After Engine Stops due to Stop and Start System, Engine does not Restart [10/2023 - ]: Procedure

1. Enter the following menus: Powertrain / Stop and Start / Utility / Vehicle Control History (RoB).

   Powertrain > Stop and Start > Utility 

   Tester Display
   Vehicle Control History (RoB)

2. Check vehicle control history.

   Result

   Result	Proceed to
   Vehicle control history item Hood Open during Stop&Start (Engine Stall) stored	A
   The above Vehicle control history item not stored	B

Result: 

B 

See step  3

Result: 

A 

See step  2

1. Check the condition of the engine hood.

   Check with the driver to confirm whether or not the engine hood was opened during stop and start control.

   Result

   Result	Proceed to
   Engine hood was not opened during stop and start control	A
   Engine hood was opened during stop and start control	B

Result: 

A 

GO TO ENGINE HOOD COURTESY SWITCH CIRCUIT 

Refer to Engine Hood Courtesy Switch Circuit [10/2023 - ]

Result: 

B 

ENGINE STALL DUE TO ENGINE HOOD BEING OPENED DURING STOP AND START CONTROL EXPLAIN THAT ENGINE RESTART BECOMES PROHIBITED 

1. Consult with the customer to determine if they performed operations that could result in an AT engine stall.

   HINT: 

   (ex.) Heavy load, frequent shifts, etc.

   Result

   Result	Proceed to
   Driver operations that could cause engine stall were performed	A
   None of the above conditions are met	B

Result: 

A 

ENGINE STALL DUE TO DRIVER OPERATION 

Result: 

B 

See step  4

1. Following the instructions on the GTS screen, check for SFI system DTCs.

   Result

   Result		Proceed to
   SFI system poor startability DTCs or RoBs not output, but SFI system poor startability related DTCs or RoBs are output. HINT:  "Engine stall" DTCs, misfires, poor fuel pressure, crank angle sensor, etc. If SFI system poor startability DTCs/RoBs are output, first check that there was not a failure to restart from Stop and Start in "8. CHECK VEHICLE CONTROL HISTORY AND PROBLEM SYMPTOMS", and then check "SFI system poor startability DTCs /RoBs".		A
   None of the above conditions are met	After engine stalls, when starting engine using key or push switch operation, starter does not rotate. Even after vehicle brought in, when starting engine using key or push switch operation, starter does not rotate.	B
   	When restarting engine from idling stop, starter did not rotate. Even after vehicle brought in, when restarting engine from idling stop, starter does not rotate.	C
   	When restarting engine from idling stop, starter rotated. Unknown whether starter rotated (does not remember).	D

Result: 

A 

GO TO SFI SYSTEM (ROB CHART) 

Diagnostic trouble code chart :

Refer to DIAGNOSTIC TROUBLE CODE CHART [10/2023 - 11/2024] , or refer to DIAGNOSTIC TROUBLE CODE CHART [11/2024 - ]

Vehicle control history (RoB):

Refer to VEHICLE CONTROL HISTORY (RoB) [12/2021 - 11/2024] , or refer to VEHICLE CONTROL HISTORY (RoB) [11/2024 - ]

Result: 

B 

GO TO THEFT DETERRENT/SMART ENTRY (START FUNCTION) (ENGINE DOES NOT START) 

Refer to Engine does not Start [12/2021 - ]

Result: 

C 

INSPECT STARTER SYSTEM 

1. Inspect battery

   Refer to ON-VEHICLE INSPECTION [10/2023 - ]

2. Inspect starter system

   Refer to Starter Signal Circuit [10/2023 - ]

Result: 

D 

See step  5

1. Perform an operation check of the stop and start system to confirm what kind of operations result in the engine failing to restart after it has been stopped by the stop and start system.

   Refer to OPERATION CHECK [10/2023 - ]

   Result

   Result	Proceed to
   While vehicle is stopped with the engine stopped by idling stop, the engine cannot restart when attempting to drive forward.	A
   During idling stop, an operation that should restart the engine (brake off, shift operation, etc.) is performed, but there is no response to the start request (refer to Data List).	B

Result: 

B 

IDENTIFY START REQUEST LOCATION 

1. Check the Data List items for countermeasures, and inspect the possible causes of engine start requests not being issued.

   HINT: 

   Depending on vehicle, some items may not be displayed.

   ENGINE START REQUEST (BRAKE RELEASE):
   
   

   Countermeasures and Related Areas	Start Conditions
   When the engine is stopped by stop and start control, and the brakes are operated but a start request is not issued, inspect the following components:  Stop light switch (ECM) Stop light switch (ABS/VSC) Brake master pressure sensor (Brake system) Acceleration sensor Stop light switch circuit	Data List / Stop Light SW (ECM) (OFF: Release brake pedal) Data List / Stop Light SW (ABS/VSC) (OFF: Release brake pedal) Data List / Master Cylinder Pressure (Release brake pedal (However, when brake hold is operating, even though the brake pedal is released there is no intention of forward motion, so the engine will not start))

   ENGINE START REQUEST (EXITED VEHICLE), ENGINE START REQUEST (DRIVER SIDE BUCKLE), ENGINE START REQUEST (DRIVER DOOR):
   
   

   Countermeasures and Related Areas

   Start Conditions

   When the engine is stopped by stop and start control, and the driver exits the vehicle but a start request is not issued, inspect the following components:  Driver seat belt buckle switch circuit (DTC U0155-87 (Instrument Panel Cluster (IPC) communication interrupted) Front seat inner belt assembly RH Driver seat courtesy switch circuit (DTC U0140-87 (Main body system communication interrupted)) Driver seat courtesy switch circuit

   Data List / Driver Courtesy Switch Signal (ON: Driver door open) Driver seat belt unfastened

   ENGINE START REQUEST (SHIFT LEVER)
   
   

   Countermeasures and Related Areas	Start Conditions
   When the engine is stopped by stop and start control, and a shift operation is performed but a start request is not issued, inspect the following components:  Shift lever assembly Engine control ECU (or transmission control ECU)	Data List / Shift Position (Other than D or P)

   ENGINE START REQUEST (CANCEL SW)
   
   

   Countermeasures and Related Areas	Start Conditions
   When the engine is stopped by stop and start control, and the stop and start cancel switch is pressed but a start request is not issued, inspect the following components:  Stop and start cancel switch circuit	Data List / Stop&Start Cancel Switch (ON: Stop and start system cancel switch (electric parking brake switch assembly) pressed

   ENGINE START REQUEST (STEERING)
   
   

   Countermeasures and Related Areas	Start Conditions
   When the engine is stopped by stop and start control, and a steering operation is performed but a start request is not issued, inspect the following components:  Steering sensor Steering system Engine stop and start ECU	Data List / Steering Angle (Steering angle 25 deg or more since idling stop)

   ENGINE START REQUEST (CLUTCH PEDAL ON)
   
   

   Countermeasures and Related Areas	Start Conditions
   When the engine is stopped by stop and start control, and a clutch operation is performed but a start request is not issued, inspect the following components:  Clutch upper switch Engine stop and start ECU	OFF: Clutch pedal depressed

   ENGINE START REQUEST (CLUTCH LOWER SW ON)
   
   

   Countermeasures and Related Areas	Start Conditions
   When the engine is stopped by stop and start control, and a clutch operation is performed but a start request is not issued, inspect the following components:  Clutch lower switch Engine stop and start ECU	ON: Clutch pedal is fully depressed all the way

   ENGINE START REQUEST (A/C)
   
   

   Countermeasures and Related Areas

   Start Conditions

   Check the heater and air conditioner system conditions. When the heater and air conditioner system start conditions are fulfilled but a start request is not issued, inspect the following components: Heater and air conditioner system

   Air conditioning amplifier assembly internal counter ended All of the following conditions apply: Blower Switch: ON condition Evaporator temperature is at or above the threshold value (threshold varies according to factors including temperature, humidity and sunlight amount levels) Any of the following conditions apply: Blower Switch, A/C Switch: Changed from OFF to ON after certain period of time since engine stopped by stop and start system Defogger switch (front defroster): Turned from OFF to ON Changed from stop and start priority control to normal control

   ENGINE START REQUEST (ACCELERATOR)
   
   

   Countermeasures and Related Areas	Start Conditions
   When the engine is stopped by stop and start control, and the accelerator pedal is depressed but a start request is not issued, inspect the following components:  Accelerator Pedal Sensor Engine control ECU (or transmission control ECU)	Data List / Idle (OFF: Accelerator pedal is depressed)

   ENGINE START REQUEST (BRAKE NEGATIVE PRESSURE LOW)
   
   

   Countermeasures and Related Areas

   Start Conditions

   When the engine is stopped by stop and start control, and the brake pedal is depressed further or the brakes are pumped repeatedly but a start request is not issued, inspect the following components:  Brake booster vacuum decreased Vacuum sensor assembly or vacuum sensor assembly (atmospheric pressure sensor) Brake booster assembly Brake master pressure sensor (Brake system) Engine stop and start ECU

   Data List / Brake Negative Pressure (Decreased vacuum inside brake booster (less than 37.5 kPa) (varies with brake master fluid pressure))

   ENGINE START REQUEST (IG SWITCH)
   
   

   Countermeasures and Related Areas	Start Conditions
   When the engine is stopped by stop and start control, and push start switch / key operation is performed but a start request is not issued, inspect the following components:  Smart key ECU assembly (Push start switch)/IG Switch (Mechanical key) Push start switch Engine stop and start ECU	Starter is operating When Data List / Starter Type (Tandem Starter): Data List / Starter Motor (ON: During cranking) When Starter Type (Other than Tandem Starter): Data List / Starter (ON: During starter operation)

   ENGINE START REQUEST (SHIFT P POSITION AND BRAKE)
   
   

   Countermeasures and Related Areas

   Start Conditions

   When the engine is stopped by stop and start control with the transmission in the P position, and the brake pedal is depressed but a start request is not issued, inspect the following components:  Shift lever assembly Stop light switch circuit Engine control ECU (or transmission control ECU) Engine stop and start ECU Skid control ECU (brake actuator assembly)

   Data List / Stop And Start Control Mode (Stop condition: Engine stopped by stop and start control) Data List / Shift Position (P) Data List / Stop Light SW (ABS/VSC) (ON: Depress brake pedal -> OFF: Release brake pedal -> ON: Depress brake pedal) Data List / Stop Light SW (EFI) (ON: Depress brake pedal -> OFF: Release brake pedal -> ON: Depress brake pedal) Data List / Brake Fluid Pressure (0.04 MPa or more)

   ENGINE START REQUEST (ACC):
   
   

   Countermeasures and Related Areas	Start Conditions
   If the preceding vehicle starts moving but the Data List is OFF, inspect the following:  Dynamic radar cruise control system Engine stop and start ECU	When the vehicle is stopped with the all-speed dynamic radar cruise control system operating, the preceding vehicle starts to move or the user performs a resume operation (starts to move the vehicle)

   ENGINE START REQUEST (AIR SUSPENSION):
   
   

   Countermeasures and Related Areas	Start Conditions
   If the air suspension system is operating but the Data List is OFF, inspect the following:  Air suspension system	When condition not prohibited according to adaptive variable suspension system

   ENGINE START REQUEST (IPA):
   
   

   Countermeasures and Related Areas	Start Conditions
   If the advanced park (AP) is operating but the Data List is OFF, inspect the following:  Advanced park (AP) Engine stop and start ECU	When condition prohibited according to advanced park (AP)

   ENGINE START REQUEST (WELCAB):
   
   

   Countermeasures and Related Areas	Start Conditions
   If the welcab system is operating but the Data List is OFF, inspect the following:  Welcab system	When condition not prohibited according to Welcab system

   ENGINE START REQUEST (4WD AND REAR DIFFERENTIAL LOCK):
   
   

   Countermeasures and Related Areas	Start Conditions
   If the driving mode is being operated the Data List is OFF, inspect the following:  Rear differential lock Drive mode Snow Mode	Data List / Rear Differential Lock Operating Status (ON: Lock) Except NORMAL, ECO or COMFORT modes Snow mode ON

Result: 

A 

See step  6

1. Enter the following menus: Powertrain / Stop and Start / Utility / Vehicle Control History (RoB).

   Powertrain > Stop and Start > Utility 

   Tester Display
   Vehicle Control History (RoB)

2. Select a vehicle control history item to display the data from the time of control.
3. Check the output data.

   HINT: 

   • Checking the Freeze Frame Data allows the vehicle conditions at the time of detection to be confirmed.
   • As Vehicle Control History may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History data before performing any inspections.

   Result

   Result	Proceed to
   NO is displayed for Engine Start Fail in the vehicle control history	A
   Yes is displayed for Engine Start Fail in the vehicle control history	B

Result: 

A 

GO TO SFI SYSTEM (ROB CHART) 

Diagnostic trouble code chart :

Refer to DIAGNOSTIC TROUBLE CODE CHART [10/2023 - 11/2024] , or refer to DIAGNOSTIC TROUBLE CODE CHART [11/2024 - ]

Vehicle control history (RoB):

Refer to VEHICLE CONTROL HISTORY (RoB) [12/2021 - 11/2024] , or refer to VEHICLE CONTROL HISTORY (RoB) [11/2024 - ]

Result: 

B 

See step  7

1. Enter the following menus: Powertrain / Stop and Start / Utility / Vehicle Control History (RoB).

   Powertrain > Stop and Start > Utility 

   Tester Display
   Vehicle Control History (RoB)

2. Select a vehicle control history item to display the data from the time of control.
3. Check the output data.

   HINT: 

   • Checking the Freeze Frame Data allows the vehicle conditions at the time of detection to be confirmed.
   • As Vehicle Control History may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History data before performing any inspections.

   Result

   Result	Proceed to
   All recorded sections Starter Motor = OFF, and all recorded sections Engine Speed = 0 rpm HINT:  It is possible that the starter drive command is not being sent from the engine stop and start ECU.	A
   Starter Motor = ON for any sections, and all recorded sections Engine Speed = 0 rpm HINT:  It is possible that the drive command is being sent from the engine stop and start ECU but the starter itself is not moving.	B
   Engine Speed > 0 rpm for any sections HINT:  It is possible that cranking was achieved but the engine stopped.	C

Result: 

A 

REPLACE ENGINE STOP AND START ECU 

Refer to REMOVAL [10/2023 - ]

HINT: 

It is possible that there is a malfunction of the starter drive circuit inside the stop and start ECU.

Result: 

C 

See step  12

Result: 

B 

See step  8

1. Enter the following menus: Powertrain / Stop and Start / Utility / Vehicle Control History (RoB).

   Powertrain > Stop and Start > Utility 

   Tester Display
   Vehicle Control History (RoB)

2. Select a vehicle control history item to display the data from the time of control.
3. Check the output data.

   HINT: 

   • Checking the Freeze Frame Data allows the vehicle conditions at the time of detection to be confirmed.
   • As Vehicle Control History may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History data before performing any inspections.

   Result

   Result	Proceed to
   Cranking Time is 1.5 seconds or more HINT:  It is possible that there is an external malfunction outside of the stop and start ECU (drive circuit).	A
   Cranking Time is less than 1.5 seconds HINT:  It is possible that there is a malfunction in the stop and start ECU (drive circuit).	B

Result: 

B 

REPLACE ENGINE STOP AND START ECU 

Refer to REMOVAL [10/2023 - ]

Result: 

A 

See step  9

1. Disconnect the engine stop and start ECU connector.
2. Turn the ignition switch to ON.
3. Turn off any electrical loads.
4. Measure the voltage according to the value(s) in the table below.

   OK

   11 V or higher

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A25-1 (+B) - Body ground	Ignition switch ON	11 V or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  11

Result: 

OK 

See step  10

1. Enter the following menus: Powertrain / Stop and Start / Utility / Vehicle Control History (RoB).

   Powertrain > Stop and Start > Utility 

   Tester Display
   Vehicle Control History (RoB)

2. Select a vehicle control history item to display the data from the time of control.
3. Check the output data.

   HINT: 

   • Checking the Freeze Frame Data allows the vehicle conditions at the time of detection to be confirmed.
   • As Vehicle Control History may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History data before performing any inspections.
   • Depending on RoB detection timing, the minimum voltage from the previous startup will be stored for the Minimum Voltage (Cranking) and the Minimum Voltage (Starter Solenoid Engagement). For the battery condition at the start of the current driving cycle, see Battery Voltage.
   • When the value is 20 V, the value is being calculated.

   Result

   Result	Proceed to
   Battery voltage is 8.92 V or more	A
   Battery voltage is less than 8.92 V	B

Result: 

A 

INSPECT STARTER SYSTEM 

Refer to Starter Signal Circuit [10/2023 - ]

Result: 

B 

See step  11

1. Measure the voltage of the battery.

   Standard voltage

   11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

INSPECT STARTER SYSTEM 

Refer to Starter Signal Circuit [10/2023 - ]

Result: 

NG 

REPLACE BATTERY 

1. Enter the following menus: Powertrain / Stop and Start / Utility / Vehicle Control History (RoB).

   Powertrain > Stop and Start > Utility 

   Tester Display
   Vehicle Control History (RoB)

2. Select a vehicle control history to display the Cranking Time and Starter OFF Permission History (ECM) data from the time of control.
3. Check the output data.

   HINT: 

   • Checking the Freeze Frame Data allows the vehicle conditions at the time of detection to be confirmed.
   • As Vehicle Control History may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History data before performing any inspections.

   Result

   Result		Proceed to
   Cranking Time is less than 1.5 seconds	Starter OFF Permission History (ECM) is ON HINT:  It is possible that the ECM made a judgment of complete combustion and the ECM then stopped the starter.	A
   	Starter OFF Permission History (ECM) is OFF HINT:  It is possible that the engine stop and start ECU made a judgment of complete combustion and the engine stop and start ECU then stopped the starter.	B
   Cranking Time is 1.5 seconds or more HINT:  It is possible that the stop and start ECU did not stop the starter.	-	C

Result: 

A 

SFI SYSTEM (POOR STARTABILITY) 

Refer to Engine Difficult to Start [12/2021 - ]

HINT: 

Check whether the speed value of the EFI ECU is not a higher value than the original NE.

Result: 

C 

See step  17

Result: 

B 

See step  13

1. Enter the following menus: Powertrain / Stop and Start / Data List / Engine Speed and Engine Speed (ECM).

   Powertrain > Stop and Start > Data List 

   Tester Display
   Engine Speed
   Engine Speed (ECM)

2. Compare the Data List items displayed on the GTS.

   Result

   Result	Proceed to
   Engine Speed > Engine Speed (ECM) + 100 rpm	A
   None of the above conditions are met	B

Result: 

B 

See step  16

Result: 

A 

See step  14

1. Enter the following menus: Powertrain / Stop and Start / Utility / Vehicle Control History (RoB).

   Powertrain > Stop and Start > Utility 

   Tester Display
   Vehicle Control History (RoB)

2. Select a vehicle control history item to display the data from the time of control.
3. Check the data points in the data that was output.

   HINT: 

   • Checking the Freeze Frame Data allows the vehicle conditions at the time of detection to be confirmed.
   • As Vehicle Control History may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History data before performing any inspections.

   Result

   Result	Proceed to
   For each and all of the data points, Engine Speed > Engine Speed (ECM) + 100 rpm	A
   None of the above conditions are met	B

Result: 

A 

READ VALUE USING GTS (ENGINE SPEED) 

Refer to DTC P0335-62: Crankshaft Position Sensor "A" Signal Compare Failure [10/2023 - ]

Result: 

B 

See step  15

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Enter the following menus: Powertrain / Stop and Start / Active Test / Starter (Hood Close)

   Powertrain > Stop and Start > Active Test 

   Tester Display
   Starter(Hood Close)

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

   Refer to TERMINALS OF ECU [10/2023 - ]

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A25-21 (STA) - A25-6 (DGND)	Performing Active Test, while cranking.	6 to 14 V

3. Using an oscilloscope, measure the waveform immediately after starting.

   Item	Content
   Tester Connection	A25-21 (STA) ←→ A25-6 (DGND)
   Tool Setting	10 V/DIV, 200 ms./DIV
   Condition	During cranking

   OK

   Voltage and waveform both normal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Result

   Proceed to
   OK
   NG

Result: 

OK 

INSPECT ENGINE (SFI SYSTEM, POOR STARTABILITY) 

Refer to PROBLEM SYMPTOMS TABLE [08/2020 - ]

Result: 

NG 

REPLACE ENGINE STOP AND START ECU 

Refer to REMOVAL [10/2023 - ]

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Enter the following menus: Powertrain / Stop and Start / Active Test / Starter (Hood Close)

   Powertrain > Stop and Start > Active Test 

   Tester Display
   Starter(Hood Close)

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

   Refer to TERMINALS OF ECU [10/2023 - ]

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A25-21 (STA) - A25-6 (DGND)	Performing Active Test, while cranking.	6 to 14 V

3. Using an oscilloscope, measure the waveform immediately after starting.

   Item	Content
   Tester Connection	A25-21 (STA) ←→ A25-6 (DGND)
   Tool Setting	10 V/DIV, 200 ms./DIV
   Condition	During cranking

   OK

   Voltage and waveform both normal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Result

   Proceed to
   OK
   NG

Result: 

OK 

INSPECT ENGINE (SFI SYSTEM, POOR STARTABILITY) 

Refer to PROBLEM SYMPTOMS TABLE [08/2020 - ]

Result: 

NG 

REPLACE ENGINE STOP AND START ECU 

Refer to REMOVAL [10/2023 - ]

1. Enter the following menus: Powertrain / Stop and Start / Utility / Vehicle Control History (RoB).

   Powertrain > Stop and Start > Utility 

   Tester Display
   Vehicle Control History (RoB)

2. Select a vehicle control history item to display the data from the time of control.
3. Check the output data.

   HINT: 

   • Checking the Freeze Frame Data allows the vehicle conditions at the time of detection to be confirmed.
   • As Vehicle Control History may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History data before performing any inspections.

   Result

   Result	Proceed to
   When Starter Motor is ON, there is even 1 point at which Engine Speed < 300 rpm	A
   None of the above conditions are met	B

Result: 

A 

INSPECT STARTER SYSTEM 

Refer to Starter Signal Circuit [10/2023 - ]

Result: 

B 

See step  18

1. Check how long it took the engine to stall after turning the starter off.

   Result

   Result	Proceed to
   After starter turned off, engine immediately stalls. HINT:  Engine stalls within 2 seconds.	A
   After starter turned off, engine stalls after a time.	B

Result: 

A 

SFI SYSTEM (ENGINE DIFFICULT TO START) 

Refer to Engine Difficult to Start [12/2021 - ]

Result: 

B 

SFI SYSTEM (ENGINE STALLS) 

Refer to Engine Stalls [12/2021 - ]