DTC P050B: Cold Start Ignition Timing Performance [01/2019 - 03/2019]: Procedure

WARNING: This page is about a different car, the 2022 Toyota Corolla, 2021 Toyota Corolla, 2020 Toyota Corolla, and 2019 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050B)

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read the DTCs.

Powertrain > Engine and ECT > Trouble Codes

Result

Result	Proceed to
DTC P050B is output	A
DTC P050B and other DTCs are output	B

HINT:

If any DTCs other than P050B are output, troubleshoot those DTCs first.

Result:

GO TO DTC CHART. Refer to DIAGNOSTIC TROUBLE CODE CHART [01/2019 - 03/2019]

Result:

See step 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 sub-assembly.

Connect the Techstream to the DLC3.
Start the engine.
Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Short FT B1S1, Long FT B1S1.

Powertrain > Engine and ECT > Data List

Tester Display
Short FT B1S1
Long FT B1S1

Read the values displayed on the Techstream at engine idle.

Add the Short FT B1S1 and Long FT B1S1 values to obtain the total fuel trim.

Standard

Techstream Display	Specified Condition
Total of Short FT B1S1 and Long FT B1S1	Between -20 and 20%

Result

Proceed to
OK
NG

Result:

See step 5

Result:

See step 3

INSPECT THROTTLE BODY ASSEMBLY (VISUALLY CHECK THROTTLE VALVE)

Check for foreign matter between the throttle valve and housing. If necessary, clean the throttle body assembly. Also, check that the throttle valve moves smoothly.

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

Result

Proceed to
OK
NG

Result:

See step 10

Result:

See step 4

REPLACE THROTTLE BODY ASSEMBLY

Replace the throttle body assembly.

Refer to REMOVAL [01/2019 - 11/2022]

HINT:

Perform "Inspection After Repair" after replacing the throttle body assembly.

Refer to INITIALIZATION [01/2019 - 11/2022]

Result

Proceed to
NEXT

Result:

See step 16

CHECK PCV SYSTEM

Check the PCV hose connections.

Refer to COMPONENTS [01/2019 - 11/2022]

PCV valve and hose are connected correctly and are not damaged.

Result

Proceed to
OK
NG

Result:

See step 15

Result:

See step 6

CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks.

Refer to ON-VEHICLE INSPECTION [01/2019 - 11/2022]

No leaks from intake system.

Result

Proceed to
OK
NG

Result:

See step 14

Result:

See step 7

CHECK AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

Visually check that the air cleaner filter element sub-assembly is not excessively contaminated with dirt or oil.

The air cleaner filter element sub-assembly is not excessively contaminated with dirt or oil.

Result

Proceed to
OK
NG

Result:

See step 13

Result:

See step 8

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT LINEAR)

Operate the VVT system through the Active Test, and check if the VVT system is operating normally.

Perform the Active Test, referring to DTC P0011 procedure (VVT system for intake camshaft).
Refer to PROCEDURE - Step 2
Perform the Active Test, referring to DTC P0014 procedure (VVT system for exhaust camshaft).
Refer to PROCEDURE - Step 2

Result

Proceed to
OK
NG

Result:

See step 12

Result:

See step 9

READ VALUE USING TECHSTREAM (MAF)

Connect the Techstream to the DLC3.
Start the engine.
Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Speed, MAF and Coolant Temp.

Powertrain > Engine and ECT > Data List

Tester Display
Engine Speed
MAF
Coolant Temp

Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.

Read MAF with the engine speed at 3000 rpm.

Standard

Techstream Display	Condition	Specified Condition
MAF	Engine warmed up Shift lever position: N (neutral) A/C: Off Engine Speed: 3000 rpm	Between 5.0 and 10.0 gm/sec

Result

Proceed to
OK
NG

Result:

See step 18

Result:

See step 10

CLEAR DTC

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCs

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

Result

Proceed to
NEXT

Result:

See step 11

CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

NOTE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the Freeze Frame Data).

Turn the ignition switch to ON.
Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

Powertrain > Engine and ECT > Data List

Tester Display
Coolant Temp

Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Powertrain > Engine and ECT > Utility

Tester Display
All Readiness

Input the DTC: P050B.

Check the DTC judgment result.

Result

Result	Proceed to
NORMAL (DTCs are not output)	A
ABNORMAL (DTC P050B is output)	B

Result:

CHECK FOR INTERMITTENT PROBLEMS. Refer to CHECK FOR INTERMITTENT PROBLEMS [01/2019 - 11/2022]

Result:

See step 18

CHECK AND REPAIR VVT SYSTEM

Check and repair the VVT system.

HINT:

Refer to DTC P0011 Procedure (VVT system for intake camshaft).
Refer to DTC P0011: Camshaft Position "A" - Timing Over-Advanced or System Performance (Bank 1); DTC P0012: Camshaft Position "A" - Timing Over-Retarded (Bank 1) [01/2019 - 03/2019]
Refer to DTC P0014 Procedure (VVT system for exhaust camshaft).
Refer to DTC P0014: Camshaft Position "B" - Timing Over-Advanced or System Performance (Bank 1); DTC P0015: Camshaft Position "B" - Timing Over-Retarded (Bank 1) [01/2019 - 03/2019]

Result

Proceed to
NEXT

Result:

See step 16

REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

Replace the air cleaner filter element sub-assembly.

Result

Proceed to
NEXT

Result:

See step 16

REPAIR OR REPLACE INTAKE SYSTEM

Repair or replace the intake system.

HINT:

Perform "Inspection After Repair" after repairing or replacing the intake system.

Refer to INITIALIZATION [01/2019 - 11/2022]

Result

Proceed to
NEXT

Result:

See step 16

REPAIR OR REPLACE PCV HOSE

Repair or replace the PCV valve or hose.

Result

Proceed to
NEXT

Result:

See step 16

CLEAR DTC

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCs

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

Result

Proceed to
NEXT

Result:

See step 17

CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

NOTE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the Freeze Frame Data).

Turn the ignition switch to ON.
Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

Powertrain > Engine and ECT > Data List

Tester Display
Coolant Temp

Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Powertrain > Engine and ECT > Utility

Tester Display
All Readiness

Input the DTC: P050B.

Check the DTC judgment result.

Result

Result	Proceed to
NORMAL (DTCs are not output)	A
ABNORMAL (DTC P050B is output)	B

Result:

END

Result:

See step 18

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION)

Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM.

Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [06/2018 - ]

HINT:

Repair any problems.

Result

Proceed to
NEXT

Result:

See step 19

CLEAR DTC

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCs

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

Result

Proceed to
NEXT

Result:

See step 20

CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

NOTE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the Freeze Frame Data).

Turn the ignition switch to ON.
Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

Powertrain > Engine and ECT > Data List

Tester Display
Coolant Temp

Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Powertrain > Engine and ECT > Utility

Tester Display
All Readiness

Input the DTC: P050B.

Check the DTC judgment result.

Result

Result	Proceed to
NORMAL (DTCs are not output)	A
ABNORMAL (DTC P050B is output)	B

Result:

END

Result:

See step 21

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

Disconnect the mass air flow meter sub-assembly connector.
Disconnect the ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
C26-1 (FG) - C77-137 (VG)	Always	Below 1 Ω
C26-2 (E2G) - C77-104 (E2G)	Always	Below 1 Ω
C26-3 (VCC) - C77-103 (VCVG)	Always	Below 1 Ω
C26-1 (FG) or C77-137 (VG) - Body ground and other terminals	Always	10 kΩ or higher
C26-3 (VCC) or C77-103 (VCVG) - Body ground and other terminals	Always	10 kΩ or higher

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR

Result:

See step 22

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

Replace the mass air flow meter sub-assembly.

Refer to REMOVAL [01/2019 - 11/2022]

HINT:

If the result of the inspection performed in step 9 (READ VALUE USING TECHSTREAM (MAF)) indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.
Refer to INITIALIZATION [01/2019 - 11/2022]

Result

Proceed to
NEXT

Result:

See step 23

CLEAR DTC

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCs

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

Result

Proceed to
NEXT

Result:

See step 24

CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

NOTE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the Freeze Frame Data).

Turn the ignition switch to ON.
Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

Powertrain > Engine and ECT > Data List

Tester Display
Coolant Temp

Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).
Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Powertrain > Engine and ECT > Utility

Tester Display
All Readiness

Input the DTC: P050B.

Check the DTC judgment result.

Result

Result	Proceed to
NORMAL (DTCs are not output)	A
ABNORMAL (DTC P050B is output)	B

Result:

END

Result:

REPLACE ECM. Refer to REMOVAL [01/2019 - 03/2019]