DTC P0500 - Vehicle Speed Sensor (VSS) Circuit Failure

NOTE: For component terminal identification, see TERMINAL IDENTIFICATION in this article. For wiring diagrams, see WIRING DIAGRAMS article.

If using scan tool, go to step 4). On Stealth and 3000GT, go to step 3). VSS is located in speedometer. VSS component testing procedures using DVOM require removal of instrument panel. Removal and installation of instrument panel is basically an unbolt and bolt-on procedure.
DO NOT disconnect connectors. Using DVOM, check continuity between indicated VSS terminals. See Fig 1 . Ensure continuity pulses on and off with speedometer shaft revolution. If continuity is not as specified, replace VSS. If continuity is as specified, go to step 5).

Fig 1: Identifying VSS Test Terminals (Diamante)
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA
VSS is located at end of speedometer cable at transmission. Connect battery, resistor (3-10 ohms) and voltmeter to indicated terminals. See Fig 2 . Ensure voltage pulses 4 times per speedometer shaft revolution. If voltage is not as specified, replace VSS. If voltage is as specified, go to step 5).

Fig 2: Testing VSS (Stealth & 3000GT)
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA
With an assistant, road test vehicle. Drive vehicle at 25 MPH. Using scan tool, read vehicle speed. If scan tool does not read 25 MPH, replace VSS. If scan tool reads 25 MPH, go to next step.
Turn ignition switch to OFF position. Disconnect PCM connector. Using DVOM, check continuity between chassis ground and PCM connector terminal No. 86. Move vehicle. Ensure continuity pulses on and off with tire revolution. If continuity is not as specified on Stealth and 3000GT, go to step 7). On all other models, go to next step. If continuity is as specified, go to step 10).

With PCM connector disconnected, disconnect VSS connector. Ground PCM connector terminal No. 66 (No. 86 on Diamante). Using DVOM, check for continuity between chassis ground and specified VSS connector terminal. See PCM-TO-VSS CIRCUIT IDENTIFICATION table. See Fig 3 and Fig 4 . If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.

PCM-TO-VSS CIRCUIT IDENTIFICATION

Application	Terminal No.
Diamante	9

Fig 3: Identifying VSS Connector Terminals (Diamante)

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA

Fig 4: Identifying VSS Connector Terminals Stealth & 3000GT

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA

With VSS connector disconnected, check for continuity between chassis ground and specified VSS connector terminal. See Fig 3 and Fig 4 . See VSS GROUND CIRCUIT IDENTIFICATION table. If continuity does not exist, repair wiring harness as necessary. If continuity exists on Stealth and 3000GT, go to next step. On all other models, go to step 9).

VSS GROUND CIRCUIT IDENTIFICATION

Application	Terminal No.
Diamante	13
Stealth & 3000GT	2

Check for voltage between chassis ground and VSS connector terminal No. 1. If battery voltage does not exist, repair wiring harness as necessary. If battery voltage exists, go to next step.

With VSS connector disconnected, turn ignition switch to ON position. Using DVOM, check for voltage between chassis ground and specified VSS connector terminal. See VSS VOLTAGE FEED CIRCUIT IDENTIFICATION table. If voltage is not 4.5-4.9 volts, replace PCM. If voltage is as specified, condition required to set DTC is not present at this time. Go to next step.

VSS VOLTAGE FEED CIRCUIT IDENTIFICATION

Application	Terminal No.
Diamante	9
Stealth & 3000GT	3

Test is complete. Intermittent problem may exist. Road test vehicle (if necessary) and attempt to duplicate conditions that caused original complaint. Recheck for DTCs. If no DTCs are displayed, go to INTERMITTENT DTCS .