Toyota Venza: Cold Start Idle Air Control System Performance (P050A)

Toyota Venza Service Manual / 1ar-fe Engine Control / Sfi System / Cold Start Idle Air Control System Performance (P050A)

MONITOR DESCRIPTION

This monitor will run when the engine is started at an engine coolant temperature of -10 to 50°C (14 to 122°F). The DTC is stored after the engine idles for 13 seconds (2 trip detection logic).

The DTC is designed to monitor the idle air control at cold start. When the engine is started at an engine coolant temperature of below 50°C (122°F), the ECM measures the accumulated mass air flow during engine idling. If the accumulated mass air flow does not reach the specified level within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is stored when the malfunction is detected in consecutive driving cycles (2 trip detection logic).

The electronic throttle control system controls the idle speed. The electronic throttle control system operates the throttle actuator to open and close the throttle valve, and adjusts the intake air amount to achieve the target idle speed.

NOTICE:

The idle speed control learned values are cleared by performing a learned value reset. Idle speed control learning needs to be performed before this DTC can be stored.

DTC No.	DTC Detection Condition	Trouble Area
P050A	Insufficient mass air flow after a cold start (2 trip detection logic).	Throttle body Mass air flow meter PCV system Air cleaner filter element Intake system VVT system ECM Wire harness or connector

MONITOR STRATEGY

Related DTCs	P050A: Cold Start Idle Air Speed Control System
Required Sensors/Components (Main)	Throttle body
Required Sensors/Components (Related)	Mass air flow meter Engine coolant temperature sensor
Frequency of Operation	Once per driving cycle
Duration	10 seconds
MIL Operation	2 driving cycles
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever following DTCs not stored	P0010 (Camshaft Timing Oil Control Valve) P0011 (VVT System - Advance) P0012 (VVT System - Retard) P0016 (VVT System - Misalignment) P0013 (Exhaust Camshaft Timing Oil Control Valve) P0014 (Exhaust VVT System - Advance) P0015 (Exhaust VVT System - Retard) P0017 (Exhaust VVT System - Misalignment) P014C, P014D, P015A, P015B, P2195, P2196, P2237, P2238, P2239, P2252, P2253 (Air Fuel Ratio Sensor) P0102, P0103 (Mass Air Flow Meter) P0115, P0117, P0118 (Engine Coolant Temperature Sensor) P0125 (Insufficient Coolant Temperature for Closed Loop Fuel Control) P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135 (Throttle Position Sensor) P0171, P0172 (Fuel System) P0300 - P0304 (Misfire) P0335 (Crankshaft Position Sensor) P0340, P0342, P0343 (Camshaft Position Sensor) P0365, P0367, P0368 (Exhaust Camshaft Position Sensor) P0351 - P0354 (Igniter) P0500 (Vehicle Speed Sensor) P0705 (Shift Lever Position Switch) P219A, P219C, P219D, P219E, P219F (Air Fuel Ratio Imbalance)
Battery voltage	8 V or higher
Time after engine start	3 seconds or more
Starter	OFF
Engine coolant temperature at engine start	-10°C (14°F) or higher
Engine coolant temperature	-10°C (14°F) or higher, and less than 50°C (122°F)
Engine idling time	3 seconds or more
Fuel-cut	OFF
Vehicle speed	Less than 3 km/h (1.875 mph)
Time after shift position changed	1 second or more
Atmospheric pressure	76 kPa(abs) [570 mmHg(abs)] or higher

TYPICAL MALFUNCTION THRESHOLDS

Accumulated mass air flow

Less than 26.875 g (varies with engine coolant temperature and engine coolant temperature at engine start)

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the ignition switch to ON and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) (See page ).

Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the Techstream on [A].
Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.
Check that "Coolant Temp" in the Data List are within the range of -10 to 50°C (14 to 122°F).
Start the engine and warm it up until the coolant temperature is the same as the coolant temperature in the freeze frame data.
Idle the engine for 1 minute or more.
Enter the following menus: Powertrain / Engine / Trouble Codes [B].
Read the Pending DTCs.
HINT:
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P050A.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows INCOMPLETE or N/A, idle the engine for 3 minutes, let the engine cool down, and then perform steps [A] through [B].

If no pending DTC is output, perform a universal trip and check for permanent DTCs (See page ).
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P0102 (See page ).

CAUTION / NOTICE / HINT

NOTICE:

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

HINT:

Read freeze frame data using the Techstream. 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.	CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A)

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following the menus: Powertrain / Engine / Trouble Codes.

(e) Read the DTCs.

Result	Proceed to
DTC P050A is output	A
DTC P050A and other DTCs are output	B

HINT:

If any DTCs other than P050A are output, troubleshoot those DTCs first.

GO TO DTC CHART

2.	READ VALUE USING TECHSTREAM (FUEL TRIM)

HINT:

Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter.

(a) Connect Techstream to the DLC3.

(b) Start the engine.

(d) Enter the following menus: Powertrain / Engine / Data List / Short FT #1 and Long FT #1.

(e) Read the values displayed on the Techstream at engine idle

(f) Add together the Short FT #1 and FT #1 values to obtain the total fuel trim.

OK:

Total of Short FT #1 and FT #1 values is between -20% and 20%.

GO TO STEP 5

3.	INSPECT THROTTLE BODY ASSEMBLY

(a) Check for deposits around the throttle valve and check the throttle valve condition.

OK:

No deposits around the throttle valve and throttle valve moves smoothly.

GO TO STEP 15

4.	REPAIR OR REPLACE THROTTLE BODY ASSEMBLY

(a) Repair or replace the throttle body assembly (See page ).

HINT:

Perform "Inspection After Repair" after repairing or replacing the throttle body (See page ).

GO TO STEP 14

5.	CHECK PCV SYSTEM

(a) Check the PCV hose connections (See page ).

OK:

PCV hose is connected correctly and is not damaged.

GO TO STEP 10

6.	CHECK INTAKE SYSTEM

(a) Check the intake system for vacuum leaks (See page ).

OK:

No leakage from the intake system.

GO TO STEP 11

7.	CHECK AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

(a) Visually check that the air cleaner filter element is not excessively contaminated with dirt or oil.

OK:

Air cleaner filter element is not excessively contaminated with dirt or oil.

GO TO STEP 12

8.	PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT LINEAR)

(a) Operate the VVT system through the Active test, and check if the VVT system is operating normally.

(1) Perform the Active Test, referring to DTC P0011 Inspection Procedure (VVT system for intake camshaft) (See page ).

(2) Perform the Active Test, referring to DTC P0014 Inspection Procedure (VVT system for exhaust camshaft) (See page ).

GO TO STEP 13

9.	READ VALUE USING TECHSTREAM (MAF)

GO TO STEP 15

GO TO STEP 16

10.	REPAIR OR REPLACE PCV HOSE

(a) Repair or replace the PCV hose.

GO TO STEP 14

11.	REPAIR OR REPLACE INTAKE SYSTEM

(a) Repair or replace the intake system.

HINT:

Perform "Inspection After Repair" after repairing or replacing the intake system (See page ).

GO TO STEP 14

12.	REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

(a) Replace the air cleaner filter element sub-assembly.

GO TO STEP 14

13.	CHECK AND REPAIR VVT SYSTEM

(a) Check and repair the VVT system.

HINT:

Refer to DTC P0011 Inspection Procedure for intake camshaft (See page ).

Refer to DTC P0014 Inspection Procedure for exhaust camshaft (See page ).

14.	CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)

NOTICE:

In this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON and turn the Techstream on.

(g) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

(h) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

(i) Start the engine and warm it up.

(j) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

(k) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(l) Input the DTC: P050A.

(m) Check the DTC judgment result.

Result	Proceed to
NORMAL (DTC is not output)	A
ABNORMAL (DTC P050A is output)	B

END

GO TO STEP 16

15.	CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)

NOTICE:

In this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON and turn the Techstream on.

(g) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

(h) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

(i) Start the engine and warm it up.

(j) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

(k) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(l) Input the DTC: P050A.

(m) Check the DTC judgment result.

Result	Proceed to
NORMAL (DTC is not output)	A
ABNORMAL (DTC P050A is output)	B

CHECK FOR INTERMITTENT PROBLEMS

16.	CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)

(a) Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter and ECM (See page ).

HINT:

Repair any problems.

17.	CHECK WHETHER DTC OUTPUT RECURS

NOTICE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON and turn the Techstream on.

(g) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

(h) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

(i) Start the engine and warm it up.

(j) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(k) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(l) Input the DTC: P050A.

(m) Check the DTC judgment result.

Result	Proceed to
ABNORMAL (DTC P050A is output)	A
NORMAL (DTC is not output)	B

END

18.	CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

REPAIR OR REPLACE HARNESS OR CONNECTOR

19.	REPLACE MASS AIR FLOW METER

(a) Replace the mass air flow meter (See page ).

HINT:

If the result of the inspection performed in step 9 indicated no problem, proceed to the next step without replacing the mass air flow meter.
Perform "Inspection After Repair" after replacing the mass air flow meter (See page ).

20.	CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

NOTICE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON and turn the Techstream on.

(g) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

(h) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

(i) Start the engine and warm it up.

(j) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(k) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(l) Input the DTC: P050A.

(m) Check the DTC judgment result.

Result	Proceed to
NORMAL (DTC is not output)	A
ABNORMAL (DTC P050A is output)	B

END

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