|
|
P0172-FUEL SYSTEM 1/1 RICH (CONTINUED) For the Engine circuit diagram (Refer to 9 - ENGINE - SCHEMATICS AND DIAGRAMS). For a complete wiring diagram Refer to Section 8W. Theory of Operation The fuel feedback system will maintain a stoiciometric fuel/air mixture, 14.7:1, by modifying the injector pulsewidth • When Monitored: • Set Condition: Possible Causes O2 SENSOR HEATER OPERATION EVAP PURGE SOLENOID OPERATION O2 SIGNAL CIRCUIT O2 RETURN CIRCUIT O2 SENSOR MAP SENSOR ECT SENSOR ENGINE MECHANICAL FUEL FILTER/PRESSURE REGULATOR (HIGH) PCM Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - Diagnostic Test 1. ACTIVE DTC NOTE: Check for contaminates that may have damaged an O2 Sensor: contaminated fuel, unapproved sil- With a scan tool, read DTCs. Is the DTC active at this time? Yes >> Go To 2 No >> Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) HB ENGINE ELECTRICAL DIAGNOSTICS 9 - 235 |