DTC Troubleshooting

DIAGNOSIS PROCEDURE

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	MAF and IAT sensor and its circuit check Connect scan tool to DLC with ignition switch turned OFF. Turn ignition switch to ON position. Check intake air temp. displayed on scan tool. Is 184°C (363°F) indicated?	Go to Step 3.	Intermittent trouble. Check for intermittent referring to INTERMITTENT AND POOR CONNECTION INSPECTION .
3	Check ECM voltage Disconnect connector from MAF and IAT sensor with ignition switch turned OFF. Check for proper connection to MAF and IAT sensor at "LT GRN/BLK" and "ORN" wire terminals. If OK, then turn ON ignition switch, check voltage between "LT GRN/BLK" wire terminal of MAF and IAT sensor connector and vehicle body ground. Is voltage about 4 - 6 V?	Go to Step 6.	Go to Step 4.
4	Check MAF and IAT circuit insulation Disconnect connectors from ECM with ignition switch turned OFF. Measure resistance between "LT GRN/BLK" wire terminal of ECM connector and body ground. Is resistance infinity?	Go to Step 5.	"LT GRN/BLK" wire shorted to ground circuit. If wire are OK, substitute a known-good ECM and recheck.
5	Check MAF and IAT short circuit Turn ignition switch to ON position. Check voltage between "LT GRN/BLK" wire terminal of ECM connector and vehicle body ground. Is voltage about 0 V?	Go to Step 6.	"LT GRN/BLK" wire shorted to other circuits. If wire are OK, substitute a known-good ECM and recheck.
6	Check MAF and IAT sensor Check MAF and IAT sensor according to Mass Air Flow (MAF) and Intake Air Temperature (IAT) Sensor Inspection . Is it good condition?	Substitute a known-good ECM and recheck.	Replace MAF and IAT sensor.