ENGINE (DIAGNOSTICS)(H4DOTC) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC P2021 INTAKE MANIFOLD RUNNER POSITION SENSOR / SWITCH CIRCUIT LOW (BANK 2)

DTC DETECTING CONDITION:

Immediately at fault recognition

TROUBLE SYMPTOM:

• Improper idling

• Engine stalls.

• Poor driving performance

CAUTION:

After repairing or replacing the defective part, perform the Clear Memory Mode and Inspection Mode .

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK CURRENT DATA.

1) Start the engine.

2) Read the data of tumble generator valve position sensor signal (LH) using Subaru Select Monitor or general scan tool.

NOTE:

• Subaru Select Monitor

For detailed operation procedures, refer to “READ CURRENT DATA FOR ENGINE”.

• General scan tool

For detailed operation procedures, refer to the general scan tool operation manual.

Is the voltage less than 0.2 V?

Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the fault condition, and reperform the check.

NOTE:

In this case, there may be a temporary connector contact failure.

2.CHECK POWER SUPPLY OF TUMBLE GENERATOR VALVE ASSEMBLY LH.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from tumble generator valve assembly LH.

3) Turn the ignition switch to ON.

4) Measure the voltage between tumble generator valve assembly LH connector and engine ground.

Connector & terminal

(E51) No. 3 (+) — Engine ground (−):

Is the voltage 4.5 V or more?

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit in harness between ECM and tumble generator valve assembly LH connector

• Poor contact in ECM connector

• Poor contact of coupling connector

3.CHECK HARNESS BETWEEN ECM AND TUMBLE GENERATOR VALVE ASSEMBLY LH CONNECTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from the ECM.

3) Measure the resistance of harness between ECM and tumble generator valve assembly LH.

Connector & terminal

(B134) No. 16 — (E51) No. 1:

Is the resistance less than 1 Ω?

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit in harness between ECM and tumble generator valve assembly LH connector

• Poor contact of coupling connector

4.CHECK HARNESS BETWEEN ECM AND TUMBLE GENERATOR VALVE ASSEMBLY LH CONNECTOR.

Measure the resistance between ECM and chassis ground.

Connector & terminal

(B134) No. 16 — Chassis ground:

Is the resistance 1 MΩ or more?

Repair the short circuit to ground in harness between ECM and tumble generator valve assembly LH connector.

5.CHECK FOR POOR CONTACT.

Check for poor contact of tumble generator valve assembly LH connector.

Is there poor contact in ECM or the tumble generator valve assembly LH connector?

Repair the poor contact in ECM or tumble generator valve assembly LH connector.

Replace the tumble generator valve assembly LH.