LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2002 >> Taurus SES, 3.0 S >> Repair and Diagnosis >> External Pages >> Different car >> Section 194 (Engine Controls - Self-Diagnostics - 6.0L (99P F450/550) Diesel) >> System Tests >> Test X: Exhaust Pressure Sensor >> Testing

Test X: Exhaust Pressure Sensor: Testing

WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, 2003 Ford Excursion, and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION: The Powertrain Control Module (PCM) harness connectors must be properly seated and the connector latch properly attached to eliminate possible driveability concerns or a no-start condition. Installing PCM connectors on an angle may cause a bad connection, misdiagnosis and damaged components. Install the connector on where the lever pivots and seats itself. Apply light pressure to get the connector into position on the PCM lever to fully seat the connector.
NOTE: When the PCM engine harness connector is disconnected additional DTCs will be set. All DTCs must be cleared before returning the vehicle to service.

  1. 1) Preliminary Diagnosis For DTCS P0470, P0471, P0472, P0473 Or P0478

    Perform a visual inspection. Connect the scan tool. Retrieve and record all DTCs. Record the freeze frame data. Clear the DTCs. Perform the KOEO ON-DEMAND SELF-TEST  under QUICK TEST. Perform the KOER ON-DEMAND SELF-TEST  under QUICK TEST. Are DTCs P0470, P0471, P0472, P0473 or P0478 present? If yes, proceed as follows:
    • For KOEO DTC P0470, go to next step.
    • For continuous DTC P0470, go to step  4).
    • For DTC P0471, go to step  6).
    • For DTC P0472 or P0478, go to step  10).
    • For DTC P0473, go to step  15).

    If no, unable to duplicate condition. Check for loose connections, damaged or corroded terminals or pins. Wiggle harness attempting to recreate fault. Repair as necessary. See TROUBLE SHOOTING - NO CODES - 6.0L DIESEL article if a driveability concern exists.

  2. 2) DTC P0470

    Possible causes are:
    • EP sensor.
    • SIG RTN circuit open.
    • PCM.

    Key on, engine off. Access the EBP PID. Is the EBP PID less than 18.5 psi (127 kPa)? If yes, clear the DTC. Repeat the KOEO ON-DEMAND SELF-TEST  under QUICK TEST. If DTC P0470 is present again, install a new PCM. If no, go to next step.

  3. 3) Check The Signal Return Circuit

    Key off. Disconnect the EP sensor. Disconnect the PCM engine harness connector C1381C. Measure the resistance between the EP sensor SIG RTN circuit terminal "A", harness side and the PCM engine harness connector C1381C terminal No. 25, harness side. See Figure and CONTROL MODULE CONNECTOR IDENTIFICATION . Is the resistance less than 5 ohms? If yes, install a new EP sensor. If no, repair the circuit.

  4. 4) Continuous DTC P0470

    Possible causes are:
    • EP sensor.
    • PCM.

    Access the EBP PID. Observe the EBP PID while carrying out the following: Grasp the vehicle harness close to the EP sensor connector. Wiggle and shake the vehicle harness while working toward the PCM. Key off. Does the EBP PID reading fluctuate? If yes, isolate the intermittent connection. Repair as necessary. If no, go to next step.

  5. 5) Inspect The EP Sensor & PCM Connectors

    Disconnect the EP sensor. Inspect the EP sensor connector and terminals. Inspect the PCM connectors. Are all the connections okay? If yes, unable to duplicate condition. See TROUBLE SHOOTING - NO CODES - 6.0L DIESEL article if a driveability concern exists. If no, repair as necessary.

  6. 6) DTC P0471

    Possible causes are:
    • EP sensor.
    • EP sensor supply tube plugged or restricted.
    • PCM.

    Perform the KOEO ON-DEMAND SELF-TEST  under QUICK TEST. If other DTCs are present, repair before continuing. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . Access the EBP PID. Road test the vehicle performing hard accelerations while monitoring the EBP PID. Is the EBP increase greater than 25 psi with EBP device on? If yes, unable to duplicate condition. Check for loose connections, damaged or corroded pins. Wiggle harness attempting to recreate fault. See TROUBLE SHOOTING - NO CODES - DIESEL - 6.0L article if driveability concerns exist. If no, go to next step.

  7. 7) Inspect For Exhaust Leaks

    Inspect the turbo pipe, crossover tubes and exhaust manifolds for leaks. Are any exhaust leaks present? If yes, repair the exhaust leak. If no, go to next step.

  8. 8) Check The EP Sensor Supply Tube

    Inspect the EP sensor supply tube. Is the EP sensor tube restricted or plugged? If yes, install a new EP sensor tube. If no, go to next step.

  9. 9) EP Sensor Check

    Disconnect the EP sensor. Install the ICP/EBP Adapter Cable (D94T-50-A) or equivalent between the EP sensor and vehicle harness. Key on, engine running. Measure the voltage between the EP signal circuit and ground on ICP/EBP Adapter Cable (D94T-50-A). Accelerate the engine to WOT several times. Is the voltage greater than 1.35 volts during acceleration? If yes, clear the DTC. Repeat the KOEO ON-DEMAND SELF-TEST  under QUICK TEST. If DTC P0471 is present again, install a new PCM. If no, install a new EP sensor.

  10. 10) DTC P0472 Or P0478

    Possible causes are:
    • EP sensor signal circuit open.
    • Biased sensor.
    • EP sensor signal circuit shorted to ground.
    • VREF circuit open.
    • EP sensor.
    • PCM.

    Key off. Disconnect the EP sensor. Key on, engine off. Measure the voltage between the EP sensor VREF circuit terminal "B", harness side and ground. See Figure. Is the voltage between 4.5 and 5.5 volts? If yes, go to next step. If no, repair the circuit.

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 10) to step 12). No test procedures have been omitted.

  11. 12) Check The EP Sensor

    Access the EBP PID. Connect a fused jumper wire (5-amp) between the EP sensor VREF circuit terminal "B", harness side and the EP sensor signal circuit terminal "C", harness side. Is the EBP PID voltage approximately 4.5 to 5.5 volts? If yes, install a new EP sensor. If no, go to next step.

  12. 13) Check The Signal Circuit For An Open

    Key off. Disconnect the PCM engine harness connector C1381C. Measure the resistance between the EP sensor signal circuit terminal "C", harness side and the PCM engine harness connector C1381C terminal No 27, harness side. See CONTROL MODULE CONNECTOR IDENTIFICATION . Is the resistance less than 5 ohms? If yes, go to next step. If no, repair the circuit.

  13. 14) Check The Signal Circuit For A Short To Ground

    Measure the resistance between the EP sensor signal circuit terminal "C", harness side and ground. Is the resistance greater than 10,000 ohms? If yes, for DTC P0472, install a new PCM. For DTC P0478, inspect the exhaust system for restrictions. If the exhaust system is okay, go to next step. If no, repair the circuit.

  14. 15) DTC P0473

    Possible causes are:
    • EP signal shorted to voltage.
    • SIG RTN circuit open.
    • EP sensor.
    • PCM.

    Induce the opposite DTC. Disconnect the EP sensor. Key on, engine off. Perform the KOEO ON-DEMAND SELF-TEST  under QUICK TEST. Is DTC P0472 present? If yes, install a new EP sensor. If no, go to next step.

  15. 16) Check The EP Sensor Signal Circuit For A Short To Voltage

    Key off. Disconnect the PCM engine harness connector C1381C. Key on, engine off. Measure the voltage between the EP sensor signal circuit terminal "C", harness side and ground. Is any voltage indicated? If yes, repair the circuit. If no, go to next step.

  16. 17) Check The EP Sensor SIG RTN Circuit For An Open

    Key off. Measure the resistance between the EP sensor SIG RTN circuit terminal "A", harness side and the PCM engine harness connector C1381C terminal No. 25, harness side. Is the resistance less than 5 ohms? If yes, install a new PCM. If no, repair the circuit.
scientia non olet · About LEMON Manuals