P0505

SYSTEM DESCRIPTION
This system automatically controls engine idle speed to a specified level. Idle speed is controlled through fine adjustment of the amount of air which bypasses the throttle valve via IACV-AAC valve. The IACV-AAC valve opens and closes according to the signal sent from the ECM. The camshaft position sensor detects the actual engine speed and sends a signal to the ECM. The ECM then controls the IACV-AAC valve so that engine speed coincides with the target value memorized in ECM. The target engine speed is the lowest speed at which the engine can operate steadily. The optimum value stored in the ECM is determined by taking into consideration various engine conditions, such as during warm up, deceleration, and engine load (air conditioner, Power steering and cooling fan operation).

COMPONENT DESCRIPTION
The IACV-AAC valve is moved by open and close signals from the ECM. When the open signal is sent to the valve, the amount of air that will flow through the valve increases. The more air that flows through the valve, the higher the idle speed. When the close signal is sent to the valve, the amount of air decreases.

CONSULT REFERENCE VALUE IN DATA MONITOR MODE

ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values and are measured between each terminal and engine ground.

ON BOARD DIAGNOSIS LOGIC

DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

NOTE:
- If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.
- Perform "Procedure for malfunction A" first. If DTC cannot be confirmed, perform "Procedure for malfunction B".

Procedure for malfunction A

With Consult
1. Turn ignition switch "ON".
2. Select "DATA MONITOR" mode with CONSULT.
3. Start engine and run it at idle at least 2 seconds.
4. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR

With Generic Scan Tools
1. Start engine and run it at idle at least 2 seconds.
2. Select "MODE 7" with GST.
3. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR

Without Scan Tools
1. Start engine run it and at least idle seconds.
2. Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
3. Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
4. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

Procedure for malfunction B

TESTING CONDITION: Before performing the following procedure, confirm battery voltage is more than 11 V at idle.

With Consult
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch "OFF" and wait at least 5 seconds.
3. Turn ignition switch "ON" again and select "DATA MONITOR" mode with CONSULT.
4. Start engine and run it for at least 1 minute at idle speed.
5. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR

With Generic Scan Tools
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch "OFF" and wait at least 5 seconds.
3. Start engine again and run it for at least 1 minute at idle speed.
4. Select "MODE 7" with GST.
5. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR

Without Scan Tools
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch "OFF" and wait at least 5 seconds.
3. Start engine again and run it for at least 1 minute at idle speed.
4. Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
5. Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
6. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

WIRING DIAGRAM

DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION

With Consult
1. Disconnect IACV-AAC valve harness connector.

2. Check resistance between terminals (2) and (3), (3) and (4).

Note: "Cold" and "Hot" mean the temperature of coils in IACV-AAC valve.

"Cold": -10°C (14°F) - 50°C (122°F)
"Hot": 50°C (122°F) - 100°C (212°F)

3. Reconnect IACV-AAC valve harness connector.
4. Start engine and warm it up sufficiently.
5. Perform "IACV-AAC/V OPENING" in "ACTIVE TEST" mode with CONSULT
6. Check "MAS AIR/FL SE" value during changing the valve opening from 20% to 80%.
"MAS AIR/FL SE" value should be increased more than 0.15 V.
7. If NG, replace IACV-AAC valve.

Note: Do not use "FUNCTION TEST" mode with CONSULT.

OR

Without Consult
1. Disconnect IACV-AAC valve harness connector.