Inspection steps

WARNING: This page is about a different car, the 2018 Subaru BRZ. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION:

Some functions of the entry & start system (entry function) use the LIN communication system and the CAN communication system. Inspect the communication function by referring to "How to troubleshoot" (refer to HOW TO PROCEED WITH TROUBLESHOOTING ). Confirm that the communication system is functioning properly before proceeding to repair the entry & start system (entry function).
Before replacing the collation ECM (smart key ECM ASSY), refer to "entry & start system (entry function)". (Refer to ENTRY & START SYSTEM (ENTRY FUNCTION) )
Check if the electrical key transmitter SUB-ASSY is inside the vehicle.
Before proceeding with the inspection procedure, check that the DTC B1242 (wireless door lock control) is not output. (Refer to DTC CHECK/CLEAR )
Before performing the following inspection steps, check the fuses related to this system.
Even if you want to check the entry lock operation several times, the setting does not allow you to perform the lock operation more than twice in a row. To perform the entry lock operation more than twice, you have to unlock a door once (you may use any type of unlock operation). This limitation applies only to the entry lock operation. A wireless lock or other types of lock operations can be performed any number of times without any limitations.
After the repair work is complete, perform the "DTC output check operation" to confirm that the DTC is not output again.
The door control receiver is supplied 5 volts of power from the collation ECM.

Check the battery voltage.
1. Measure the voltage of the vehicle battery. Standard voltage: 11 to 14V
  NOTE: You can check if the vehicle battery is discharged by operating the horn. If the voltage is 11V or less, charge or replace the vehicle battery before performing the operation.
DTC check
1. Using the mechanical key integrated into the electrical key transmitter SUB-ASSY, open the driver's door.
2. Connect the SSM4 and check the DTC. (Refer to DTC CHECK/CLEAR )
  Criteria: No DTC is output
  
  OK: Go to next step
  
  NG: Go to "List of diagnostic codes" (refer to DIAGNOSTIC TROUBLE CODE CHART ).
Check the power door lock control system.
1. Operate the door control switch on the driver's side power window regulator master switch ASSY, and check if the door locks or unlocks properly according to the switch operation you have performed.
  Criteria: The door lock operation is performed properly.
  
  OK: Go to next step
  
  NG: Go to "Power door lock control system".

Check the electrical key transmitter SUB-ASSY.

Check if an electrical key transmitter SUB-ASSY registered to another vehicle is present.

RESULT DESCRIPTION

Result	Go to
An electrical key transmitter SUB-ASSY registered to another vehicle is not present.	A
An electrical key transmitter SUB-ASSY registered to another vehicle is present.	B

Go to next step
Go to Step 6.

Register a new electrical key transmitter SUB-ASSY.
1. Register a new electrical key transmitter SUB-ASSY. (Refer to the "Registration manual for immobilizer")
Check the entry door lock operation.
1. Using another electrical key transmitter SUB-ASSY registered to the vehicle, check if an entry lock/unlock operation can be performed 2 or more times in a row.
  Criteria: The entry lock/unlock operation can be performed properly.
  
  OK: Go to next step
  
  NG: Go to Step 9.

Check the transmitter battery.

Check the transmitter battery level of the first electrical key transmitter SUB-ASSY checked.

Hold down the lock switch on the transmitter for 5 seconds and check how many times the LED on the transmitter blinks.

RESULT DESCRIPTION

Result	Go to
The LED on the transmitter does not light up while the switch is held down.	A
The LED on the transmitter blinks 3 times while the switch is held down.	B
The LED on the transmitter blinks twice but not for the third time.	C

NOTE:

While in use, the electrical key transmitter SUB-ASSY transmits voltage information to the collation ECM (smart key ECM ASSY). If the voltage is 2.4 V or less, the collation ECM (smart key ECM ASSY) displays [Yes] for [Key Low Battery] (an item under [Data monitor]). (Refer to DATA MONITOR/ACTIVE TEST )
To start the engine when the transmitter battery is drained, depress the brake pedal, hold down the engine switch, and place the electrical key transmitter SUB-ASSY over the engine switch.

Go to next step
Replacement of the electrical key transmitter SUB-ASSY
Replace the transmitter battery.

Inspect the transmitter battery unit (voltage).

Remove the transmitter battery from the faulty electrical key transmitter SUB-ASSY. (Refer to TRANSMITTER BATTERY (WITH SMART ENTRY) )
Using tape or the like, attach the lead wire (0.60 mm or less in diameter, including the wire sheath) to the negative terminal.
CAUTION: Do not twist the lead wire around the terminal, tuck it into the terminal, or solder it to the terminal. If the terminal is deformed or damaged, the transmitter battery cannot be properly installed.

Carefully pull the lead wire, and insert the previously removed transmitter battery.

Courtesy of SUBARU OF AMERICA, INC.

Measure the voltage of the transmitter battery.

NOTE:

Measure the transmitter battery voltage by bringing the electrical key transmitter SUB-ASSY inside the lock entry operating range while operating the lock sensor on the door handle.
Perform this measurement when the key is at the room temperature.
During signal transmission, the key transmits voltage information to the collation ECM (smart key ECM ASSY). If the voltage is 2.4 V or less, [Yes] is displayed for [Key Low Battery] (an item under [Data monitor]). (Refer to DATA MONITOR/ACTIVE TEST )

Voltage

INSPECTION TERMINALS AND SPECIFIED CONDITION

Inspection terminals	Switch conditions	Specified condition
Transmitter battery positive terminal (+) - transmitter battery negative terminal (-)	Change the power mode to IG OFF, close all doors, and touch the lock sensor.	2.5 - 3.2V

OK: Go to next step

NG: Replace the transmitter battery.

Replacement of the electrical key transmitter SUB-ASSY

Checking the waveform environment
1. Move the electrical key transmitter SUB-ASSY towards the door control receiver and check that the wireless and entry functions work properly.
  NOTE:
  - Try moving the electrical key transmitter SUB-ASSY closer to the door control receiver, so that it is less likely to be affected by interference from external radio waves. In this way, you can identify if the problem is caused by external radio waves or not.
  - If this inspection reveals that the problem occurs in certain locations or during certain periods of time, the problem is likely due to interference from external radio waves. In addition, installing an additional component to the vehicle makes the vehicle more susceptible to interference from external radio waves. If such components are found, remove them, and then proceed to check the operation.
  - Being close to a broadcast antenna, a large video display, a wireless garage door opener system, a wireless security camera, or a home security system makes the vehicle susceptible to interference from external radio waves. If this is the case, move the vehicle to another location to check if the problem improves.
  - If a tool for checking radio waves such as a signal-strength meter is available, take measurements in the LF band (which is used by the vehicle antenna to create a detection area) and the RF band (which is used by the electrical key transmitter SUB-ASSY for signal transmission) in the vicinity of the vehicle to check where the radio waves might be present.
  Criteria: Both the wireless and entry functions work properly.
  
  OK: Go to next step
  
  NG: Go to Step 10.
  
  Interference from external radio waves

Read numerical values using the SSM4 [ACC SW], [Ignition].

Connect the SSM4 to the DLC3.
Turn the ignition switch to ON.
Turn on the SSM4.
Enter the following menus: [Body Control] →[Active Test]

Based on the SSM4 display contents, read the [Active Test].

RANGE DESCRIPTION - MAIN BODY

Tester display	Measurement items/range	Normal condition	Notes for diagnosis
[ACC SW]	The engine switch is ON (ACC)/OFF or ON.	OFF: The engine switch is OFF. ON: The engine switch is on (ACC).	-
[Ignition]	The engine switch is ON (IG)/[OFF] or [ON]	OFF: The engine switch is OFF. ON: Engine switch is ON (IG)	-

OK: Go to next step

NG: Refer to the troubleshooting procedure for the main body ECM (refer to HOW TO PROCEED WITH TROUBLESHOOTING ).

Check the harnesses and connectors (collation ECM (smart key ECM ASSY) - battery and chassis ground).

Disconnect the D48 collation ECM (smart key ECM ASSY) connector.

Measure the resistance according to the following table.

Resistance

Inspection terminals	Inspection conditions	Standard value
D48-11 (GND) - Chassis ground	Always	1 Ωor less

Measure the voltage according to the following table. Voltage

Inspection terminals	Inspection conditions	Standard value
D48-2 (+B) - chassis ground	Always	11 - 14 V

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Reconnect the D48 connector of the collation ECM (smart key ECM ASSY).
OK: Go to next step

NG: Repair or replace the harnesses or connectors.

Check the harnesses and connectors (collation ECM - door control receiver).

Disconnect the D40 collation ECM (smart key ECM ASSY) connector.
Disconnect the H28*1 or H26*2 door control receiver connector.

Measure the resistance according to the following table.

*1: With TPMS

*2: Without TPMS

Resistance

Inspection terminals

Inspection conditions

Standard value

D40-5 (RCO) - H28-10 (RCO)⁽¹⁾
D40-5 (RCO) - H26-4 (+5)⁽²⁾

Always

1 Ωor less

D40-17 (RDA) - H28-9
(DATA)⁽¹⁾ D40-17 (RDA) - H26-5 (DATA)⁽²⁾

Always

1 Ωor less

D40-19 (RSSI) - H28-6 (RSSI)⁽¹⁾
D40-19 (RSSI) - H26-2 (RSSI)⁽²⁾

Always

1 Ωor less

D40-5 (RCO) - chassis ground

Always

10 kΩ or more

D40-17 (RDA) - chassis ground

Always

10 kΩ or more

D40-19 (RSSI) - chassis ground

Always

10 kΩ or more

⁽¹⁾

With TPMS

⁽²⁾	Without TPMS

OK: Go to next step

NG: Repair or replace the harnesses or connectors.

Inspect the door control receiver unit.

Reconnect the H28*1 or H26*2 door control receiver connector.

Measure the resistance according to the following table.

Resistance

Inspection terminals

Inspection conditions

Standard value

H28-12 (GND) - chassis ground⁽¹⁾
H26-1 (GND) - chassis ground⁽²⁾

Always

1 Ωor less

⁽¹⁾

With TPMS

⁽²⁾	Without TPMS

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Reconnect the D48 connector of the collation ECM (smart key ECM ASSY).
OK: Go to next step

NG: Replace the door control receiver.

Unit inspection of the collation ECM (smart key ECM ASSY)

Reconnect the D40 collation ECM (smart key ECM ASSY) connector.

Measure the voltage according to the following table.

Resistance

Inspection terminals	Inspection conditions	Standard value
D48-11 (GND) - Chassis ground	Always	1 Ωor less

Measure the voltage according to the following table. Voltage

Inspection terminals

Inspection conditions

Standard value

H28-10 (RCO) - H28-12 (GND)⁽¹⁾
H26-4 (+5) - H26-1 (GND)⁽²⁾

Procedure:

The engine switch is OFF.
The electrical key transmitter SUB-ASSY is not pressed.

1 V or less

Procedure:

The engine switch is OFF.
The electrical key transmitter SUB-ASSY is pressed.

4.5 - 5.5V

⁽¹⁾

With TPMS

⁽²⁾	Without TPMS

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OK: Go to next step

NG: Replacement of the collation ECM (smart key computer ASSY)

Inspect the door control receiver unit.

Measure the voltage according to the following table. Voltage

Inspection terminals

Inspection conditions

Standard value

H28-6 (RSSI) - H28-12 (GND)⁽¹⁾
H26-2 (RSSI) - H26-1 (GND)⁽²⁾

Procedure:

All doors are closed.
All doors are locked.
The electrical key transmitter SUB-ASSY is not pressed.

11 - 14 V

Procedure:

All doors are closed.
All doors are locked.
The electrical key transmitter SUB-ASSY is pressed.

2V or less

H28-9 (DATA) - H28-12 (GND)⁽¹⁾
H26-5 (DATA) - H26-1 (GND)⁽²⁾

Procedure:

All doors are closed.
All doors are locked.
The electrical key transmitter SUB-ASSY is not pressed.

11 - 14 V

Procedure:

All doors are closed.
All doors are locked.
The electrical key transmitter SUB-ASSY is pressed.

11 to 14 V →2 V or less →11 to 14 V, pulses generated at normal time intervals

⁽¹⁾

With TPMS

⁽²⁾	Without TPMS

Courtesy of SUBARU OF AMERICA, INC.

OK: Go to next step

NG: Replace the door control receiver.

Replacement of the collation ECM (smart key computer ASSY)
1. Temporarily replace the collation ECM (smart key ECM ASSY) with a new one.
  CAUTION: When replacing the collation ECM (smart key ECM ASSY), it is also necessary to replace all the electrical key transmitter SUB-ASSYs.
Check the wireless door lock control system.
1. Check that the wireless door lock function operates properly. (Refer to OPERATION CHECK )
  Criteria: The wireless door lock function operates properly.
  
  OK: Go to next step
  
  NG: Replace the main body ECM (multiplex network body ECM).
  
  END (collation ECM (smart key ECM ASSY) detected)