Inspection steps

NOTE: Read the freeze frame data using the SSM3. A part of the engine running conditions under which the engine trouble occurred is recorded in the freeze frame data, which is useful for troubleshooting.

Reading the SSM3 data ([Coolant Temp.])

Connect the SSM3 to the DLC3.
Turn the ignition switch to ON.
Select the following menu items using the SSM3: [BRZ Check] / [Each System Check] / [Engine Control System] / [Current Data Display & Save] / [Coolant Temp.]

Read [Coolant Temp.] displayed on the SSM3 with engine stopped.

RESULT

Result	Go to
-40°C {-40°F} (open circuit)	A
120°C {248°F} (short circuit)	B
Equal to actual coolant temperature	C

NOTE:

If the SSM3 display is -40°C {-40°F}, there is an open circuit.
If the SSM3 display is 120°C {248°F}, there is a short circuit.

B: Go to Step 4.

C: Inspection for problems that do not normally occur (Refer to CHECK PROBLEMS THAT DO NOT CONSTANTLY OCCUR )

A: Go to Next Step

Reading SSM3 data (wiring harness open circuit check)
SST 09843-18040

NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .
1. Connect the SSM3 to the DLC3.
2. Disconnect the E.F.I. water temperature sensor connectors.
3. Using SST (diagnostic check wire No. 2), short-circuit between terminals 2 and 1 of the E.F.I. water temperature sensor.
4. Turn the ignition switch to ON.
5. Select the following menu items using the SSM3: [BRZ Check] / [Each System Check] / [Engine Control System] / [Current Data Display & Save] / [Coolant Temp.]
6. Read the [Coolant Temp.] displayed on the SSM3.
  Displayed temperature: 120°C {248°F}
  
  Fig 1: Identifying EFI Water Temperature Sensor Connector Terminals
  Courtesy of SUBARU OF AMERICA, INC.
  
  NG: Go to Step 3.
  
  OK: Replacement of E.F.I. water temperature sensor (Refer to ENGINE COOLANT TEMPERATURE SENSOR (FA20) )

Check wiring harness and connector (engine control computer - E.F.I. water temperature sensor)

NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .

Disconnect the E.F.I. water temperature sensor connectors.
Disconnect the connector for the engine control computer.

Measure the resistance between the terminals. (Refer to ECM TERMINAL ARRANGEMENT for the terminal arrangement)

RESISTANCE (OPEN CIRCUIT CHECK)

Inspection terminals	Inspection conditions	Standard value
A36-30 (THW) - C35-2 (THW)	Always	Less than 1 Ω
A36-29 (E1) - C35-1 (E2)	Always	Less than 1 Ω

NG: Repair or replacement of wiring harness or connector

OK: Replacement of the engine control computer (Refer to REMOVAL )

Reading SSM3 data (wiring harness short circuit check)
1. Connect the SSM3 to the DLC3.
2. Disconnect the E.F.I. water temperature sensor connectors.
3. Turn the ignition switch to ON.
4. Select the following menu items using the SSM3: [BRZ Check] / [Each System Check] / [Engine Control System] / [Current Data Display & Save] / [Coolant Temp.]
5. Read the [Coolant Temp.] displayed on the SSM3. ES
  Displayed temperature: -40°C {-40°F}
  
  Fig 2: EFI Water Temperature Sensor And Engine Control Computer - Circuit Diagram
  Courtesy of SUBARU OF AMERICA, INC.
  
  NG: Go to Step 5.
  
  OK: Replacement of E.F.I. water temperature sensor (Refer to ENGINE COOLANT TEMPERATURE SENSOR (FA20) )

Check wiring harness and connector (E.F.I. water temperature sensor - engine control computer)

NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .

Disconnect the E.F.I. water temperature sensor connectors.
Disconnect the connector for the engine control computer.

Measure the resistance between the terminals. (Refer to ECM TERMINAL ARRANGEMENT for the terminal arrangement)

RESISTANCE (SHORT CIRCUIT CHECK)

Inspection terminals	Inspection conditions	Standard value
A36-30 (THW) and C35-2 (THW) - other terminals and chassis ground	Always	10 k Ωor more
A36-29 (E1) and C35-1 (E2) - other terminals and chassis ground	Always	10 k Ωor more

NG: Repair or replacement of wiring harness or connector

OK: Replacement of the engine control computer (Refer to REMOVAL )