Inspection Procedure

HINT:

When the throttle position is slightly opened (the accelerator pedal is slightly depressed) because a floor carpet is overlapped on the accelerator pedal, or if not fully releasing the accelerator pedal, etc., DTC P505 will possibly be detected.
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0505)

Connect the intelligent tester to the DLC3.
Turn the ignition switch ON and turn the tester ON.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

Result

RESULT CHART

Display (DTC Output)	Proceed to
P0505	A
P0511	B

B : Go to step 7

A : Go to next step

CHECK VENTILATION HOSE CONNECTIONS
OK: Ventilation hose is connected correctly and is not damaged.

NG : REPAIR OR REPLACE VENTILATION HOSE

OK : GO TO NEXT STEP
CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leakage.
OK: No leakage from air induction system.

NG : REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK : GO TO NEXT STEP
PERFORM ACTIVE TEST BY INTELLIGENT TESTER (CHECK IAC VALVE OPERATION)
1. Connect the intelligent tester to the DLC3.
2. Turn the ignition switch ON and turn the tester ON.
3. Start the engine and warm it up to the normal operating temperature.
4. Switch off all the accessories (if on).
5. Switch off A/C (if on).
6. Move the gear selector lever to the N position.
7. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / IAC STEP POS.
8. Check that the engine speed varies when the Idle Air Control (IAC) step position is changed using the tester.
OK: Engine speed fluctuates according to IAC step position variation.

OK : CHECK FOR INTERMITTENT PROBLEMS

NG : GO TO NEXT STEP
CHECK A/C SIGNAL CIRCUIT
1. Check the A/C signal circuit (see HOW TO PROCEED WITH TROUBLESHOOTING ).
NG : REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA

OK : GO TO NEXT STEP
CHECK FOR BLOCKAGE IN IAC VALVE AND PASSAGE TO BYPASS THROTTLE VALVE
NG : REPLACE IDLE AIR CONTROL VALVE

OK : GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR (BATTERY - IAC VALVE, IAC VALVE - BODY GROUND)

Measure the voltage between the terminals of the IAC valve wire harness side connector.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
B (I1-2) - GND (I1-3)	9 to 14 V

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 1: Identifying I1 IAC Valve Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR (IAC VALVE - ECM)

Disconnect the I1 IAC valve connector.

Fig 2: Identifying I1 IAC Valve Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the E3 ECM connector.

Measure the resistance of the wire harness side connectors.

Standard resistance (Check for open)

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
RSD (I1-1) - RSD (E3-5)	Below 1 Ω
GND (I1-3) - E01 (E3-7)	Below 1 Ω

Standard resistance (Check for short)

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
RSD (I1-1) or RSD (E3-5) - Body ground	10 kΩ or higher

Fig 3: Disconnecting E3 ECM Connector

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

OK : GO TO NEXT STEP

INSPECT IDLE AIR CONTROL VALVE
1. Inspect the IAC valve (see IDLE AIR CONTROL VALVE ).
NG : REPLACE IDLE AIR CONTROL VALVE

OK : REPLACE ECM