DTC P0098: Intake Air Temperature Sensor 2 Circuit High Bank 1: Notes

1. - 

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

• Improper idling
• Poor driving performance

Wiring diagram: 

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DTC  .
   1. Turn the ignition switch to ON.
   2. Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine]. Ref. to COMMON (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)

   Is DTC P06B1 displayed? (Current code)

   Yes  : Check for DTC P06B1. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P06B1 SENSOR POWER SUPPLY "A" CIRCUIT LOW

   No  : Go to  2.

2. CHECK DTC  .

   Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine]. Ref. to COMMON (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)

   Is DTC P06B2 displayed? (Current code)

   Yes  : Check for DTC P06B2. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P06B2 SENSOR POWER SUPPLY "A" CIRCUIT HIGH

   No  : Go to  3.

3. CHECK DATA MONITOR  .
   1. Start the engine.
   2. Using the Subaru Select Monitor, read the value in [IAT Sensor #12].
      NOTE:

      For detailed operation procedures, refer to "COMMON (DIAGNOSTICS)". Ref. to  COMMON (DIAGNOSTICS)>DATA MONITOR 

   Is the value of [IAT Sensor #12] less than -40 [°C] (-40°F)?

   Yes  : Go to  4.

   No  : Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

   NOTE:

   In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause. 

4. CHECK FOR POOR CONTACT  .

   Check for poor contact of ECM and manifold absolute pressure and intake air temperature sensor connector.

   Is there poor contact of ECM or manifold absolute pressure and intake air temperature sensor connector?

   Yes  : Repair the poor contact of ECM or manifold absolute pressure and intake air temperature sensor connector.

   No  : Go to  5.

5. CHECK HARNESS BETWEEN ECM AND MANIFOLD ABSOLUTE PRESSURE AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR (OPEN)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from ECM.
   3. Disconnect the connector from the manifold absolute pressure and intake air temperature sensor.
   4. Measure the resistance of harness between ECM connector and the manifold absolute pressure and intake air temperature sensor connector.

      Connector & terminal 

      (E51) No. 33 - (E78) No. 1:

      (E51) No. 34 - (E78) No. 2:

   Is the resistance less than 1 Ω?

   Yes  : Go to  6.

   No  : Repair the following item.

   • Open circuit of harness between ECM connector and the manifold absolute pressure and intake air temperature sensor connector
   • Poor contact of J/C
6. CHECK HARNESS BETWEEN ECM AND MANIFOLD ABSOLUTE PRESSURE AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR (SHORT TO POWER SUPPLY)  .
   1. Connect all connectors.
   2. Turn the ignition switch to ON.
   3. Measure the voltage between ECM connector and engine ground.

      Connector & terminal 

      (E51) No. 34 (+) - Engine ground (-):

   Is the voltage 5 V or more?

   Yes  : Repair the short circuit to power in harness between ECM connector and the manifold absolute pressure and intake air temperature sensor connector.

   No  : Replace the manifold absolute pressure and intake air temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>MANIFOLD ABSOLUTE PRESSURE AND INTAKE AIR TEMPERATURE SENSOR