LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2000 >> Taurus LX, 3.0 2, AX4N >> Repair and Diagnosis >> External Pages >> Different car >> Section 11 (Engine Controls - Self-Diagnostics - EEC-V (Bi-Fuel)) >> System Tests (Bi-Fuel) >> Test U: SCP Invalid Or Missing Data >> Diagnostic Aids

Diagnostic Aids

WARNING: This page is about a different car, the 2000 Mercury Mystique, 2000 Ford Pickup, 2000 Ford F550 Super Duty, 2000 Ford F450 Super Duty, and 2000 Ford Contour. However, it is still accessible from the selected car via links, so may be relevant.

Enter this test only when all steps under QUICK TEST have been successfully completed and engine still does not start or if directed here from another test or chart. This test is only intended to diagnose:

NOTE: During bi-fuel diagnostics, intermittent failures are possible. Perform wiggle test and tap lightly on relays during testing. Ensure LPG fuel level is correct before continuing with diagnostics. F-Series models use a compuvalve and Contour models use an Alternate Fuel Control Module (AFCM).

  1. 1) Check Communication With PCM

    Turn ignition switch to OFF position. Connect scan tool. Perform PARAMETER IDENTIFICATION (PID)/DATA MONITOR PROCEDURE . Access the PCM. Access an active PID. If communication is not possible with PCM, see TEST QA under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article. If communication is possible with PCM, go to next step.

  2. 2) Check Communication With Compuvalve (F-Series), Or AFCM (Contour)

    Perform PARAMETER IDENTIFICATION (PID)/DATA MONITOR PROCEDURE . Access the AFCM. Access an active PID. If communication is not possible with AFCM, go to next step. If communication is possible with AFCM, clear DTCs and retest. See CLEARING CODES . If DTC is set again, replace module storing the DTC.

  3. 3) Check Power To Compuvalve (F-Series), Or AFCM (Contour)

    Turn ignition switch to OFF position. Disconnect compuvalve harness connector C4025 (on F-Series) or AFCM harness connector C4001 (on Contour). See Figure or Figure . Turn ignition switch to ON position. Perform the following voltage tests:

    • On Contour (2.0L)

      Measure voltage between chassis ground and AFCM harness connector terminals No. 11 and 16 (White wires).

    • On F150 (5.4L)

      Measure voltage between chassis ground and compuvalve harness connector terminals No. 11 and 13 (White wires).

    • On F350 (6.8L)

      Measure voltage between chassis ground and compuvalve harness connector terminals No. 9, 11 and 13 (White wires).

    If voltage measurements are more than 10 volts, go to next step. If any voltage measurement is 10 volts or less, repair open in affected circuit. See WIRING DIAGRAMS article.

  4. 4) Check Ground To Compuvalve (F-Series), Or AFCM (Contour)

    Turn ignition switch to OFF position. Ensure compuvalve harness connector C4025 (on F-Series) or AFCM harness connector C4001 (on Contour) are disconnected. See Figure or Figure . On Contour, measure resistance between chassis ground and AFCM harness connector C4001 terminals No. 1 (Gray wire) and 2 (Black/White wire). On F-Series, measure resistance between chassis ground and compuvalve harness connector C4025 terminals No. 57, 59, 61, 62, 63 and 64 (Black wires). 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 affected circuit. See WIRING DIAGRAMS article.

  5. 5) Check SCP Link To DLC For Open Or Short To Ground

    Ensure ignition switch is turned to OFF position. Ensure compuvalve harness connector C4025 (on F-Series) or AFCM harness connector C4001 (on Contour) are disconnected. Perform the following resistance tests:

    1. Contour (2.0L) Short To Ground Check

      Measure resistance between chassis ground and AFCM harness connector C4001 terminals No. 5 (Pink/Light Blue wire) and 6 (Tan/Orange wire). See Figure. If resistance is more than 10 k/ohms, go to  CONTOUR (2.0L) OPEN CIRCUIT CHECK. If resistance is 10 k/ohms or less, repair short to ground in affected circuit. See WIRING DIAGRAMS article.

    2. Contour (2.0L) Open Circuit Check

      Measure resistance between AFCM harness connector C4001 terminal No. 5 (Pink/Light Blue wire) and DLC terminal No. 10 (Blue wire). Also, measure resistance between AFCM harness connector C4001 terminal No. 6 (Tan/Orange wire) and DLC terminal No. 2 (Gray wire). See Figure and Figure . If both resistance measurements are less than 5 ohms, replace AFCM. If either resistance measurement is 5 ohms or more, repair open in affected circuit. See WIRING DIAGRAMS article.

    3. F-Series (5.4L & 6.8L) Short To Ground Check

      Measure resistance between chassis ground and compuvalve harness connector C4025 terminals No. 14 (White wire) and 16 (White wire). See Figure. If resistance is more than 10 k/ohms, go to  F-SERIES (5.4L & 6.8L) OPEN CIRCUIT CHECK. If resistance is 10 k/ohms or less, repair short to ground in affected circuit. See WIRING DIAGRAMS article.

    4. F-Series (5.4L & 6.8L) Open Circuit Check

      Measure resistance between compuvalve harness connector C4025 terminal No. 16 (White wire) and DLC terminal No. 10 (Pink/Light Blue wire). Also, measure resistance between compuvalve harness connector C4025 terminal No. 14 (White wire) and DLC terminal No. 2 (Tan/Orange wire). See Figure and Figure . If both resistance measurements are less than 5 ohms, replace compuvalve. If either resistance measurement is 5 ohms or more, repair open in affected circuit. See WIRING DIAGRAMS article.
scientia non olet · About LEMON Manuals