STOP AND START SYSTEM, Diagnostic DTC:P1603

DTC Code	DTC Name
P1603	Engine Stall History

DESCRIPTION

If the engine stalls or fails to start while stop and start control is operating, DTC P1603 will be 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 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 opened1 Engine hood courtesy switch (hood lock assembly): Engine hood opened and mode changed to "stalled"2 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 center 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 judgment3 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). Detection Conditions: Always Sensors/components used for detection: engine hood courtesy switch (hood lock assembly), neutral position sensor (neutral position switch), center airbag sensor assembly, battery, crank position sensor, STA signal circuit, ECM	Wire harness or connector Engine hood courtesy switch (hood lock assembly) CAN communication system Vehicle stability control system ECD system Starter assembly Engine stop and start ECU

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

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 center 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).

Detection Conditions: Always
Sensors/components used for detection: engine hood courtesy switch (hood lock assembly), neutral position sensor (neutral position switch), center airbag sensor assembly, battery, crank position sensor, STA signal circuit, ECM

Wire harness or connector
Engine hood courtesy switch (hood lock assembly)
CAN communication system
Vehicle stability control system
ECD system
Starter assembly
Engine stop and start ECU

*1: Driving shift position only
*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 ignition or starter switch assembly (w/o Entry and Start System) or push start switch (w/ Entry and Start System).
*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" 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 yaw rate sensor, perform deceleration sensor zero point clear and calibration Click here.
Inspect the fuses for circuits related to this system before performing the following 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 Click here.
Causes of engine stall or engine start failure while the engine is stopped by stop and start control:

If the engine hood is opened while the engine is stopped by stop and start control, the engine will stall.

The number of engine stalls due to the engine hood being opened while the engine is stopped by stop and start control is stored in the engine stall history.

If the engine hood is opened with the clutch pedal fully depressed while the engine is stopped by stop and start control, the engine will restart without stalling.

If a collision detection signal is received from the yaw rate sensor while the engine is stopped by stop and start control, the engine will stall.
If a collision detection signal is received from the yaw rate sensor while the engine is restarted by stop and start control, the engine will stall.
If low battery voltage is detected while the engine is stopped by stop and start control, the engine will stall.
If any problems that cause engine start failure and are not indicated by DTCs occur while the engine is stopped by stop and start control, the engine will not start.

PROCEDURE

CHECK DTC OUTPUT (ECD SYSTEM)

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

Read the DTCs.

Result
Result	Proceed to
No ECD system DTCs are output	A
Starter assembly does not operate	A
Starter assembly operates (for 1WW)	B
Starter assembly operates (for 2WW)	C
ECD system DTCs are output (for 1WW)	D
ECD system DTCs are output (for 2WW)	E

GO TO ECD SYSTEM Click here

GO TO DIAGNOSTIC TROUBLE CODE CHART 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 Click here.

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 Voltage 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 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 ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Stop and Start / Data List / Hood Courtesy Switch.

Read the value displayed on the GTS when the engine hood is opened and closed.

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

USE SIMULATION METHOD TO CHECK Click here

INSPECT ENGINE HOOD COURTESY SWITCH (HOOD LOCK ASSEMBLY)
1. 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 A33 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
A33-1 - 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 A80 engine stop and start ECU connector.
Disconnect the A33 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
A80-7 (BNT1) - A33-2	Always	Below 1 Ω
A80-7 (BNT1) - Body ground	Always	10 kΩ or higher
A33-2 - 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 in collision when engine stalled	A
Vehicle was not in collision when engine stalled (Freeze Frame Data "Engine Stall History during Engine Starting (Collision)" Yes)	B
Vehicle was not in collision when engine stalled (Freeze Frame Data "Engine Stall History during S&S (Collision or Battery Voltage Low)" Yes)	C

Tech Tips

When "Engine Stall History during S&S (Collision or Battery Voltage 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.
When "Engine Stall History during S&S (Collision or Battery Voltage Low)" is detected: This may have been stored because the battery was discharged and the voltage dropped while the stop and start control was operating. (e.g.: The gear was changed to any of the drive gears without the clutch pedal being depressed while the engine was stopped by stop and start control and the vehicle was left as is.)

END (ENGINE STALLED BECAUSE COLLISION DETECTION SIGNAL WAS RECEIVED)

GO TO AIRBAG SYSTEM Click here

CHECK BATTERY VOLTAGE

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

Standard Voltage

Tester Connection	Switch Condition	Specified Condition
Positive (+) battery terminal - Negative (-) battery terminal	Ignition switch ON	11 to 14 V

Result
Result	Proceed to
OK	A
NG (for 1WW)	B
NG (for 2WW)	C

GO TO CHARGING SYSTEM Click here

CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - BATTERY)

Text in Illustration

*a
Front view of wire harness connector

(to Engine Stop and Start ECU)

Disconnect the engine stop and start ECU connector.

Text in Illustration
*a	Front view of wire harness connector (to Engine Stop and Start ECU)

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

Standard Voltage

Tester Connection	Condition	Specified Condition
A79-7 (BIN) - Body ground	Always	9.5 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - BODY GROUND)

Disconnect the A79 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
A79-8 (GND) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (NEGATIVE (-) BATTERY TERMINAL - BODY GROUND)

Disconnect the negative (-) battery terminal.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
Negative (-) battery terminal - Body ground	Always	Below 1 Ω

REPLACE ENGINE STOP AND START ECU Click here

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - ST RELAY)

w/ Entry and Start System:

Disconnect the power management control ECU connector.
Disconnect the A80 engine stop and start ECU connector.
Disconnect the ECM connector.
Disconnect the clutch start switch assembly connector.
Remove the ST relay from the No. 1 relay block assembly.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A80-21 (STA) - ST relay terminal 2	Always	Below 1 Ω
A80-21 (STA) - Body ground	Always	10 kΩ or higher
ST relay terminal 2- Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (ST RELAY - BODY GROUND)

Remove the ST relay from the No. 1 relay 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

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (ST RELAY - BATTERY)

Text in Illustration
*1	No. 1 Relay Block Assembly
*2	ST Relay Terminal

Remove the ST relay from the No. 1 relay 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

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (STARTER ASSEMBLY - BATTERY)

Note

Before performing this step, check that the starter assembly connector R3 is not disconnected or loose.

Text in Illustration
*1	Starter Assembly
*2	R3-1 Terminal

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

Standard Voltage

Tester Connection	Condition	Specified Condition
R3-1 - Body ground	Always	9.5 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (ST RELAY - STARTER ASSEMBLY)

Remove the ST relay from the No. 1 relay block assembly.
Disconnect the B97 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 - B97-1	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

INSPECT RELAY (ST RELAY)
1. Inspect the ST relay.
  - for 1WW: Click here
  - for 2WW: Click here
NG
REPLACE RELAY (ST RELAY)

OK

INSPECT STARTER ASSEMBLY

Inspect the starter assembly.

for 1WW: Click here
for 2WW: Click here

Result
Result	Proceed to
OK	A
NG (for 1WW)	B
NG (for 2WW)	C

REPLACE ENGINE STOP AND START ECU Click here

REPLACE STARTER ASSEMBLY Click here