Toyota Corolla Cross: Starter Signal Circuit

Toyota Corolla Cross (2022-2024) Service Manual / Engine & Hybrid System / Stop And Start / Stop And Start System / Starter Signal Circuit

DESCRIPTION

The engine stop and start ECU uses its internal starter circuit to drive the starter drive relay (ST relay) and operate the starter.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

When the engine stop and start ECU is replaced, read the number of starter operations before replacement and record this number to the new engine stop and start ECU after replacement.
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When the engine stop ECU has been replaced, perform external backup boost converter (Eco run vehicle converter assembly) existence learning.
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After replacing the engine stop and start ECU or air conditioner amplifier assembly, perform initialization/learning of the air conditioner information for the engine stop and start ECU.
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When the starter assembly is replaced, the number of starter operations stored in the engine stop and start ECU must be reset.
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When the engine stop and start ECU or oil pump with motor assembly is replaced, check the oil pump with motor assembly.
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When the starter assembly is replaced, "ST relay" must be also replaced.
Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

For wire harness and connector inspection procedures and precautions, refer to

PROCEDURE

1.	CHECK CRANKING

(a) Turn the ignition switch START and check that the engine cranks.

Result	Proceed to
Engine cranks	A
Engine does not crank	B

GO TO STEP 15

2.	PERFORM ACTIVE TEST USING GTS (STARTER(HOOD CLOSE))

(a) Using the GTS, perform Active Test.

Powertrain > Stop and Start > Active Test

Tester Display
Starter(Hood Close)

(b) Check whether the engine cranks while the Active Test "Starter(Hood Close)" is being performed.

NOTICE:

The Active Test "Starter(Hood Close)" is stopped automatically 3 seconds after the starter assembly begins operating.

Standard:

Engine cranks

Result	Proceed to
Engine cranks	A
Engine does not crank	B

GO TO STEP 14

3.	CHECK VEHICLE CONTROL HISTORY (RoB) (ENGINE CONTROL SYSTEM)

(a) Enter the following menus.

Powertrain > Engine > Utility

Tester Display
Vehicle Control History (RoB)

(b) Check the vehicle control history (RoB).

Result	Proceed to
Engine control system Vehicle Control History (RoB) is not output	A
Engine Difficult to Start is output	B
Result other than Engine Difficult to Start is output	C

HINT:

If the value of "Cranking Time" is approximately 1.5 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 engine control 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 STEP 6

GO TO ENGINE CONTROL SYSTEM

4.	CHECK VEHICLE CONTROL HISTORY (RoB)

(a) Enter the following menus.

Powertrain > Stop and Start > Utility

Tester Display
Vehicle Control History (RoB)

(b) Select a vehicle control history (RoB) item to display the data from the time of control.

Tester Display	Result	Proceed to
Engine Stall History during Stop&Start (Collision or Battery Voltage Low)	Yes	A
Engine Stall History during Engine Starting (Collision)	Yes	A
Engine Start Fail	Yes	B
Vehicle control history (RoB) item is not output or No is displayed for the results of all of the freeze frame data above		B

GO TO STEP 7

5.	CHECK VEHICLE CONDITION (COLLISION HISTORY)

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

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

HINT:

When "Engine Stall History during Stop&Start (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 stop and start control was operating.

END (ENGINE STALLED BECAUSE COLLISION DETECTION SIGNAL WAS RECEIVED)

GO TO AIRBAG SYSTEM

6.	CHECK VEHICLE CONTROL HISTORY (RoB) (ENGINE CONTROL SYSTEM)

(a) Enter the following menus.

Powertrain > Engine > Utility

Tester Display
Vehicle Control History (RoB)

(b) Select Engine Difficult to Start from the Vehicle Control History (RoB) to display the data from the time of control.

HINT:

Checking the freeze frame data allows the vehicle conditions at the time of detection to be confirmed.
As Vehicle Control History (RoB) may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History (RoB) data before performing any inspections.

Result	Proceed to
Engine speed does not rise to approximately 300 rpm (Starter does not rotate)	A
Engine speed rises to approximately 300 rpm (Starter rotates)	B

GO TO STEP 4

GO TO ENGINE CONTROL SYSTEM

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

(a) Disconnect the I223 certification ECU (smart key ECU assembly) connector.*1

*1: w/ Smart Key System

(b) Disconnect the C62 park/neutral position switch assembly connector.

(d) Disconnect the A169 engine stop and start ECU connector.

(e) Remove the ST relay from the NO. 1 engine room relay block.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A169-21 (STA) - ST relay terminal 2	Always	Below 1 Ω
A169-21 (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

8.	CHECK HARNESS AND CONNECTOR (ST RELAY - BODY GROUND)

(a) Remove the ST relay from the NO. 1 engine room relay block.

(b) 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

9.	CHECK HARNESS AND CONNECTOR (ST RELAY - AUXILIARY BATTERY)

(a) Remove the ST relay from the NO. 1 engine room relay block.

(b) 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

*1	NO. 1 Engine Room Relay Block
*a	ST Relay Terminal

REPAIR OR REPLACE HARNESS OR CONNECTOR

10.	CHECK HARNESS AND CONNECTOR (STARTER ASSEMBLY - AUXILIARY BATTERY)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
C137-1 (B) - Body ground	Always	9.5 to 14 V

NOTICE:

Before performing this step, check that the starter assembly connector C137 is not disconnected or loose.

*1	Starter Assembly
*a	C137-1 (B)

REPAIR OR REPLACE HARNESS OR CONNECTOR

11.	CHECK HARNESS AND CONNECTOR (ST RELAY - STARTER ASSEMBLY)

(a) Remove the ST relay from the NO. 1 engine room relay block.

(b) Disconnect the C135 starter assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
ST relay terminal 3 - C135-2 (ST)	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

12.	INSPECT RELAY (ST RELAY)

Click here

REPLACE RELAY (ST RELAY)

13.	INSPECT STARTER ASSEMBLY

Click here

REPLACE ENGINE STOP AND START ECU

HINT:

If arriving at this item from the item "Drive command is being sent from the engine stop and start ECU but the starter itself is not moving" of "After Engine Stops due to Stop and Start System, Engine does not Restart" in Stop and Start / Stop and Start System / Problem Symptoms Table, go to SIMULATION METHOD.

REPLACE STARTER ASSEMBLY

14.	CHECK HARNESS AND CONNECTOR (STA SIGNAL)

(a) Disconnect the engine stop and start ECU connectors.

Front view of wire harness connector

(to Engine Stop and Start ECU)

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

Click here

Standard Voltage:

Tester Connection	Condition	Specified Condition
A169-21 (STA) - A169-6 (DGND)	Cranking commanded via Active Test item Starter(Hood Close)	6 to 14 V

HINT:

The Active Test "Starter" is stopped automatically 3 seconds after the starter assembly begins operating.

REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE STOP AND START ECU - ST RELAY)

REPLACE ENGINE STOP AND START ECU

HINT:

15.	PERFORM ACTIVE TEST USING GTS (STARTER(HOOD CLOSE))

(a) Using the GTS, perform Active Test.

Powertrain > Stop and Start > Active Test

Tester Display
Starter(Hood Close)

(b) Check whether the engine cranks while the Active Test "Starter(Hood Close)" is being performed.

NOTICE:

The Active Test "Starter(Hood Close)" is stopped automatically 3 seconds after the starter assembly begins operating.

Standard:

Engine cranks

Result	Proceed to
Engine cranks	A
Engine does not crank	B

GO TO STEP 26

16.	READ VALUE USING GTS (NEUTRAL SWITCH)

(a) In accordance with the display on the GTS, read the Data List.

Powertrain > Stop and Start > Data List

Tester Display
Neutral Switch

OK:

Tester Display	Condition	Normal Condition
Neutral Switch	Shift lever in P or N	ON
Neutral Switch	Shift lever not in P or N	OFF

Result	Proceed to
OK (w/ Smart Key System)	A
OK (w/o Smart Key System)	B
NG	C

GO TO STEP 19

GO TO STEP 21

17.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ENGINE STOP AND START ECU)

(a) Disconnect the C62 park/neutral position switch assembly connector.

(b) Disconnect the I223 certification ECU (smart key ECU assembly) connector.

(d) Disconnect the A47 ECM connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
I223-10 (STAR) - A169-17 (CLL)	Always	Below 1 Ω
I223-10 (STAR) - C62-4 (B)	Always	Below 1 Ω
I223-10 (STAR) - Body ground	Always	10 kΩ or higher
A169-17 (CLL) - Body ground	Always	10 kΩ or higher
C62-4 (B) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

18.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (STAR SIGNAL)

(a) Disconnect A169 the engine stop and start ECU connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A169-17 (CLL) - Body ground	Engine started using ignition switch (ignition switch turned to START)	9.5 to 14 V

SIMULATION METHOD TO CHECK

GO TO SMART KEY SYSTEM (START FUNCTION)

19.	CHECK HARNESS AND CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - ENGINE STOP AND START ECU)

(a) Disconnect the C62 park/neutral position switch assembly connector.

(b) Disconnect the I12 Ignition or Starter Switch Assembly connector.

(d) Disconnect the A47 ECM connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
I12-5 (ST1) - A169-17 (CLL)	Always	Below 1 Ω
I12-5 (ST1) - C62-4 (B)	Always	Below 1 Ω
I12-5 (ST1) - Body ground	Always	10 kΩ or higher
A169-17 (CLL) - Body ground	Always	10 kΩ or higher
C62-4 (B) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

20.	CHECK IGNITION OR STARTER SWITCH ASSEMBLY (ST1 SIGNAL)

(a) Disconnect A169 the engine stop and start ECU connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A169-17 (CLL) - Body ground	Engine started using ignition switch (ignition switch turned to START)	9.5 to 14 V

SIMULATION METHOD TO CHECK

REPAIR OR REPLACE HARNESS OR CONNECTOR

21.	CHECK VEHICLE SPECIFICATION

(a) Check the vehicle specification,

Result	Proceed to
for 2WD	A
for AWD	B

GO TO STEP 24

22.	INSPECT PARK/NEUTRAL POSITION SWITCH

Click here

REPLACE PARK/NEUTRAL POSITION SWITCH

23.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ST RELAY)

(a) Disconnect the I223 certification ECU (smart key ECU assembly) connector.

(b) Remove the ST relay from the NO. 1 engine room relay block.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I223-10 (STAR) - ST relay terminal 1	Shift lever in P or N	Below 1 Ω
I223-3 (STA) - Body ground	Shift lever not in P or N	10 kΩ or higher

REPLACE ENGINE STOP AND START ECU

HINT:

REPLACE PARK/NEUTRAL POSITION SWITCH

24.	INSPECT PARK/NEUTRAL POSITION SWITCH

Click here

REPLACE PARK/NEUTRAL POSITION SWITCH

25.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ST RELAY)

(a) Disconnect the I223 certification ECU (smart key ECU assembly) connector.

(b) Remove the ST relay from the NO. 1 engine room relay block.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I223-10 (STAR) - ST relay terminal 1	Shift lever in P or N	Below 1 Ω
I223-3 (STA) - Body ground	Shift lever not in P or N	10 kΩ or higher

REPLACE ENGINE STOP AND START ECU

HINT:

REPLACE PARK/NEUTRAL POSITION SWITCH

26.	CHECK HARNESS AND CONNECTOR (STA SIGNAL)

(a) Disconnect the A169 engine stop and start ECU connector.

Front view of wire harness connector

(to Engine Stop and Start ECU)

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

Click here

Standard Voltage:

Tester Connection	Condition	Specified Condition
A169-21 (STA) - A169-6 (DGND)	Engine start	6 to 14 V

Result	Proceed to
OK	A
NG	B

GO TO STEP 32

27.	INSPECT RELAY (ST RELAY)

Click here

REPAIR OR REPLACE HARNESS OR CONNECTOR

28.	CHECK HARNESS AND CONNECTOR (ST RELAY - AUXILIARY BATTERY)

(a) Remove the ST relay from the NO. 1 engine room relay block.

(b) 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

*1	NO. 1 Engine Room Relay Block.
*a	ST Relay Terminal

REPAIR OR REPLACE HARNESS OR CONNECTOR

29.	CHECK HARNESS AND CONNECTOR (ST RELAY - STARTER ASSEMBLY)

(a) Remove the ST relay from the NO. 1 engine room relay block.

(b) Disconnect the C135 starter assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
ST relay terminal 3 - C135-2 (ST)	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

30.	CHECK HARNESS AND CONNECTOR (ST RELAY - BODY GROUND)

(a) Remove the ST relay from the NO. 1 engine room relay block.

(b) 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

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

(a) Disconnect the I223 certification ECU (smart key ECU assembly) connector.*1

*1: w/ Smart Key System

(b) Disconnect the C62 park/neutral position switch assembly connector.

(d) Disconnect the A169 engine stop and start ECU connector.

(e) Remove the ST relay from the NO. 1 engine room relay block.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A169-21 (STA) - ST relay terminal 2	Always	Below 1 Ω
A169-21 (STA) - Body ground	Always	10 kΩ or higher
ST relay terminal 2 - Body ground	Always	10 kΩ or higher

REPLACE STARTER ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

32.	CHECK HARNESS AND CONNECTOR (POWER SUPPLY CIRCUIT)

(a) Disconnect the A168, A169 and I230 engine stop and start ECU connectors.

Front view of wire harness connector

(to Engine Stop and Start ECU)

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

Click here

Standard Voltage:

Tester Connection	Condition	Specified Condition
A168-3 (BIN1) - Body ground	Always	9.5 to 14 V
A168-1 (BIN2) - Body ground	Always	9.5 to 14 V

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

Click here

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A169-1 (+B) - Body ground	Ignition switch ON	9.5 to 14 V
I230-18 (IGP) - Body ground	Ignition switch ON	9.5 to 14 V
I230-21 (IGR) - Body ground	Ignition switch ON	9.5 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Disconnect the A168 and A169 engine stop and start ECU connectors.

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

Click here

Standard Resistance:

Tester Connection	Condition	Specified Condition
A168-2 (GND2) - Body ground	Always	Below 1 Ω
A168-8 (GND1) - Body ground	Always	Below 1 Ω
A169-6 (DGND) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Disconnect the I223 certification ECU (smart key ECU assembly) connector.*1

*1: w/ Smart Key System

(b) Disconnect the C62 park/neutral position switch assembly connector.

(d) Disconnect the A169 engine stop and start ECU connector.

(e) Remove the ST relay from the NO. 1 engine room relay block.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A169-21 (STA) - ST relay terminal 2	Always	Below 1 Ω
A169-21 (STA) - Body ground	Always	10 kΩ or higher
ST relay terminal 2 - Body ground	Always	10 kΩ or higher

REPLACE ENGINE STOP AND START ECU

HINT:

REPAIR OR REPLACE HARNESS OR CONNECTOR

SEE MORE:

Inspection

INSPECTION PROCEDURE 1. INSPECT FRONT DOOR AMBIENT LIGHT LH (FRONT DOOR TRIM BOARD SUB-ASSEMBLY LH) (a) Check the illumination. (1) Apply auxiliary battery voltage to the front door ambient light LH (front door trim board sub-assembly LH) and check that the light illuminates. OK:

Installation

INSTALLATION CAUTION / NOTICE / HINT COMPONENTS (INSTALLATION) Procedure Part Name Code 1 REAR AXLE HUB AND BEARING ASSEMBLY 42450B - - 2 INSTALL

Toyota Corolla Cross: Starter Signal Circuit

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SEE MORE:

Inspection

Installation