STOP AND START SYSTEM, Diagnostic DTC:P1603

DTC Code	DTC Name
P1603	Engine Stall History

DESCRIPTION

If the engine stalls or engine start fails while the stop and start control is operating, DTC P1603 is stored. Using the GTS, the freeze frame data recorded the moment the DTC is stored can be read. Serviceability has been enhanced by enabling the cause of an engine stall or engine start failure which occurred while the stop and start control was operating to be checked using the freeze frame data.

DTC No.	DTC Detection Condition	Trouble Area
P1603	Both of the following conditions are met for 0.5 seconds or more (1 trip detection logic): Engine stopped by stop and start control and engine hood opened.1 Engine hood courtesy switch (hood lock assembly): Engine hood opened and mode changed to "stalled".2	Wire harness or connector Engine hood courtesy switch (Hood lock assembly) CAN communication system Airbag system SFI system Starter assembly Engine stop and start ECU
	Both of the following conditions are met for 0.5 seconds or more (1 trip detection logic): Engine stopped by stop and start control and collision or low battery voltage detected. Collision detection signal received from the airbag sensor assembly and mode changed to "stalled".*2
	Both of the following conditions are met for 0.5 seconds or more (1 trip detection logic): Engine being restarted by stop and start control and collision detected. Collision detection signal received from the airbag sensor assembly and mode changed to "stalled".*2
	Both of the following conditions are met for 0.5 seconds or more (1 trip detection logic): Engine being restarted by stop and start control and restart fails. Using the NE signal, complete combustion is identified 0.6 seconds after the engine stop judgment*3 was made or complete combustion does not occur even after the starter assembly has operated for a certain amount of time (NE signal is normal).
	Both of the following conditions are met for 0.5 seconds or more (1 trip detection logic): Engine being restarted by stop and start control and restart fails. Engine speed signal from the ECM not received via CAN communication (NE signal is abnormal*4).

*1: Only when the shift lever is in D
*2: The mode "stalled" represents a state in which engine restart is prohibited/canceled due to a collision being detected or the engine hood being opened and restart is not preferable. In this situation, "IG" is displayed for the Data List item [Stop&Start of Eng State]. If the mode changes to "IG", engine start by stop and start control is prohibited and the engine can only be started by operating the engine switch.
*3: Engine stop judgment is performed to judge whether the engine is stopped completely. The engine stop and start ECU judges that the engine is stopped when it does not receive an engine speed signal (NE signal) from the ECM for 0.6 seconds or more.
*4: The engine stop and start ECU stores DTC P0335.

WIRING DIAGRAM

Refer to Engine Hood Courtesy Switch Circuit Click here.
Refer to DTC P0617 Click here.

CAUTION / NOTICE / HINT

Note

Before replacing the engine stop and start ECU, read the number of starter operations and write it into a new engine stop and start ECU Click here.
After replacing the starter assembly, perform initialization of the number of starter operations stored in the engine stop and start ECU Click here.
When the starter assembly is replaced, "ST relay" and "ST NO. 2 relay" must be also replaced.
After replacing the engine stop and start ECU or air conditioning amplifier assembly, reset and perform learning of the air conditioning information in the engine stop and start ECU Click here.
After replacing the engine stop and start ECU or airbag sensor assembly, clear and calibrate the deceleration sensor zero point in the engine stop and start ECU Click here.
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips

If other DTCs are output, perform troubleshooting for this DTC first.
Unlike other DTCs that are stored due to a malfunction in parts, circuits or systems, DTC P1603 allows determination of a malfunctioning part according to problem symptoms and the freeze frame data related to a problem recognized by the customer. As this DTC may be stored due to an operation by the customer, it is not necessary to service the vehicle unless the customer recognized a problem. Clear DTCs and return the vehicle to the customer.
Using the GTS, read the freeze frame data before troubleshooting. System condition information is recorded as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.
Stop and Start Control Mode Transition:

*1: Engine stop conditions are met.
*2: Engine stop judgment is determined.
*3: Engine start conditions are met before the engine is judged as stopped.
*4: Engine start conditions are met.
*5: Engine determined to be started (engine speed reaches a specified rpm).
*6: Collision detected or engine hood opened and mode changed to "stalled".
*7: 0.6 seconds elapse after engine stop judgment is established.
*8: Engine is started using the engine switch.

PROCEDURE

CHECK DTC OUTPUT (SFI SYSTEM)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Trouble Codes

Read the DTCs.

Result
Result	Proceed to
SFI system DTCs are not output	A
SFI system starting malfunction circuit DTC is output and starter assembly does not operate	A
SFI system starting malfunction circuit DTC is output and starter assembly operates	B
DTCs other than SFI system starting malfunction circuit DTC are output	B

According to the display on the GTS, check the freeze frame data item [Cranking Time] in the sets of freeze frame data.
If the value of [Cranking Time] is approximately 3 seconds, the stop and start control system or starter system may be malfunctioning.
If the value of [Cranking Time] is small (approximately 0.5 seconds or less: the minimum value varies depending on the model), the SFI system may be malfunctioning.
The Data List item [Cranking Time] indicates the length of time starter operation is requested by the engine stop and start ECU. If the engine speed exceeds the specified value, the engine stop and start ECU cancels its start request.

GO TO SFI SYSTEM Click here

CHECK FREEZE FRAME DATA

Note

The freeze frame data is cleared when DTCs are cleared. Be sure to make a note of necessary data in advance.

Tech Tips

Using the time-series freeze frame data, confirm the freeze frame data recorded the moment the DTC was stored and after the DTC was stored. This information can be useful when troubleshooting.

According to the prompts on the GTS screen, read the time-series freeze frame data to confirm the vehicle conditions when an engine stall occurred while the stop and start control was operating.

Check the freeze frame data for engine stall history and engine start failure.

Result

GTS Display	Result	Proceed to
Engine Stall History during S&S (Hood Open)	Yes	A
Engine Stall History during S&S (Collision or Battery Low)	Yes	B
Engine Stall History during Engine Starting (Collision)	Yes	B
Engine Start Fail	Yes	C

CHECK VEHICLE CONDITION (COLLISION HISTORY) Click here

CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - ST, ST NO. 2 RELAY) Click here

READ VALUE USING GTS (HOOD COURTESY SWITCH)

Note

Before performing this step, check that the engine hood can be opened by pulling the hood lock control cable.

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Stop and Start / Data List / Hood Courtesy Switch.

According to the display on the GTS, read the Data List.

GTS Display	Condition	Normal Condition
Hood Courtesy Switch	Engine hood is closed	ON
Hood Courtesy Switch	Engine hood is open	OFF

Result
Result	Proceed to
NG	A
OK	B

USE SIMULATION METHOD TO CHECK Click here

INSPECT HOOD LOCK ASSEMBLY (ENGINE HOOD COURTESY SWITCH)
1. Remove the engine hood courtesy switch (hood lock assembly) Click here.
2. Inspect the engine hood courtesy switch (hood lock assembly) Click here.
NG
REPLACE HOOD LOCK ASSEMBLY Click here

OK

CHECK HARNESS AND CONNECTOR (ENGINE HOOD COURTESY SWITCH (HOOD LOCK ASSEMBLY) - BODY GROUND)

Disconnect the A2 engine hood courtesy switch (hood lock assembly) connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A2-1 (E) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - ENGINE HOOD COURTESY SWITCH (HOOD LOCK ASSEMBLY))

Disconnect the A2 engine hood courtesy switch (hood lock assembly) connector.
Disconnect the A77 engine stop and start ECU connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A77-7 (BNT1) - A2-2 (+)	Always	Below 1 Ω
A77-7 (BNT1) or A2-2 (+) - Body ground	Always	10 kΩ or higher

REPLACE ENGINE STOP AND START ECU Click here

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK VEHICLE CONDITION (COLLISION HISTORY)

Check if the vehicle was in a collision when the engine stalled.

Result
Result	Proceed to
Vehicle was not in collision when engine stalled	A
Vehicle was in collision when engine stalled	B

Tech Tips

When "Engine Stall History during S&S (Collision or Battery Low)" or "Engine Stall History during Engine Starting (Collision)" is stored:

This may have been stored because the vehicle was in a collision or a collision detection signal was input while the stop and start control was operating.

GO TO AIRBAG SYSTEM Click here

END (ENGINE STALLED BECAUSE COLLISION DETECTION SIGNAL IS RECEIVE)

CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - ST, ST NO. 2 RELAY)

Disconnect the A36 certification ECU (smart key ECU assembly) connector.
Disconnect the D72 park/neutral position switch assembly connector.
Disconnect the A75 ECM connector.
Disconnect the A77 engine stop and start ECU connector.
Remove the ST relay from engine room relay block and junction block assembly.
Remove the ST NO. 2 relay from engine room relay block and junction block assembly.
Remove the BBC NO. 1 fuse from engine room relay block and junction block assembly.
Remove the BBC NO. 2 fuse from engine room relay block and junction block assembly.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A77-21 (STA) - ST relay terminal 2	Always	Below 1 Ω
A77-23 (STA2) - ST NO. 2 relay terminal 2	Always	Below 1 Ω
A77-21 (STA) or ST relay terminal 2 - Body ground	Always	10 kΩ or higher
A77-23 (STA2) or ST NO. 2 relay terminal 2 - Body ground	Always	10 kΩ or higher
A76-1 (BIN2) - A77-21 (STA)	Always	10 kΩ or higher
A76-3 (BIN1) - A77-21 (STA)	Always	10 kΩ or higher
A76-1 (BIN2) - A77-23 (STA2)	Always	10 kΩ or higher
A76-3 (BIN1) - A77-23 (STA2)	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (ST, ST NO. 2 RELAY - BODY GROUND)

Remove the ST relay from engine room relay block and junction block assembly.
Remove the ST NO. 2 relay from engine room relay block and junction block assembly.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
ST relay terminal 1 - Body ground	Always	Below 1 Ω
ST NO. 2 relay terminal 1 - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (ST, ST NO. 2 RELAY - BATTERY)

Text in Illustration
*1	Engine Room Relay Block and Junction Block Assembly
*a	ST Relay Terminal
*b	ST NO. 2 Relay Terminal

Remove the ST relay from engine room relay block and junction block assembly.

Remove the ST NO. 2 relay from engine room relay block and junction block assembly.

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

Standard Voltage

Tester Connection	Condition	Specified Condition
ST relay terminal 5 - Body ground	Always	9.5 to 14 V
ST NO. 2 relay terminal 5 - Body ground	Always	9.5 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (STARTER ASSEMBLY - BATTERY)

Text in Illustration
*1	Starter Assembly
*a	F3-1 (B)

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

Standard Voltage

Tester Connection	Condition	Specified Condition
F3-1 (B) - Body ground	Always	9.5 to 14 V

Note

Before performing this step, check that the starter assembly connector F3 is not disconnected or loose.

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (STARTER ASSEMBLY - ST, ST NO. 2 RELAY)

Remove the ST relay from engine room relay block and junction block assembly.
Remove the ST NO. 2 relay from engine room relay block and junction block assembly.
Disconnect the D83 starter assembly connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
ST relay terminal 3 - D83-2 (SL1)	Always	Below 1 Ω
ST NO. 2 relay terminal 3 - D83-1 (SL2)	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

INSPECT ST, ST NO. 2 RELAY
1. Inspect the ST relay Click here.
2. Inspect the ST NO. 2 relay Click here.
NG
REPLACE RELAY (ST, ST NO. 2 RELAY)

OK
INSPECT STARTER ASSEMBLY
1. Inspect the starter assembly Click here.
OK
REPLACE ENGINE STOP AND START ECU Click here

NG
REPLACE STARTER ASSEMBLY Click here