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Home >> Ford >> 2001 >> Mustang Base, 2D Convertible, Automatic >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls Self-Diagnostics - EEC-V - CNG & Gasoline - System Tests KD - Z >> Test KD: Electric Exhaust Gas RECIRCULATION >> Diagnostic Aids

Diagnostic Aids

Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used to diagnose the following:

Fig 1: Identifying Electric Exhaust Gas Recirculation System Circuits
G00035633Courtesy of FORD MOTOR CO.
NOTE: If DTC P0403 was set due to an intermittent condition, perform wiggle test on wiring harness and connectors while performing the following test procedures.

  1. 1) KOER & Continuous Memory DTC P0403: Check EEGR Stepper Motor Connection To Harness

    This DTC indicates a malfunction has been detected in one or more of 4 EEGR stepper motor coils or circuits, and/or PCM is detecting an open, short to VPWR or GND. Possible causes for this fault are:
    • EEGR Stepper Motor Windings Open
    • EEGR Stepper Motor Connector Not Properly Seated
    • Open Or Short To VPWR Or GND In Circuit Between PCM To EEGR Stepper Motor
    • Open Or Short Circuit In PCM
    • Short To VPWR Or GND In EEGR Stepper Motor

    Ensure EEGR stepper motor harness connector is fully seated. Repair as necessary. If connector is okay, go to next step.

  2. 2) Check For B+ Voltage At EEGR Stepper Motor Harness Connector

    Turn ignition switch to ON position. Using a DVOM, measure voltage by backprobing between ground and EEGR stepper motor harness connector terminals No. 2 and 5. See Fig 1. If both voltage measurements are more than 10.5 volts, go to next step. If either voltage measurement is 10.5 volts or less, check for blown fuse No. 41 (20-amp) in battery junction box. Battery junction box is located in left rear of engine compartment. If fuse is blown, repair short to ground in B+ circuit to EEGR stepper motor. If fuse is okay, repair open in B+ circuit between battery junction box and appropriate EEGR stepper motor terminal. See WIRING DIAGRAMS article.

  3. 3) Check EEGR Stepper Motor Circuits For Shorts To Ground In Harness

    Turn ignition switch to OFF position. Disconnect PCM connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance between negative battery terminal and all EGRM circuits at specified PCM harness connector terminals. See EEGR STEPPER MOTOR HARNESS CIRCUIT IDENTIFICATION  table. If each resistance measurement is more than 10 k/ohms, go to next step. If any resistance measurement is 10 k/ohms or less, repair short to ground in appropriate EGRM circuit.
    EEGR STEPPER MOTOR HARNESS CIRCUIT IDENTIFICATION (1)

    EEGR Stepper Motor Harness Connector Terminal No. (Wire Color) (2) PCM Harness Connector Terminal No.
    1 (Tan/Red) 98
    3 (Gray/Red) 72
    4 (Violet/Orange) 73
    6 (Dark Green) 99
    (1) For EEGR stepper motor harness connector terminal identification, see Fig 1.
    (2) EEGR stepper motor harness connector terminals No. 2 and 5 (Light Blue/Orange wires) are fused B+ circuits. See SYSTEMS WIRING DIAGRAMS article.

  4. 4) Check EEGR Stepper Motor Circuits For Opens In Harness

    Ensure ignition switch is turned to OFF position. Using a DVOM, measure resistance of all EGRM circuits between specified EEGR stepper motor and PCM harness connector terminals. See EEGR STEPPER MOTOR HARNESS CIRCUIT IDENTIFICATION  table. If all resistance measurements are less than 5 ohms, go to next step. If any resistance measurement is 5 ohms or more, repair open in appropriate EGRM circuit.

  5. 5) Check EEGR Stepper Motor Circuits For Shorts To Each Other In Harness

    Ensure ignition switch is turned to OFF position. Using a DVOM, measure resistance between PCM harness connector terminal No. 72 and terminals No. 73, 98 and 99. Also, measure resistance between PCM harness connector terminal No. 73 and terminals No. 98 and 99. See Fig 1. If each resistance measurement is more than 10 k/ohms, go to next step. If any resistance measurement is 10 k/ohms or less, repair short between appropriate EGRM circuits.

  6. 6) Check EEGR Stepper Motor Circuits For Shorts To VPWR In Harness

    Connect PCM connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between ground and EEGR stepper motor harness connector terminals No. 1, 3, 4 and 6. If all voltage measurements are less than .1 volt, go to next step. If any voltage measurement is .1 volt or more, repair short to VPWR in appropriate EGRM circuit.

  7. 7) Check EEGR Stepper Motor Windings For Open Or Short To VPWR

    Turn ignition switch to OFF position. Ensure EEGR stepper motor is disconnected. Using a DVOM, measure resistance between EEGR stepper motor terminal No. 2 (VPWR) and terminals No. 1 (EGRM4) and No. 3 (EGRM3). Also, measure resistance between EEGR stepper motor terminal No. 5 (VPWR) and terminals No. 4 (EGRM1) and No. 6 (EGRM2). See Fig 1. Each resistance measurement should be 20-24 ohms. If all resistance measurements are within specification, go to next step. If any resistance measurement is not within specification, replace EEGR stepper motor.

  8. 8) Check EEGR Stepper Motor Windings For Short To Ground

    Ensure ignition switch is turned to OFF position. Disconnect PCM connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance between negative battery terminal and EEGR stepper motor harness connector terminals No. 1, 3, 4 and 6. If resistance is more than 10 k/ohms, replace PCM. If resistance is 10 k/ohms or less, replace EEGR stepper motor.
    9. NOTE: If DTCs P0102, P0103, P0107, P0108, P1100 or P1101 were also present, service them prior to continuing with this test step.
    NOTE: During the following procedure, DTCs may be set in PCM. After performing test, clear DTCs and repeat QUICK TEST procedures to ensure all EEC-V systems are working properly and DTCs are no longer present.

  9. 9) DTC P0400 & P1408: Check For Mechanically Stuck EEGR Stepper Motor
    These DTCs indicate KOER ON-DEMAND SELF-TEST failed due to measured EGR flow falling below or exceeding required calibration. Possible causes are:
    • EEGR Valve Stuck Closed Or Open
    • Carbon Build-Up In EEGR Valve Seat Area

    Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, access OUTPUT TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. Select EGRMDSD and MAP PIDs. Start engine and allow it to reach normal operating temperature. Raise engine speed to 1000-1200 RPM to prevent engine from stalling. Engine RPM must remain steady during test. Using scan tool, introduce EGR function in small increments (about 8-12 steps), while monitoring MAP PID. MAP PID value should increase as EGR function is introduced with scan tool. If MAP PID does not increase as specified, replace EEGR stepper motor. If MAP PID value increases as specified, fault cannot be duplicated at this time. Ensure MAP connector is seated correctly and vacuum source is not blocked.

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