DTC Troubleshooting

NOTE: Before this trouble shooting is performed, read the precautions for DTC troubleshooting referring to PRECAUTIONS FOR DTC TROUBLESHOOTING .

DTC TROUBLESHOOTING CHART

Step	Action	YES	NO
1	Was "Engine and Emission Control System Check" performed?	Go to Step 2.	Go to ENGINE AND EMISSION CONTROL SYSTEM CHECK .
2	EVAP leak detecting pump check Check EVAP leak detection pump for operation referring to "EVAP Leak Detecting Pump Check" under EVAP LEAK CHECK MODULE INSPECTION . Is it in good condition?	Go to Step 3.	Replace EVAP leak check module.
3	Wire harness check Check control and ground circuits of EVAP leak detection pump for condition referring to Step 2 of DTC P1422: EVAPORATIVE EMISSION SYSTEM LEAK DETECT PUMP STUCK OFF . Are they in good condition?	Go to Step 4.	Control and ground circuits of EVAP leak detecting pump are open, short and/or high resistance.
4	EVAP leak check pressure sensor check Check EVAP leak check pressure sensor for performance referring to "EVAP Leak Check Pressure Sensor Check" under EVAP LEAK CHECK MODULE INSPECTION . Is it in good condition?	Go to Step 5.	Replace EVAP leak check module.
5	EVAP leak check pressure sensor check Perform visual check of EVAP leak check module referring to "EVAP Leak Check Module Visual Check" under EVAP LEAK CHECK MODULE INSPECTION . Is it in good condition?	Substitute a known-good ECM and recheck.	Replace EVAP leak check module.