Infiniti G20 (P11). Manual — part 257

Wiring Diagram

NCEC0284

TEC715

GI

MA

EM

LC

FE

CL

MT

AT

AX

SU

BR

ST

RS

BT

HA

SC

EL

IDX

DTC P0505 IDLE AIR CONTROL VALVE (IACV) — AUXILIARY AIR CONTROL

(AAC) VALVE

Wiring Diagram

EC-439

Diagnostic Procedure

NCEC0285

1

CHECK PCV HOSE CONNECTION

Confirm PCV hose is connected correctly.

OK or NG

OK

©

GO TO 2.

NG

©

Repair or replace.

2

CHECK INTAKE AIR LEAK

1. Start engine and let it idle.
2. Listen for an intake air leak behind the mass air flow sensor.

OK or NG

OK

©

GO TO 3.

NG

©

Discover air leak location and repair.

3

CHECK IACV-AAC VALVE POWER SUPPLY CIRCUIT

1. Stop engine.
2. Disconnect IACV-AAC valve harness connector.

SEF852X

3. Turn ignition switch “ON”.
4. Check voltage between IACV-AAC valve terminals 2, 5 and ground with CONSULT-II or tester.

SEF343X

OK or NG

OK

©

GO TO 5.

NG

©

GO TO 4.

4

DETECT MALFUNCTIONING PART

Check the following.

I

Harness connectors M49, F23

I

Harness for open or short between IACV-AAC valve and ECM relay

©

Repair harness or connectors.

DTC P0505 IDLE AIR CONTROL VALVE (IACV) — AUXILIARY AIR CONTROL

(AAC) VALVE

Diagnostic Procedure

EC-440

5

CHECK IACV-AAC VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminals and IACV-AAC valve terminals as follows.

Refer to Wiring Diagram.

MTBL0390

Continuity should exist.

4. Also check harness for short to ground and short to power.

OK or NG

OK

©

GO TO 6.

NG

©

Repair open circuit or short to ground or short to power in harness or connectors.

6

CHECK AIR CONTROL VALVE (POWER STEERING) OPERATION-I

1. Reconnect ECM harness connector and IACV-AAC valve harness connector.
2. Disconnect vacuum hose connected to air control valve (Power steering) at intake air duct.
3. Start engine and let it idle.
4. Check vacuum hose for vacuum existence.

SEF969X

Vacuum slightly exists or does not exist.

OK or NG

OK

©

GO TO 7.

NG

©

Replace air control valve (Power steering).

GI

MA

EM

LC

FE

CL

MT

AT

AX

SU

BR

ST

RS

BT

HA

SC

EL

IDX

DTC P0505 IDLE AIR CONTROL VALVE (IACV) — AUXILIARY AIR CONTROL

(AAC) VALVE

Diagnostic Procedure (Cont’d)

EC-441

7

CHECK AIR CONTROL VALVE (POWER STEERING) OPERATION-II

Check vacuum hose for vacuum existence when steering wheel is turned.

SEF969X

Vacuum should exist.

OK or NG

OK

©

GO TO 10.

NG

©

GO TO 8.

8

CHECK VACUUM PORT

1. Stop engine.
2. Disconnect vacuum hose connected to air control valve (Power steering) at the vacuum port.
3. Blow air into vacuum port.
4. Check that air flows freely.

SEF970X

OK or NG

OK

©

GO TO 9.

NG

©

Repair or clean vacuum port.

DTC P0505 IDLE AIR CONTROL VALVE (IACV) — AUXILIARY AIR CONTROL

(AAC) VALVE

Diagnostic Procedure (Cont’d)

EC-442