Diagnostic Aids
Ensure speedometer is functioning properly before performing this test. If speedometer does not function properly repair speedometer as necessary. See ANALOG INSTRUMENT PANELS - VILLAGER article in ACCESSORIES & EQUIPMENT in appropriate lemon-25® manual. Perform this test when directed by QUICK TEST. This test is intended to diagnose the following:
- Vehicle Speed Sensor (VSS).
- Harness circuit: VSS.
- Powertrain Control Module (PCM).
| Circuit | PCM Pin No. | Wire Color |
|---|---|---|
| VSS | 26 | Green/Yellow |
- 1) DTC P0500
This code indicates PCM detected incorrect output from VSS sometime during vehicle operation. Possible causes for this code are as follows:- Faulty VSS.
- Faulty speedometer.
- Open or short in harness.
- Faulty PCM.
Turn ignition off. Raise and support vehicle with drive wheels off the ground. Connect NGS scan tool to fuse panel DLC. Start engine. Access VSS PID. Place transmission in a forward gear. Observe VSS PID. VSS PID should match speedometer reading (within 10 percent). If VSS PID and speedometer appear to be correct, go to step 10) . If speedometer appears to be correct but VSS PID is inaccurate, go to next step. If speedometer does not operate, repair speedometer before continuing diagnosis. See ANALOG INSTRUMENT PANELS - VILLAGER article in ACCESSORIES & EQUIPMENT in appropriate lemon-25® manual.
- 2) Check VSS Circuits For Open
Turn ignition off. Disconnect PCM. Disconnect instrument cluster connector. Measure resistance of Green/Yellow wire circuit between PCM connector terminal No. 27 and instrument cluster connector. See Fig 1. Also see CIRCUIT PIN IDENTIFICATION table. If resistance is less than 100 ohms, go to next step. If resistance is 100 ohms or more, repair open circuit in Green/Yellow VSS wiring harness. Restore all electrical connections, perform step 10), and repeat QUICK TEST . - 3) Check VSS Circuits For Short To Ground
Turn ignition off. Leave PCM and instrument cluster connector disconnected. Measure resistance between VSS circuit (Green/Yellow wire) and PCM GND terminal No. 96 (Black wire), SIG RTN terminal No. 58 (Black/Yellow wire), and VPWR terminal No. 97 (Black/White wire). If all resistance measurements are greater than 10 k/ohms, go to next step. If any resistance measurement is less than 10 k/ohms, repair short circuit VSS wiring harness. Clear all DTCs and perform step 10) to verify repair. - 4) Check VSS Circuit Continuity
Turn ignition off. Disconnect instrument cluster connector. Measure resistance of Pink/Blue wire between VSS harness connector and instrument cluster connector. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open Pink/Blue wire. Restore all electrical connections and repeat QUICK TEST . - 5) Check VSS Circuit For Short-To-Ground
Turn ignition off. Disconnect VSS. Disconnect instrument cluster harness connector. Measure resistance between Pink/Blue wire at instrument cluster harness connector and ground. If resistance is greater than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair short to ground in VSS circuit. - 6) Check VSS Output Signal
Turn ignition off. Disconnect VSS. Remove VSS from transaxle. Connect a voltmeter set on AC scale to VSS terminals. Measure AC voltage while quickly turning VSS pinion gear. If approximately .5 volt is measured, replace PCM. Restore all electrical connections and repeat QUICK TEST . If voltage is less than .5 volt, replace VSS. Restore all electrical connections and repeat QUICK TEST.NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 6) to step 10). No test procedures have been omitted. - 10) VSS Drive Cycle Test
Start and warm engine to operating temperature. Perform entire drive cycle test 3 times. Place gear selector in Drive. Accelerate quickly to 35 MPH. Coast to idle and stop vehicle. Shut off engine. Perform QUICK TEST . If any DTCs are present, repair as necessary. If no DTCs are present, VSS circuit is okay.