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Home >> Ford >> 2000 >> Taurus LX, 3.0 2, AX4N >> Repair and Diagnosis >> External Pages >> Different car >> Section 857 (Automatic Transmission - 4R70E/4R75E - F150 & Mark LT) >> Diagnostic Tests >> Pinpoint Tests - OSC Equipped Vehicle >> Pinpoint Tests >> Pinpoint Test D: Electrical Pressure Control (EPC) Solenoid

Pinpoint Test D: Electrical Pressure Control (EPC) Solenoid

WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Refer to the Transmission Internal Harness illustration Transmission Connector Layouts  in this article.
NOTE: Read and record all DTCs. All digital transmission range (TR) sensor and vehicle speed sensor (VSS) DTCs must be repaired before entering Output State Control (OSC).
  1. D1 ELECTRONIC DIAGNOSTICS 
    • Key in OFF position.
    • Select PARK.
    • Check to make sure the transmission harness connector is fully seated, pins are fully engaged in the connector and in good condition before proceeding.
    • Connect the diagnostic tool.
    • Key in ON position.
    • Enter the following diagnostic mode on the diagnostic tool: Diagnostic Data Link
    • Enter the following diagnostic mode on the diagnostic tool: PCM
    • Enter the following diagnostic mode on the diagnostic tool: Active Command Modes
    • Enter the following diagnostic mode on the diagnostic tool: Output State Control (OSC)
    • Enter the following diagnostic mode on the diagnostic tool: Trans-Bench Mode
    • Does the vehicle enter the Trans-Bench Mode? 
    1. YES  : Go to  D2.
    2. NO  : REPEAT procedure to ENTER Trans-Bench Mode. If vehicle did not enter OSC, REFER to the INTRODUCTION - GASOLINE ENGINES article for diagnosis of PCM.
  2. D2 SOLENOID FUNCTIONAL TEST 
    • Install 2,060 kPa (300 psi) pressure gauge into electronic pressure control (EPC) tap.
    • Monitor pressure gauge.
    • Enter the following diagnostic mode on the diagnostic tool: Parameter; EPC
    • Select value - 15, 30, 45, 60, 70 or 90 psi.
    • Press "SEND".
    • Select another value "0-90 psi".
    • Press "SEND".
    • Enter the following diagnostic mode on the diagnostic tool: XXX
    • Press "SEND".
    • Does the pressure reading match the commanded pressure? 
    1. YES  : CLEAR DTCs. REPEAT OBD Tests.
    2. NO  : Go to  D3.
  3. D3 CHECK FOR VOLTAGE 
    • Disconnect: Transmission Harness Connector
    • Key in ON position.
    • Measure the voltage on pin 6 at the transmission harness connector to chassis ground.
      • Fig 1: Measuring Voltage On Pin 6 At Transmission Harness Connector To Chassis Ground
      GF0003458Courtesy of FORD MOTOR CO.
    • Is the voltage less than 5 volts? 
    1. YES  : Go to  D4.
    2. NO  : REPAIR the circuit.
  4. D4 CHECK FOR BATTERY VOLTAGE 
    • Remove transmission fluid pan.
    • Visually inspect the lead frame connectors for damage.
    • Key in ON position.
    • Measure the voltage with positive lead to VPWR solenoid pin and negative lead to a good ground.
      • Fig 2: Measuring Voltage With Positive Lead To VPWR Solenoid Pin And Negative Lead To Ground
      GF0003459Courtesy of FORD MOTOR CO.
    • Is voltage greater than 10 volts? 
    1. YES  : Go to  D5.
    2. NO  : REPAIR the circuit. CLEAR the DTCs. REPEAT the OBD Tests.
  5. D5 ELECTRICAL SIGNAL CHECK 
    • Measure the voltage with positive lead connected to VPWR solenoid pin and connect negative lead to the signal pin of the EPC solenoid.
      Fig 3: Measuring Voltage With Positive Lead Connected To VPWR Solenoid Pin
      GF0003460Courtesy of FORD MOTOR CO.
    • Turn the solenoids ON and OFF, while monitoring the voltage reading, solenoid state on the scan tool (ON and OFF), listen for the solenoid to activate (click).
    • Enter the following diagnostic mode on the diagnostic tool: Trans-Bench Mode
    • Enter the following diagnostic mode on the diagnostic tool: Parameter EPC
    • Select a value "0-90 psi".
    • Press "SEND".
    • Select another value "0-90 psi".
    • Press "SEND".
    • Enter the following diagnostic mode on the diagnostic tool: XXX
    • Press "SEND".
    • Does the voltage and solenoid state change? 
    1. YES  : Go to  D6.
    2. NO  : CHECK for open or short circuit in harness or PCM.
  6. D6 CHECK MOLDED LEAD FRAME SOLENOID CONNECTIONS 
    • Key in OFF position.
    • Disconnect: Molded Lead Frame
    • Inspect the molded lead frame for damage.
    • Using the special tool, check all molded lead frame solenoid connections.
      • Fig 4: Checking Molded Lead Frame Connector Pins Using Special Tool
      GF0003437Courtesy of FORD MOTOR CO.
    • Does the special tool go easily through the molded lead frame connector pins? 
    1. YES  : INSTALL a new molded lead frame. Go to  D7 .
    2. NO  : Go to  D7.
  7. D7 CHECK SOLENOID RESISTANCE AT SOLENOID 
    • Measure the resistance of the EPC solenoid.
      • Fig 5: Measuring Resistance Of EPC Solenoid
      GF0003461Courtesy of FORD MOTOR CO.
    • Is the resistance between 2.48 and 5.66 ohms? 
    1. YES  : Go to  D8.
    2. NO  : INSTALL a new solenoid. CLEAR the DTCs. REPEAT the OBD Tests.
  8. D8 CHECK SOLENOID FOR SHORT TO GROUND  
    • Check for continuity between engine GROUND and the EPC solenoid terminals with ohmmeter or other low current tester (less than 200 milliamps). Connection should show infinite resistance (no continuity).
      • Fig 6: Checking Continuity Between Engine GROUND And EPC Solenoid Terminals
      GF0003462Courtesy of FORD MOTOR CO.
    • Is there continuity? 
    1. YES  : INSTALL a new solenoid. CLEAR the DTCs. REPEAT the OBD Tests.
    2. NO  : REFER to Diagnosis By Symptom  in this article for diagnosis of pressure concerns.
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