LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2000 >> Contour SE, 2.5 L, Standard >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Self-Diagnostics - EEC-V - CNG, Flex-Fuel & Gasoline >> System Tests >> Test DP: Vehicle Speed Sensor/Transfer Case Speed Sensor >> Diagnostic Aids

Diagnostic Aids

NOTE: After each service or repair procedure has been completed, reconnect all components. Clear DTCs and perform OBD-II Drive Cycle. See DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. After drive cycle is complete, repeat QUICK TEST  procedures to ensure all EEC-V systems are working properly and DTCs are no longer present.

Delayed engagement of transmission may be caused by mechanical malfunction. Harsh shifts and/or erratic speedometer reading may be caused by a failed speedometer or an open or intermittent ground within the instrument panel (electronic instrument cluster).

Perform this test when directed by QUICK TEST. This system test is intended to diagnose.

NOTE: Proceed to DTC testing steps listed in FAULT CODE SETTING CONDITION  table of fault code setting condition.
FAULT CODE SETTING CONDITION

Fault Code KOEO KOER Continuous Memory
P0500      DP1
P0501      DP20
P1500      DP25
P1501    DP15  

  1. 1) DTC P0500, P0501 Or P1502

    These DTCs indicate PCM detected incorrect output from VSS sometime during vehicle operation. Possible causes for these faults are:
    • Faulty VSS
    • Open Or Shorted Circuit
    • Faulty PCM

    Turn ignition switch to OFF position. Disconnect VSS. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Measure resistance between PCM connector terminal No. 58 and VSS(+) terminal at VSS harness connector. Measure resistance between PCM connector terminal No. 33 and VSS(-) terminal at VSS harness connector. See Fig 1. If both resistance readings are less than 5 ohms, go to next step. If any resistance reading is 5 ohms or more, repair open in VSS circuit.

    Fig 1: Identifying VSS Circuits & Connector Terminals (Except Contour, Cougar & Mystique)
    G99H02106Courtesy of FORD MOTOR CO.

  2. 2) Check VSS Circuits For Shorts To Power Or Ground

    Measure resistance at PCM connector as follows:
    • Measure resistance between PCM connector terminals No. 58 and 33.
    • Measure resistance between PCM connector terminals No. 58 and 103 (PWR GND).
    • Measure resistance between PCM connector terminals No. 58 and 71 (VPWR).

    If all resistance readings are more than 5 ohms, go to next step. If any resistance reading is 5 ohms or less, go to step  12).

  3. 3) Check VSS Resistance

    Measure resistance between VSS terminals. If resistance is not 170-270 ohms, replace VSS. If resistance is 170-270 ohms, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 3) to step 5). No test procedures have been omitted.

  4. 5) DTC P0500, P0501 Or P1502

    This DTC indicates PCM detected incorrect output from VSS sometime during vehicle operation. Possible causes for this fault are:
    • Faulty VSS
    • Open Or Shorted Circuit
    • Faulty PCM

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Raise and support front of vehicle (to allow rotation of front drive wheel). Opposite front wheel must be stationary. Measure voltage between PCM connector terminals No. 58 and 103 while slowly rotating drive wheel. Voltage should fluctuate from less than one volt to more than 5 volts as wheels are rotated. If voltage is as specified, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE . If voltage is not as specified, go to next step.

  5. 6) Check VPWR To VSS

    Turn ignition switch to OFF position. Disconnect VSS connector. Turn ignition switch to ON position. Measure voltage between VPWR and PWR GND terminals at VSS harness connector. See Fig 2-Fig 3 . If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, go to step  10).
    Fig 2: Identifying VSS Circuits & Connector Terminals (Contour, Cougar & Mystique - 2.0L)
    G00013257Courtesy of FORD MOTOR CO.
    Fig 3: Identifying VSS Circuits & Connector Terminals (Contour, Cougar & Mystique - 2.5L)
    G99I02102Courtesy of FORD MOTOR CO.

  6. 7) Check VSS Circuits For Short To Power

    Turn ignition switch to ON position. Measure voltage between PCM connector terminals No. 58 and 103. If voltage is one volt or more, go to step  12). If voltage is less than one volt, go to next step.

  7. 8) Check VSS Circuits For Short To Ground

    Turn ignition switch to OFF position. Measure resistance between PCM connector terminals No. 58 and 103. If resistance is more than 3000 ohms, go to next step. If resistance is 3000 ohms or less, go to step  12).

  8. 9) Check VSS Circuit Resistance

    Measure resistance between PCM connector terminal No. 58 and VSS terminal at VSS harness connector. See Fig 1. If resistance is less than 5 ohms, replace VSS. If resistance is 5 ohms or more, repair open VSS circuit.

  9. 10) Check VSS Ground Circuit Resistance

    Turn ignition switch to OFF position. Ensure PCM and VSS are disconnected. Measure resistance between chassis ground and PWR GND terminal at VSS harness connector. If resistance is less than 5 ohms, repair open in VPWR circuit to VSS. If resistance is 5 ohms or more, repair open in ground 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.

  10. 12) Verify If Short Is In Wiring Harness Or Another Module

    Determine if any other modules are connected to VSS circuit. See appropriate wiring diagram in WIRING DIAGRAMS article. If no other modules are connected to vehicle speed circuit, repair short circuit. If other modules are connected to vehicle speed circuit, disconnect module(s) (one at a time) that are associated with VSS circuit. After disconnecting each module, check again for short circuit. Refer to test step that sent you to this step. Repeat until each associated module has been disconnected or short circuit has been eliminated. If short circuit no longer exists with associated module(s) disconnected, diagnose appropriate module and/or related system. See appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT. If short circuit still exists with all associated modules disconnected, repair short in VSS circuit.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 12) to step 15). No test procedures have been omitted.

  11. 15) KOER DTC P1501: Check PCM VSS PID For Input Signal

    This DTC indicates VSS input signal is out of range. A DTC P1501 will be set and self-test will abort whenever PCM detects VSS input signal during KOER ON-DEMAND SELF-TEST. A noisy VSS input signal from RFI/EMI external source (ignition wires, charging circuits, etc.) are possible causes for this fault.

    Start engine and allow to idle. Using scan tool, select VSS PID from PID/DATA MONITOR & RECORD menu and observe vehicle speed input to PCM. While observing VSS PID, increase engine speed to 2000 RPM and return to idle several times. If VSS PID reading is 3 MPH or more, go to step  22). If VSS PID value is less than 3 MPH, fault cannot be duplicated at this time. Clear DTCs and repeat QUICK TEST . If DTC P1501 is still present, go to TEST Z .

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 15) to step 20). No test procedures have been omitted.

  12. 20) Continuous Memory DTC P0503: Check For Intermittent Fault

    This DTC indicates poor VSS performance. Possible causes for this fault are:
    • Noisy VSS Input Signal From RFI/EMI External Source (Ignition Wires, Charging Circuits Etc.)
    • Damaged Circuit
    • Faulty VSS
    • Faulty VSS Gear(s)

    Turn ignition switch to OFF position. Disconnect VSS sensor. Visually inspect VSS and VSS circuits for potential faults as follows:

    • Loose VSS Circuit Connectors
    • Loose VSS Circuit Connector Terminals
    • Damaged VSS Wiring Harness Insulation
    • Incorrect VSS Circuit Routing
    • Incorrect VSS Installation

    If no faults are found, go to next step. If faults are found, repair as necessary.

  13. 21) Check PCM VSS PID For Input Signal

    Using scan tool, select VSS PID. Test drive vehicle at several steady speeds at more and less than 30 MPH.
    NOTE: On scan tools with Data Record feature, record data for playback to help identify variations.

    During each steady speed, check for VSS PID variations of plus or minus 5 MPH for 10 seconds or more. If any variations occur, go to next step. If variations do not occur, fault cannot be duplicated at this time. Testing is complete.

  14. 22) Check VSS Wiring Harness Routing

    Visually inspect VSS wiring harness. Ensure wiring is not routed near ignition wires or alternator wires. Verify VSS wiring harness is shielded and grounded (if applicable). Repeat step  1) to check VSS circuits. If faults are found, repair as necessary. If no faults are found, fault cannot be duplicated at this time. Go to TEST Z  and check for intermittents.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 22) to step 25). No test procedures have been omitted.

  15. 25) DTC P1500

    This DTC indicates PCM detected intermittent input from VSS. Possible causes for this fault are:
    • Intermittent Open Or Shorted Circuit
    • Faulty VSS
    • Faulty PCM

    Turn ignition switch to OFF position. Disconnect VSS sensor. Visually inspect VSS and VSS circuits for potential faults as follows:

    • Loose VSS Circuit Connectors
    • Loose VSS Circuit Connector Terminals
    • Damaged VSS Wiring Harness Insulation
    • Incorrect VSS Circuit Routing
    • Incorrect VSS Installation

    If no faults are found, go to TEST Z . If faults are found, repair as necessary.

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 25) to step 30). No test procedures have been omitted.

  16. 30) DTC P0500 Or P0503: Visual Inspection

    Transfer Case Speed Sensor (TCSS) provides rotational speed of transfer case output shaft. This signal is used on some models as source of vehicle speed information. Disconnect TCSS 2-pin connector, located on left rear of transmission. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. If connector terminals are okay, go to next step.

  17. 31) Check TCSS Resistance

    Measure resistance between TCSS terminals. If resistance is 1000-1250 ohms, go to next step. If resistance is not 1000-1250 ohms, replace TCSS.

  18. 32) TCSS Output Check

    Road test vehicle and measure frequency between TCSS terminals. With vehicle speed at 30 MPH, frequency should be 265 Hz. Ensure frequency increases and decreases with vehicle speed. If frequency is as specified, go to next step. If frequency is not as specified, remove TCSS from transmission. Inspect TCSS target wheel and repair as necessary. If TCSS target wheel is okay, replace TCSS.

  19. 33) Check For Short To Power

    Turn ignition switch to ON position. Ensure TCSS is disconnected. Measure voltage between TCSS signal terminal at TCSS harness connector and ground. See Fig 4-Fig 5 . If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short to power.
    Fig 4: Identifying TCSS Circuits & Connector Terminals (Pickup 4.2L 4WD With Manual Shift-On-The-Fly)
    G99C02104Courtesy of FORD MOTOR CO.
    Fig 5: Identifying TCSS Circuits & Connector Terminals (Pickup 4.6/5.4L 4WD With Manual Shift-On-The-Fly)
    G00013256Courtesy of FORD MOTOR CO.

  20. 34) Check For Open Circuit

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Measure resistance between TCSS signal terminal at TCSS harness connector and PCM connector terminal No. 7 (Pickup 4.2L) or No. 59 (all other models). See Fig 4-Fig 5 . Measure resistance between SIG RTN terminal at TCSS harness connector and PCM terminal No. 91. If both resistance readings are less than 5 ohms, go to next step. If any resistance reading is 5 ohms or more, repair open circuit.

  21. 35) Check Wiring Harness For Short To Ground

    Measure resistance between SIG RTN and TCSS signal terminals at TCSS harness connector. Measure resistance between TCSS signal terminal at TCSS harness connector and ground. If both resistance readings are more than 10 k/ohms, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION BLOCK PROCEDURE . If any resistance reading is 10 k/ohms or less, repair short to ground in TCSS signal circuit.
scientia non olet · About LEMON Manuals