LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Isuzu >> 1996 >> Rodeo LS, 2.6 E >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 2.6L 4-CYL >> Circuit Testing >> DTC P0502 - VSS Circuit Low Input >> Diagnostic Procedures
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) System Check. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
  2. Check speedometer. If speedometer works, go to step 11). If speedometer does not work, go to next step.
  3. Disconnect VSS harness connector and turn ignition on (with engine off). Connect a test light to positive battery post. Probe VSS connector ground terminal. If test light illuminates, go to step 5). If test light does not illuminate, go to next step.
  4. Repair sensor ground and go to step 16).
  5. With sensor disconnected, turn ignition on. Using DVOM, probe VSS connectors ground and voltage supply. If battery voltage is not displayed on DVOM, go to next step. If battery voltage is displayed, go to step 7).
  6. Repair open or short to ground which may have blown meter fuse and go to step 16).
  7. With sensor disconnected, turn ignition on. Using DVOM, probe VSS connectors ground and speedometer wire. If DVOM reads 7.5-8 volts, go to step 9). If reading is not as specified, go to next step.
  8. Repair open or short circuit between speedometer and VSS. Go to step 16).
  9. Raise and support rear of vehicle. Reconnect VSS harness connector. Using DVOM backprobe terminal containing wire form speedometer and chassis ground. Turn ignition on, with engine off and place transmission in neutral. Rotating rear wheels by hand, observe DVOM readings. If readings are not as specified, go to next step. If readings toggle between .6 volts and 10 volts, go to step 11).
  10. Replace VSS and go to step 16).
  11. With vehicle still in neutral, suspended above ground and ignition on, use scan tool to monitor VSS data while turning rear wheels by hand. If scan tool reads vehicle speed, go to step 13). If scan tool does not read vehicle speed, go to next step.
  12. Repair open or short between PCM and speedometer, speedometer ground, faulty meter circuit board or faulty speedometer. Go to step 16).
  13. Turn ignition off. Disconnect PCM and turn ignition back on. Using DVOM backprobe PCM connector. If DVOM reads near 9.4 volts, go to step 15). If voltage is not as specified, go to next step.
  14. Check for poor PCM connector or damaged terminal. Repair as necessary and go to step 16).
  15. Replace PCM. Program replacement PCM using required equipment. After repair is completed, go to next step.
  16. Read and record FAIL RECORDS data for DTC P0441. Clear DTCs. Operate vehicle within conditions noted in FAIL RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0441 FAILED THIS IGN, return to step 2). If scan tool does not display DTC P0441 FAILED THIS IGN, repair is complete.
scientia non olet · About LEMON Manuals