LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2003 >> Tribute LX, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 26 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0140: Ho2S (Rear) Circuit, No Activity Detected >> Diagnosis & Repair Procedure

Diagnosis & Repair Procedure

WARNING: This page is about a different car, the 2002 Mazda Protege5 and 2002 Mazda Protege. However, it is still accessible from the selected car via links, so may be relevant.
  1. Turn ignition off. Connect scan tool to DLC-2. Turn ignition on, engine off. Monitor for FREEZE FRAME DATA and ensure data has been recorded. Check service bulletins for repair information related to this DTC. If repair information is not available, go to next step. If repair information is available, perform diagnosis and repair as necessary. After repair, go to step  9
  2. Turn ignition switch off and then start engine. Using scan tool, check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If any other DTCs, except P0131, are present, repair those DTCs first. If no other DTCs, except P0131, are present, go to next step.
  3. Check if DTC P0140 is present in FREEZE FRAME DATA. If DTC is present, go to next step. If DTC is not present, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
  4. Start engine and warm up to operating temperature. Using scan tool, access O2S12 PID data. Race engine at least 10 times in neutral. Scan tool should display O2S12 PID is more than .55 volt at least once during engine racing. If PID voltage is as specified, go to step  7. If PID voltage is not as specified, go to next step.
  5. Check rear HO2S installation. If rear HO2S is not loose, go to next step. If rear HO2S is loose, repair as necessary and go to step  9.
  6. Check for leaks in exhaust system upstream of rear HO2S. If problem is found, repair as necessary and go to step  9. If no leaks are found, check for open or short to ground in Yellow/Blue wire between rear HO2S harness connector terminal "A" and PCM 104-pin harness connector terminal No. 35. Repair as necessary. See Figure and Figure . See WIRING DIAGRAMS article. Go to step  9. If no problem is found, replace rear HO2S and go to step  9.
  7. Check cooling system for combustion gases. If no problem is found, go to next step. If combustion gases are found in cooling system, repair leak and go to step  9.
  8. Check engine compression. Engine compression should be a minimum of 119 psi (8.4 kg/cm2 ) at 300 RPM with a maximum variation of 28 psi (2 kg/cm2 ). If compression is as specified, go to next step. If compression is not as specified, repair as necessary and go to next step. If no problem is found, go to next step.
  9. Reconnect all connectors. Turn ignition switch on. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. Using scan tool, access ECT and RPM PIDs. Ensure ECT PID is more than 158°F (70°C). Increase engine speed to more than 1500 RPM (RPM PID reading) for more than 30 seconds. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If DTC P0140 is present, replace PCM and go to next step If DTC P0140 is not present, go to next step.
  10. Cycle ignition switch from off to on. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If no other DTCs are present, testing is complete. If any other DTC is present, go to applicable test and repair.
scientia non olet · About LEMON Manuals