STOP AND START STOP AND START SYSTEM After Engine Stops due to Stop and Start System, Engine does not Restart
DESCRIPTION
Perform this procedure when the engine does not restart after being stopped by the stop and start system.
Regarding explanations of the features of stop and start system control:
PROCEDURE
Check if the engine restarts after being stopped by the stop and start system.
- Result:
Result Proceed to When the vehicle is stopped, the engine does not restart when attempting to start-off. A Engine stall or similar action occurs during idling stop.
(meter display, etc.)B Idling stop continues even when an action* which should restart the engine is performed
*: Brake pedal is released, the shift lever is operated, etc.C
A
B
C
Based on the respective Data List item, troubleshoot the suspected areas which may prevent the ECM from creating engine start requests.
- HINT:
-
Depending on the vehicle, some of the items are not displayed.
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the engine is stopped by the stop and start system and an engine start request is not generated even though the brakes are operated, inspect the following items:
·
Stop Light switch assembly (ECM) ·
Stop Light switch assembly (ABS/VSC) ·
Master cylinder pressure sensor (brake control system) ·
Stop light switch circuit ·
Airbag sensor with ECU assembly (G sensor)
|
·
Data List / Stop Light SW (ECM) (OFF: Brake pedal fully released) ·
Data List / Stop Light SW (ABS/VSC) (OFF: Brake pedal fully released) ·
Data List / Master Cylinder Pressure* (Brake pedal released)
|
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the engine is stopped by the stop and start system and an engine start request is not generated even though the driver exited the vehicle, inspect the following items:
·
Driver side seat belt buckle switch circuit (DTC U014087 (Lost communication with (main body ECU (multiplex network body ECU)) ·
Front seat inner belt assembly (for driver side) ·
Driver side door courtesy switch circuit (DTC U014087 (Lost communication with main body ECU (multiplex network body ECU)) ·
Driver door courtesy switch circuit |
·
Data List / Driver Courtesy Switch Signal (ON: Driver side door open) ·
The driver seat belt is unfastened. |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the engine is stopped by the stop and start system and an engine start request is not generated even though the shift lever is moved, inspect the following items:
·
Shift lever assembly ·
ECM (or transmission control ECU) |
Data List / Shift Position
(Other than D or P) |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the engine is stopped by the stop and start system and an engine start request is not generated even though the stop and start system cancel switch (combination switch assembly) is pushed, inspect the following items:
·
Stop and start system cancel switch (combination switch assembly) circuit |
Data List / Stop&Start Cancel Switch
(ON: Stop and start system cancel switch (combination switch assembly) pressed) |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the engine is stopped by the stop and start system and an engine start request is not generated even though the steering wheel is operated, inspect the following items:
·
Steering sensor ·
Steering system ·
Engine stop and start ECU |
Data List / Steering Angle
(The steering wheel is turned 25 deg or more since the engine was stopped by the stop and start system.) |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the engine is stopped by the stop and start system and an engine start request is not generated even though the clutch pedal is depressed, inspect the following items:
·
Clutch upper switch ·
Engine stop and start ECU |
OFF: Clutch pedal depressed |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the engine is stopped by the stop and start system and an engine start request is not generated even though the clutch pedal is fully depressed, inspect the following items:
·
Clutch lower switch ·
Engine stop and start ECU |
ON: Clutch pedal depressed |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
·
Check that the stop and start operation conditions related to the air conditioning system are met. ·
When the engine is stopped by the stop and start system and an engine start request is not generated even though all conditions for the air conditioning system to generate a start request are met, inspect the following items: - Air conditioning system |
·
Timer in the air conditioning amplifier assembly runs out ·
Both of the following conditions are met: -
Blower Switch: ON -
Evaporator temperature exceeds threshold value (threshold value varies with temperature, humidity and amount of solar radiation) ·
Any of the following conditions are met: -
A/C switch, blower switch: OFF to ON -
Defogger switch: OFF to ON -
Blower switch turned off during auto control or blower mode changed to manual -
Changes from stop and start system priority control to normal system control |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the engine is stopped by the stop and start system and an engine start request is not generated even though the accelerator pedal is depressed, inspect the following items:
·
Accelerator pedal sensor assembly ·
ECM (or transmission control ECU) |
Data List / Idle
(OFF: Accelerator pedal depressed) |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the engine is stopped by the stop and start system and an engine start request is not generated even though the brake pedal is further depressed or the brake pedal is pumped, inspect the following items:
·
Brake booster vacuum insufficient ·
Vacuum sensor assembly ·
Brake booster assembly ·
Master cylinder pressure sensor (brake control system) ·
Engine stop and start ECU |
Data List / Brake Boost Pressure
(Brake booster vacuum insufficient (Under 37.5 kPa (0.4 kg/cm2, 5 psi)) (Brake booster vacuum changes in accordance with brake fluid pressure (brake pedal effort)) |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the engine is stopped by the stop and start system and an engine start request is not generated even though the ignition switch or engine switch is operated, inspect the following items:
·
Certification ECU (smart key ECU assembly)*1 ·
Engine switch*1 ·
Ignition or starter switch assembly*2 ·
Engine stop and start ECU *1: w/ Smart Entry and Start System *2: w/o Smart Entry and Start System |
Starter operating
·
When Data List "Starter Type" is "Tandem Starter": -
Data List / Starter Motor (ON: Cranking) -
Data List / Starter (ON: Starter pinion operating) ·
When Data List "Starter Type" is "Other than Tandem Starter": Data List / Starter (ON: Starter operating) |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the shift lever is in P, the engine is stopped by the stop and start system, and an engine start request is not generated even though the brake pedal is depressed, inspect the following items:
·
Shift lever assembly ·
Stop light switch circuit ·
ECM (or transmission control ECU) ·
Engine stop and start ECU ·
Skid control ECU (brake actuator assembly) |
·
Data List / Stop&Start of Engine State (Stop: Engine stopped (by stop and start control)) ·
Data List / Shift Position (P) ·
Data List / Stop Light SW (ABS/VSC) (ON: Brake pedal depressed → OFF: Brake pedal released → ON: Brake pedal depressed) ·
Data List / Stop Light SW (ECM) (ON: Brake pedal depressed → OFF: Brake pedal released → ON: Brake pedal depressed) ·
Data List / Master Cylinder Pressure* (40 kPa (0.4 kgf/cm2, 6 psi) or higher)
|
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the preceding vehicle has started off but the respective Data List item indicates OFF, inspect the following items:
·
Dynamic radar cruise control system ·
Engine stop and start ECU |
·
When the dynamic radar cruise control (w/ full speed range following function) system is operating and the vehicle is stopped, the vehicle is restarted or the preceding vehicle starts off. ·
Operation of the stop and start system is prohibited due to the dynamic radar cruise control system. |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the air suspension system or side left up seat system is being operated but the respective Data List item indicates OFF, inspect the following items:
·
Air suspension system ·
Side left up seat system |
Operation of the stop and start system is prohibited due to the side left up seat system. |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the intelligent parking assist system is being operated but the respective Data List item indicates OFF, inspect the following items:
·
Intelligent parking assist system ·
Engine stop and start ECU |
Operation of the stop and start system is prohibited due to the intelligent parking assist system. |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When the side left up seat system is being operated but the respective Data List item indicates OFF, inspect the following items:
·
Side left up seat system |
Operation of the stop and start system is prohibited due to the side left up seat system. |
| Action to be Taken and Suspected Area | Conditions |
|---|---|
| When drive mode is being operated but the respective Data List item indicates OFF, inspect the following items:
·
Rear differential lock ·
Drive mode ·
Snow mode |
·
Data List / Rear Differential Lock Operation State (ON: Lock) ·
Other than COMFORT, ECO or NORMAL mode ·
ON: Snow mode on |
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Stop and Start / Trouble Codes.
Read the DTCs.
- Powertrain > Stop and Start > Trouble Codes
- 50001 392
- Result:
Result Proceed to DTC P160300 is output A DTC P160300 is not output B
A
B
Check if starter motor operation sounds can be heard after the engine is stopped by the stop and start system.
- Result:
Result Proceed to Starter motor operation sounds can be heard (for less than 3 seconds)*1 A Starter motor operation sounds can be heard (for 3 seconds or more)*2 B Starter motor operation sounds cannot be heard*3 C
- HINT:
- ·
*1: After combustion occurs, the engine stalls due to insufficient engine speed.
·*2: The engine continues to crank due to abnormal combustion.
·*3: The starter motor does not operate.
A
Confirm how quickly the engine stalls after the starter motor stops.
- Result:
Result Proceed to After the starter motor stops, the engine stalls immediately (within approximately 2 seconds). Engine Difficult to Start:
(
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After the starter motor stops, the engine continues to run before stalling. Engine Stalls
Click here(201906,999999,_51,_080777,_0393969,RM100000001I1V1,)
B
C
Confirm if initial combustion occurs during cranking.
- Result:
Result Proceed to Initial combustion occurs during cranking but the engine fails to start A Initial combustion does not occur during cranking B
A
B
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Stop and Start / Trouble Codes.
Read the DTCs.
- Powertrain > Stop and Start > Trouble Codes
- 50001 392
- Result:
Result Proceed to DTC P160300 is output A DTC P160300 is not output B
A
Check the Freeze Frame Data recorded at the time the DTCs were stored.
- Result:
Tester Display Result Suspected Cause Action to be Taken Engine Stall History during Stop&Start (Hood Open) ON Engine hood was opened during idling stop Refer to "Engine Hood Courtesy Switch Circuit"
(201906,999999,_51,_080774,_0393362,RM100000001HXIG,)
Engine Stall History during Stop&Start (Collision or Battery Voltage Low) ON A collision or low battery voltage was detected during idling stop Refer to the troubleshooting procedure for DTC P160300 (from step 3).
(201906,999999,_51,_080774,_0393362,RM100000001HXI5_04_0001,P160300)
B
- HINT:
-
If engine stall is not due to the SFI system, the cause may be due to an unstable power source to the engine stop and start ECU.