LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 2002 >> XL-7 Plus >> Repair and Diagnosis >> External Pages >> Different car >> Section 19 (Engine Controls - Self-Diagnostics - 3.2L) >> Diagnostic Tests >> DTC P0502: Vehicle Speed Sensor Circuit - Low Input >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Isuzu Rodeo Sport, 2002 Isuzu Rodeo, 2002 Isuzu Axiom, and 2002 Honda Passport. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
  2. Observe speedometer while test driving vehicle. If speedometer works, go to step  10. If speedometer does not work, go to next step.
  3. Turn ignition off. Disconnect Vehicle Speed Sensor (VSS) 3-pin harness connector. VSS is located in transmission tailshaft housing. Turn ignition on. Using test light connected to battery voltage, probe VSS harness connector terminal No. 2 (Black wire). See Fig 1. If test light illuminates, leave harness connector disconnected and go to step  5. If test light does not illuminate, go to next step.
  4. Repair open in Black wire (VSS ground) between ground point E-23 and VSS. See WIRING DIAGRAMS article. Ground point is located at right rear corner of engine compartment, on fender well. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  5. Turn ignition on. Using DVOM, measure voltage between VSS harness connector terminals No. 1 (Red/Green wire) and No. 2 (Black wire). See Fig 1. If battery voltage exists, leave harness connector disconnected and go to step  7. If battery voltage does not exist, go to next step.
  6. Repair open or short to ground in Red/Green wire (ignition voltage) between PCM and VSS. See WIRING DIAGRAMS article. After repair ensure fuse is not blown. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  7. Turn ignition on. Using DVOM, measure voltage between ground and VSS harness connector terminal and No. 3 (Black/Yellow wire). Voltage reading should be 7.5-8.0 volts. If voltage is as specified, go to step  9. If voltage is not as specified, go to next step.
  8. Check for and repair open or short in Black/Yellow wire between speedometer and VSS. See WIRING DIAGRAMS article. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  9. Replace speedometer. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  10. Turn ignition off. Disconnect MAF sensor 3-pin harness connector. MAF sensor is located in air intake pipe, at air cleaner housing. Remove air cleaner assembly. Disconnect White 16-pin in-line harness connector H-3. Harness connector is located on left inner fender panel behind air cleaner housing. Connect fused jumper wire between battery voltage and White 16-pin in-line harness connector H-3 terminal No. 16 (Red/Green wire) on transmission side of in-line harness connector. See Fig 2. See WIRING DIAGRAMS article. Connect jumper wire between positive side of DVOM and in-line harness connector H-6 terminal No. 16 (Black/Yellow wire) on transmission side of in-line harness connector. Connect negative side of DVOM to ground. Raise and support rear of vehicle. Place transmission in Neutral. Turn ignition on. Observe DVOM readings, while rotating rear wheels by hand. Voltage reading should toggle back and forth between .6-10.0 volts. If voltage toggles as specified, go to next step. If voltage does not toggle as specified, go to step  12.
  11. Replace VSS. See REMOVAL, OVERHAUL & INSTALLATION article. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  12. Check for and repair open or short between PCM and speedometer harness connector. See WIRING DIAGRAMS article. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem with wiring is found, go to next step.
  13. Replace and reprogram PCM. See POWERTRAIN CONTROL MODULE REPLACEMENT  under POWERTRAIN CONTROL MODULE. Use scan tool to clear DTC and verify repair.
Fig 1: Identifying Vehicle Speed Sensor Harness Connector Terminals
G00077232Courtesy of ISUZU MOTOR CO.
Fig 2: Identifying In-Line Harness Connectors H-3 & H6 Terminals
G00077233Courtesy of ISUZU MOTOR CO.
scientia non olet · About LEMON Manuals