Note. For circuit identification and wiring diagram, see WIRING DIAGRAMS article. If Powertrain Control Module (PCM) is replaced, PCM must be reprogrammed. See PROGRAMMING . After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-5 under VERIFICATION TESTS to ensure system is functioning properly.
Home/Jeep/Cherokee/Jeep Cherokee III (2001-2004)/Repair manual/Testing & Diagnostics/DTC P0420: 1/1 CATALYTIC CONVERTER EFFICIENCY
Contents
Wiring diagrams Section: Testing & Diagnostics- Engine Controls Self-Diagnostics - Cherokee: Overview
- Engine Controls Self-Diagnostics - Cherokee: Diagnosis
- Engine Controls Self-Diagnostics - Cherokee: Component Locations
- Engine Controls Self-Diagnostics - Cherokee: Other
- DTC P0107: MAP SENSOR VOLTAGE TOO LOW
- DTC P0108: MAP SENSOR VOLTAGE TOO HIGH
- DTC P0112: INTAKE AIR TEMP SENSOR VOLTAGE LOW
- DTC P0113: INTAKE AIR TEMPERATURE SENSOR VOLTAGE HIGH
- DTC P0117: ECT SENSOR VOLTAGE TOO LOW
- DTC P0118: ECT SENSOR VOLTAGE TOO HIGH
- DTC P0121: TPS VOLTAGE DOES NOT AGREE WITH MAP
- DTC P0122: THROTTLE POSITION SENSOR VOLTAGE LOW
- DTC P0123: THROTTLE POSITION SENSOR VOLTAGE HIGH
- DTC P0125: CLOSED LOOP TEMP NOT REACHED
- DTC P0130: 1/1 O2 SENSOR HEATER CIRCUIT MALFUNCTION
- DTC P0131: 1/1 O2 SENSOR SHORTED TO GROUND
- DTC P0132: 1/1 O2 SENSOR SHORTED TO VOLTAGE
- DTC P0133: 1/1 O2 SENSOR SLOW RESPONSE
- DTC P0135: 1/1 O2 SENSOR HEATER FAILURE
- DTC P0136: 1/2 O2 SENSOR HEATER CIRCUIT MALFUNCTION
- DTC P0137: 1/2 O2 SENSOR SHORTED TO GROUND
- DTC P0138: 1/2 O2 SENSOR SHORTED TO VOLTAGE
- DTC P0139: 1/2 O2 SENSOR SLOW RESPONSE
- DTC P0141: 1/2 O2 SENSOR HEATER FAILURE
- DTC P0151: 2/1 O2 SENSOR SHORTED TO GROUND (WITH CALIF. EMISSIONS)
- DTC P0152: 2/1 O2 SENSOR SHORTED TO VOLTAGE (WITH CALIF. EMISSIONS)
- DTC P0153: 2/1 O2 SENSOR SLOW RESPONSE (WITH CALIF. EMISSIONS)
- DTC P0155: 2/1 O2 SENSOR HEATER FAILURE (WITH CALIF. EMISSIONS)
- DTC P0157: 2/2 O2 SENSOR SHORTED TO GROUND (WITH CALIF. EMISSIONS)
- DTC P0158: 2/2 O2 SENSOR SHORTED TO VOLTAGE (WITH CALIF. EMISSIONS)
- DTC P0159: 2/2 O2 SENSOR SLOW RESPONSE (WITH CALIF. EMISSIONS)
- DTC P0161: 2/2 O2 SENSOR HEATER FAILURE (WITH CALIF. EMISSIONS)
- DTC P0171: 1/1 FUEL SYSTEM LEAN
- DTC P0172: 1/1 FUEL SYSTEM RICH
- DTC P0174: 2/1 FUEL SYSTEM LEAN (WITH CALIF. EMISSIONS)
- DTC P0175: 2/1 FUEL SYSTEM RICH (WITH CALIF. EMISSIONS)
- DTC P0201: INJECTOR #1 CONTROL CIRCUIT
- DTC P0202: INJECTOR #2 CONTROL CIRCUIT
- DTC P0203: INJECTOR #3 CONTROL CIRCUIT
- DTC P0204: INJECTOR #4 CONTROL CIRCUIT
- DTC P0205: INJECTOR #5 CONTROL CIRCUIT
- DTC P0206: INJECTOR #6 CONTROL CIRCUIT
- DTC P0300: MULTIPLE CYLINDER MISFIRE
- DTC P0320: NO CRANK REFERENCE SIGNAL AT PCM
- DTC P0340: NO CAM SIGNAL AT PCM
- DTC P0351: IGNITION COIL #1 PRIMARY CIRCUIT
- DTC P0352: IGNITION COIL #2 PRIMARY CIRCUIT
- DTC P0353: IGNITION COIL #3 PRIMARY CIRCUIT
- DTC P0420: 1/1 CATALYTIC CONVERTER EFFICIENCY
- DTC P0432: 2/1 CATALYTIC CONVERTER EFFICIENCY (WITH CALIF. EMISSIONS)
- DTC P0441: EVAP PURGE FLOW MONITOR FAILURE
- DTC P0442: EVAP LEAK MONITOR MEDIUM (.040") LEAK DETECTED, DTC P0455: EVAP LEAK MONITOR LARGE LEAK DETECTED OR DTC P0456: EVAP LEAK MONITOR SMALL (.020") LEAK DETECTED
- DTC P0443: EVAP PURGE SOLENOID CIRCUIT
- DTC P0460: FUEL LEVEL UNIT NO CHANGE OVER MILES OR DTC P0461: FUEL LEVEL UNIT NO CHANGE OVER TIME
- DTC P0462: FUEL LEVEL SENDING UNIT VOLTS TOO LOW
- DTC P0463: FUEL LEVEL SENDING UNIT VOLTS TOO HIGH
- DTC P0500: NO VEHICLE SPEED SENSOR SIGNAL
- DTC P0505: IDLE AIR CONTROL MOTOR CIRCUITS
- DTC P0522: OIL PRESSURE SENSOR VOLTS LOW
- DTC P0523: OIL PRESSURE SENSOR VOLTS HIGH
- DTC P0600: PCM FAILURE SPI COMMUNICATIONS
- DTC P0601: INTERNAL CONTROLLER FAILURE
- DTC P0645: A/C CLUTCH RELAY CIRCUIT
- DTC P1195: 1/1 O2 SENSOR SLOW DURING CATALYST MONITOR
- DTC P1196: 2/1 O2 SENSOR SLOW DURING CATALYST MONITOR (4.0L WITH CALIF. EMISSIONS)
- DTC P1197: 1/2 O2 SENSOR SLOW DURING CATALYST MONITOR (WITH CALIF. EMISSIONS)
- DTC P1282: FUEL PUMP RELAY CONTROL CIRCUIT
- DTC P1294: TARGET IDLE NOT REACHED
- DTC P1296: NO 5 VOLTS TO MAP SENSOR
- DTC P1297: NO CHANGE IN MAP FROM START TO RUN
- DTC P1388: AUTO SHUTDOWN RELAY CONTROL CIRCUIT
- DTC P1389: NO ASD RELAY OUTPUT VOLTAGE AT PCM
- DTC P1391: INTERMITTENT LOSS OF CMP OR CKP
- DTC P1398: MISFIRE ADAPTIVE NUMERATOR AT LIMIT
- DTC P1486: EVAP LEAK MONITOR PINCHED HOSE FOUND
- DTC P1491: RADIATOR FAN CONTROL RELAY CIRCUIT
- DTC P1492: AMBIENT/BATT TEMPERATURE SEN VOLTAGE TOO HIGH
- DTC P1493: AMBIENT/BATT TEMPERATURE SEN VOLTAGE TOO LOW
- DTC P1494: LEAK DETECTION PUMP SW OR MECHANICAL FAULT
- DTC P1495: LEAK DETECTION PUMP SOLENOID CIRCUIT
- DTC P1685: INVALID SKIM KEY
- DTC P1686: NO SKIM BUS MESSAGE RECEIVED
- DTC P1696: PCM FAILURE EEPROM WRITE DENIED
- DTC P1698: NO BUS MESSAGE FROM TRANS CONTROL MODULE
- DTC P1899: P/N SWITCH PERFORMANCE (A/T)
- Engine Controls - Basic Diagnostic Procedures: Diagnosis
- Engine Controls - Basic Diagnostic Procedures: Other
- Engine Controls - System & Component Testing: Overview
- Engine Controls - System & Component Testing: Diagnosis
- Engine Controls - System & Component Testing: Other
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