DTC 41: Intake Air Temperature (IAT) Sensor

1. Check Power Supply
   
   Turn ignition off and disconnect IAT sensor harness connector. Turn ignition on. Measure voltage between IAT sensor harness connector terminal "A" (Blue/Yellow wire) and ground. See Fig 1 and Fig 2 . If voltage is approximately 5 volts, go to next step. If voltage is not 5 volts, verify harness continuity of Blue/Yellow wire between IAT sensor and ECM. Repair harness or connectors as necessary.
2. Check Ground Circuit
   
   Turn ignition off. Check IAT sensor harness continuity between terminal "B" (Black wire) and engine ground. See Fig 3 . If continuity is present, go to next step. If continuity is not present, verify harness continuity between IAT sensor and ECM. Repair harness or connectors as necessary.
3. Check Component
   
   Ensure IAT sensor is not damaged or contaminated. Check ECM and IAT sensor harness connectors for damage, corrosion or pushed-out pins. Repair if necessary. If no problems are found, ensure ignition is off.
4. Measure resistance between ECT sensor harness connector terminals as follows:
   • Intake air temperature 68°F (20°C); 2100-2900 ohms.
   • Intake air temperature 122°F (50°C); 680-1000 ohms.

If resistance is not as specified, replace ECT sensor.

Fig 1: Locating IAT Sensor Harness Connector (G20)

Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: DTC 41, Checking Power Supply (G20)

Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 3: DTC 41, Checking Ground Circuit (G20)

Courtesy of NISSAN MOTOR CO., U.S.A.