Toyota Yaris: Sfi System / Air Intake Control Valve Circuit Short to Ground or Open (P166014)

Toyota Yaris XP210 (2020-2025) Reapir and Service Manual / Engine & Hybrid System / G16e-gts (engine Control) / Sfi System / Air Intake Control Valve Circuit Short to Ground or Open (P166014)

DESCRIPTION

The air cleaner is equipped with two inlets, one of which is opened or closed by the Air Intake Control Valve (AICV). This system reduces intake noise and increases engine power at low-to-high engine speed range. When the engine is operating in the low-to-mid speed range, this control operates the AICV to close one of the air cleaner inlets. When the engine speed is more than 3600 rpm, the ECM activates VSV and opens the AICV.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Note
P166014	Air Intake Control Valve Circuit Short to Ground or Open	Voltage of terminal air intake control valve of the ECM is low when the VSV is not operating for 3 seconds or more (1 trip detection logic).	Open or short in vacuum switching valve assembly (for AICV) circuit Vacuum switching valve assembly (for AICV) EFI-MAIN NO. 1 relay ECM	-	SAE: P1660

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

Read Freeze Frame Data using the GTS. The ECM records vehicle and driving condition information as Freeze Frame Data the moment a DTC is stored. 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.

PROCEDURE

1.	PERFORM ACTIVE TEST USING GTS (ACTIVATE THE VSV FOR AICS)

*1	Air
*2	Port E
*3	Port F
*4	Air Filter
*a	Vacuum Switching Valve is On
*b	Vacuum Switching Valve is Off

(a) Disconnect the vacuum hose (port F) from the vacuum switching valve assembly (for AICV).

(b) Enter the following menus.

Powertrain > Engine > Active Test

Tester Display
Activate the VSV for AICS

(c) Check the operation of the vacuum switching valve assembly (for AICV) when the vacuum switching valve assembly (for AICV) is operated using the GTS.

Standard:

GTS Connection	Specified Condition
ON	Air from port E flows out through port F
OFF	Air from port E flows out through the air filter

CHECK FOR INTERMITTENT PROBLEMS

2.	INSPECT VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV)

Click here

REPLACE VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV)

3.	CHECK TERMINAL VOLTAGE (POWER SOURCE OF VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV))

(a) Disconnect the vacuum switching valve assembly (for AICV) connector.

(b) Turn the ignition switch to ON.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
D98-2(+B) - Body ground	Ignition switch ON	11 to 14 V

*a	Front view of wire harness connector (to Vacuum Switching Valve Assembly (for AICV))

GO TO STEP 5

4.	CHECK HARNESS AND CONNECTOR (VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV) - ECM)

(a) Disconnect the vacuum switching valve assembly (for AICV) connector.

(b) Disconnect the ECM connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
D98-1(AIRV) - D104-49(AICV)	Always	Below 1 Ω
D98-1(AIRV) or D104-49(AICV) - Body ground	Always	10 kΩ or higher

REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	INSPECT EFI-MAIN NO. 1 RELAY

Click here

REPLACE EFI-MAIN NO. 1 RELAY

6.	CHECK HARNESS AND CONNECTOR (POWER SOURCE OF EFI-MAIN NO.1 RELAY)

(a) Remove the EFI-MAIN NO. 1 relay from the No. 1 engine room relay block assembly.

*1	No. 1 Engine Room Relay Block Assembly
*2	EFI-MAIN NO. 1 Relay

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
3 (EFI-MAIN NO. 3 relay) - Body ground	Always	11 to 14 V
1 (EFI-MAIN NO. 3 relay) - Body ground	Always	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - EFI-MAIN NO. 3 RELAY)

7.	CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 1 RELAY - VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV))

(a) Remove the EFI-MAIN NO. 1 relay, EFI-MAIN NO. 3 relay and EDU relay from the No. 1 engine room relay block assembly.

HINT:

Remove the EFI-MAIN NO. 3 relay and EDU relay connected between the checked terminals as the coil inside the relay influences the measurement value.

(b) Disconnect the vacuum switching valve assembly (for AICV) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
5(EFI-MAIN NO.1 relay) - D98-2 (+B)	Always	Below 1 Ω
5(EFI-MAIN NO.1 relay) or D98-2 (+B) - Body ground and other terminals	Always	10 kΩ or higher

CHECK FOR INTERMITTENT PROBLEMS

REPAIR OR REPLACE HARNESS OR CONNECTOR

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