTRIC VEHICLE CONTROL (EVCU), REMOVAL .
      • Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  3. CHECK THE (T402) REVERSE LOW SIDE SWITCH (1) FOR AN OPEN 
    1. Turn the ignition off. Remove the key from the Ignition Switch, close doors and allow the EVCU to shut down.
      NOTE:

      Allow up to two minutes for the EVCU to shut down. Opening the vehicle door will interrupt the shut down process.

    2. Disconnect the EVCU C1 harness connector.
    3. Disconnect the ePRND harness connector.
    4. Measure the resistance of the (T402) Reverse Low Side Switch (1) circuit between the appropriate terminal of the EVCU C1 harness connector and the ePRND harness connector.

      Is the resistance of the (T402) Reverse Low Side Switch (1) circuit above 5.0 Ohms?

      Yes 

      • Repair the (T402) Reverse Low Side Switch (1) circuit for an open.
      • Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .

      No 

      • Go To  4
  4. CHECK THE (T402) REVERSE LOW SIDE SWITCH (1) FOR A SHORT TO GROUND 
    1. Measure the resistance of the (T402) Reverse Low Side Switch (1) circuit between ground and the appropriate terminal of the EVCU C1 harness connector.

      Is the resistance below 100k Ohms?

      Yes 

      • Repair the (T402) Reverse Low Side Switch (1) circuit for a short to ground.
      • Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .

      No 

      • Using the schematics as a guide, check the ePRND pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the ePRND in accordance with the Service Information. Refer to SWITCH, ELECTRIC SHIFTER, REMOVAL .
      • Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .
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