LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mitsubishi >> 2002 >> Montero XLS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0551: Power Steering Pressure Sensor Circuit Range/Performance Problem >> Test Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test Procedure

  1. Start engine and let idle. Using scan tool, check data list item No. 27 (power steering pressure switch). Observe scan tool display when steering wheel is stopped and when steering wheel is being turned. With engine at idle, scan tool should display OFF when steering wheel is stopped and ON when steering wheel is being turned. If scan tool displays as specified, problem is intermittent. See INTERMITTENT DIAGNOSTIC TROUBLE CODES . If scan tool does not display as specified, go to next step.
  2. Measure voltage between ground and power steering switch 1-pin connector terminal (Yellow wire) by backprobing. With engine idling and steering wheel stationary, battery voltage should exist. With engine idling and steering wheel being turned, voltage should be one volt or less. If voltage is as specified, go to next step. If voltage is not as specified, go to step  5.
  3. Turn ignition off. Check power steering pressure switch connector for loose, damaged, or corroded terminal. If problem exists, repair or replace connector. Go to step  14. If problem does not exist, go to next step.
  4. Start engine and let idle. Using scan tool, check data list item No. 27 (power steering pressure switch). Observe scan tool display when steering wheel is stopped and when steering wheel is being turned. With engine at idle, scan tool should display OFF when steering wheel is stopped and ON when steering wheel is being turned. If scan tool displays as specified, problem is intermittent. See INTERMITTENT DIAGNOSTIC TROUBLE CODES . If scan tool does not display as specified, replace PCM. Go to step  14.
  5. Turn ignition off. Check power steering pressure switch connector for loose, damaged, or corroded terminal. If problem exists, repair or replace connector. Go to step  14. If problem does not exist, go to next step.
  6. Disconnect power steering pressure switch connector. Turn ignition on. Check voltage between ground and power steering pressure switch connector (Yellow wire). If battery voltage exists, go to step  11. If battery voltage does not exist, go to next step.
  7. Measure voltage between ground and PCM connector D-108 terminal No. 52 (Yellow wire) by backprobing. If battery voltage exists, go to next step. If battery voltage does not exist, go to step  9.
  8. Turn ignition off. Check PCM connector D-108 for loose, damaged, or corroded terminals. If problem exists, repair or replace connector. Go to step  14. If problem does not exist, repair open in Yellow wire between PCM and power steering pressure switch. Go to step  14.
  9. Turn ignition off. Check PCM connector D-108 for loose, damaged, or corroded terminals. If problem exists, repair or replace connector. Go to step  14. If problem does not exist, go to next step.
  10. Check continuity between PCM connector D-108 terminal No. 52 and power steering pressure switch connector. If continuity does not exist, repair Yellow wire. Go to step  14. If continuity exists, replace PCM. Go to step  14.
  11. Replace power steering pressure switch. Test drive vehicle following DTC P0551 set criteria. See DTC SET CRITERIA . Check for DTCs. If DTC P0551 is output, go to next step. If DTC P0551 is not output, go to step  14.
  12. Turn ignition off. Check PCM connector D-108 for loose, damaged, or corroded terminals. If problem exists, repair or replace connector. Go to step  14. If problem does not exist, go to next step.
  13. Check continuity between PCM connector D-108 terminal No. 52 and power steering pressure switch connector. If continuity does not exist, repair Yellow wire. Go to next step. If continuity exists, replace PCM. Go to next step.
  14. Start engine and let idle. Using scan tool, check data list item No. 27 (power steering pressure switch). Observe scan tool display when steering wheel is stopped and when steering wheel is being turned. With engine at idle, scan tool should display OFF when steering wheel is stopped and ON when steering wheel is being turned. If scan tool displays as specified, inspection is complete. If scan tool does not display as specified, go to step  1 and retry diagnostic procedure.
scientia non olet · About LEMON Manuals