M/T

DTC P0506 - IDLE CONTROL SYSTEM RPM LOWER THAN EXPECTED

DTC DETECTING CONDITION:
- Two consecutive driving cycles with fault

TROUBLE SYMPTOM:
- Engine is difficult to start.
- Engine does not start.
- Erroneous idling
- Engine stalls.

CAUTION: After repair or replacement of faulty parts, conduct CLEAR MEMORY MODE and INSPECTION MODE. Refer to How To Clear Diagnostic Trouble Codes.

Wiring Diagram:

WIRING DIAGRAM

10AV1: CHECK ANY OTHER DTC ON DISPLAY

CHECK: Does the Subaru Select Monitor or OBD-II general scan tool indicate DTC P0505 or P1505?

YES: Inspect DTC P0505 or P1505 using "10. Diagnostics Chart with Trouble Code for MT Vehicles".

NOTE: In this case, it is not necessary to inspect DTC P0506.

NO: Go to step 10AV2.

10AV2: CHECK IDLE AIR CONTROL SOLENOID VALVE.

1. Turn ignition switch to OFF.
2. Remove idle air control solenoid valve from throttle body.
3. Using an air gun, force air into idle air control solenoid valve by-pass air inlet. Confirm that forced air subsequently escapes from both main air passage and assist air passage.

CHECK: Does air flow out?

YES: Go to step 10AV4.

NO: Replace idle air control solenoid valve. After replace, Go to step 10AV3.

10AV3: CHECK IDLE AIR CONTROL SOLENOID VALVE DUTY RATIO.

1. Turn ignition switch to ON.
2. Start engine, and warm-up the engine.
3. Turn all accessory switches to OFF.
4. Read data of idle air control solenoid valve duty ratio using Subaru Select Monitor or OBD-II general scan tool.

NOTE:
- Subaru Select Monitor
For detailed operation procedures, refer to the "READ CURRENT DATA SHOWN ON DISPLAY FOR ENGINE". Refer to Normal Scan Data Values.
- OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II General Scan Tool Instruction Manual.

CHECK: Is the value more than 60 %?

YES: Go to step 10AV4.

NO: END.

10AV4: CHECK BY-PASS AIR LINE.

1. Turn ignition switch to OFF.
2. Remove idle air control solenoid valve from throttle body.
3. Remove throttle body to intake manifold.
4. Using an air gun, force air into solenoid valve installation area and throttle valve interior. Confirm that forced air subsequently escapes from both these areas.

CHECK: Does air flow out?

YES: Replace idle air control solenoid valve.

NO: Replace throttle body.