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 a hand-held tester or OBD II scan tool. Freeze frame data record 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.

Hand-held tester:

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

Connect a hand-held tester to the DLC3.
Turn the ignition switch to ON and turn the tester ON.
Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

Read DTCs.

Result:

DTC OUTPUT RESULT

Display (DTC Output)	Proceed To
P0505	A
P0511 and other DTCs	B

B: Go to step 7 .
A: Go to next step.

CHECK PCV HOSE CONNECTIONS
OK: PCV hose is connected correctly and is not damaged.
1. NG: REPAIR OR REPLACE PCV HOSE
2. 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.
1. NG: REPAIR OR REPLACE
2. OK: Go to next step.
PERFORM ACTIVE TEST USING HAND-HELD TESTER (CHECK IAC VALVE OPERATION)
1. Connect the hand-held tester to the DLC3.
2. Turn the ignition switch to 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 (where on).
5. Switch off A/C (where on).
6. Move the gear selector lever to the N position.
7. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / IAC DUTY RATIO.
8. Check that the engine speed varies when the Idle Air Control (IAC) duty ratio is changed using the tester.
OK:

Engine speed fluctuates according to IAC duty ratio variation.
1. OK: CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT PROBLEMS )
2. NG: Go to next step
CHECK A/C SIGNAL CIRCUIT
1. NG: REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA
2. OK: Go to next step.
CHECK FOR BLOCKAGE IN IAC VALVE AND PASSAGE TO BYPASS THROTTLE VALVE
1. NG: REPLACE IDLE AIR CONTROL VALVE
2. OK: Go to next step.

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

Disconnect the I1 IAC valve connector.
Turn the ignition switch to ON.

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

Standard:

BATTERY - IAC VALVE, IAC VALVE - BODY GROUND

Tester Connections	Specified Conditions
VISC (I1-2) - GND (I1-3)	between 9 V and 14 V

Fig 1: Checking Harness And Connector (Battery - IAC VALVE, IAC Valve - Body Ground)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Reconnect the IAC valve connector.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step.

CHECK HARNESS AND CONNECTOR (IAC VALVE - ECM)

Disconnect the I1 IAC valve connector.
Disconnect the E5 ECM connector.

Check the resistance.

Standard (Check for open):

IAC VALVE - ECM (CHECK FOR OPEN)

Tester Connections	Specified Conditions
DUTY (I1-1) - RSD (E5-5)	Below 1 Ω
GND (I1-3) - E01 (E5-7)	Below 1 Ω

Standard (Check for short):

IAC VALVE - ECM (CHECK FOR SHORT)

Tester Connections	Specified Conditions
DUTY (I1-1) or RSD (E3-5) - Body ground	10 kΩ or higher

Reconnect the ECM connector.
Reconnect the IAC valve connector.

Fig 2: Checking Harness And Connector (IAC Valve - ECM) (1 Of 2)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 3: Checking Harness And Connector (IAC Valve - ECM) (2 Of 2)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step.

INSPECT IDLE AIR CONTROL VALVE (See ON-VEHICLE INSPECTION )
1. NG: REPLACE IDLE AIR CONTROL VALVE
2. OK: REPLACE ECM (See REPLACEMENT )

OBD II scan tool (excluding the hand-held tester):

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

Connect an OBD II scan tool to the DLC3.
Turn the ignition switch to ON and turn the scan tool ON.

Read DTCs using the scan tool.