Diagnostic Trouble Codes Troubleshooting

DTC TROUBLESHOOTING

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 check Connect scan tool to DLC with ignition switch turned OFF. Start engine and check MAF value displayed on scan tool. (Refer to "SCAN TOOL DATA :" for normal value.) Is normal value indicated?	Intermittent trouble. Check for intermittent referring to INTERMITTENT AND POOR CONNECTION INSPECTION .	Go to Step 3.
3	Check MAF and IAT sensor power supply voltage Disconnect connector from MAF and IAT sensor with ignition switch turned OFF. Turn ON ignition switch, measure voltage between engine ground and "BLK/RED" wire terminal of MAF and IAT sensor connector. Is voltage 10 - 14 V?	Go to Step 4.	Open wire in "BLK/RED" circuit.
4	Check MAF and IAT sensor ground circuit Measure resistance between "ORN" wire terminal of MAF and IAT sensor connector and engine ground. Is resistance below 5 Ω?	Go to Step 6.	Go to Step 5.
5	Check ground circuit Disconnect connectors from ECM with ignition switch turned OFF. Remove ECM from vehicle body and connect connectors to ECM. Measure resistance between "G04-15" terminal of ECM connector and vehicle body ground. Is resistance below 5 Ω?	Open or high resistance wire in "ORN" circuit.	Open or high resistance wire in "C45-6" and/or "C46-6" circuit. If wires are OK, substitute a known-good ECM and recheck.
6	Check MAF and IAT sensor signal circuit Turn ON ignition switch. Measure voltage between "GRN" wire terminal of MAF and IAT sensor connector and engine ground. Is voltage 0 V?	Go to Step 7.	"GRN" wire shorted to other circuits.
7	Check MAF and IAT sensor signal circuit Disconnect connectors from ECM with ignition switch turned OFF. Measure resistance between "GRN" wire terminal of MAF and IAT sensor connector and vehicle body ground. Is resistance infinity?	Go to Step 8.	"GRN" wire shorted to ground circuit.
8	Check MAF and IAT sensor signal circuit Measure resistance between "GRN" wire terminal of MAF and IAT sensor connector and "C46-29" terminal of ECM connector. Is resistance below 3 Ω?	Go to Step 9.	Open or high resistance wire in "GRN" circuit.
9	Check MAF and IAT sensor output signal Connect connectors to MAF and IAT sensor and ECM with ignition switch turned OFF. Turn ON ignition switch, check voltage between "C46-29" and "G04-15" terminals of ECM connector under the following condition. Voltage between "C46-29" and "G04-15" terminals of ECM connector Ignition ON, leaving engine stop: 0.5 - 1.0 V Idling: 1.3-1.8V Is each value as specified?	Substitute a known-good ECM and recheck.	Faulty MAF and IAT sensor.