Check CAN Communication Circuit

WARNING: This page is about a different car, the 2014 Subaru BRZ. However, it is still accessible from the selected car via links, so may be relevant.

Inspection steps

CAUTION:

Before measuring the resistance of CAN bus, turn the ignition OFF and leave the vehicle as is for at least one minute without operating keys, switches, and doors. Disconnect the battery and wait for another one minute or more.
When a connector is not fully connected, it may case CAN communication failure. To avoid such failure, make sure to perform contact pressure test.

Bring in the car

Use the tester to measure the resistance between terminals.

RESISTANCE

Inspection terminals	Inspection conditions	Standard value
D10-6 - chassis ground	Always	10 Ωor more
D10-14 - chassis ground	Always	10 Ωor more

NG: Check for ground short. (Refer to CHECK FOR SHORT TO GROUND )

Fig 1: Identifying Data Link Connector Terminals

Courtesy of SUBARU OF AMERICA, INC.

OK: Go to Next Step

Check from data link connector

Use the tester to measure the voltage between terminals.

VOLTAGE

Inspection terminals	Inspection conditions	Standard value
D10-6 - chassis ground	Always	Less than 5 V
D10-14 - chassis ground	Always	Less than 5 V

NG: Check for short circuit in the battery (Refer to CHECK FOR SHORT TO BATTERY )

Fig 2: Identifying Data Link Connector Terminals

Courtesy of SUBARU OF AMERICA, INC.

OK: Go to Next Step

Check from data link connector

Use the tester to measure the resistance between terminals.

RESISTANCE

Inspection terminals	Inspection conditions	Standard value
D10-6 - D10-14	Always	57 to 63 Ω

Fig 3: Identifying Data Link Connector Terminals

Courtesy of SUBARU OF AMERICA, INC.

CRITERIA

Result	Go to
OK (57 to 63 Ω)	A
NG (63 Ωor more)	B
NG (less than 57 Ω)	C

A: A sub-line may be open. Perform the inspection for the resistance between 57 Ωand 63 Ωrelevant to the detected DTC.

B: Perform the inspection for the resistance of 63 Ωor more. (Refer to 63 ΩOR MORE )

C: Perform the inspection for the resistance of Less than 57 Ω. (Refer to LESS THAN 57 Ω )

List

Item	Contents	Note
Check for short to ground	Refer to "CHECK FOR SHORT TO GROUND	Shorted to ground in the communication circuit or control module.
Check for short to battery	Refer to "CHECK FOR SHORT TO BATTERY "	Shorted to battery power supply system in the communication circuit or control module.
Less than 57 Ω	Refer to the inspection for the resistance of less than 57 Ω. (Refer to LESS THAN 57 Ω )	CAN-H and CAN-L may be shorted on CAN communication circuit, where the resistance is lower than combined resistance of the terminal resistor.
63 Ωor more	Refer to the inspection for the resistance of 64 Ωor more. (Refer to 63 ΩOR MORE )	CAN communication circuit may be open on CAN communication circuit, where the resistance is higher than combined resistance of the terminal resistor.
Sub-lines 57-63 Ω(Engine control computer system)	Refer to the inspection for the sub-lines 57-64 Ω(Engine control computer system). (Refer to SUB-LINES 57-63 Ω(ENGINE CONTROL COMPUTER SYSTEM) )	The inspection is applied in case of missing or invalid data for the engine control computer.
Sub-lines 57-63 Ω(Brake actuator assembly system)	Refer to the inspection for the sub-lines 57-64 Ω(Brake actuator assembly system). (Refer to SUB-LINES 57-63 Ω(BRAKE ACTUATOR SYSTEM) )	The inspection is applied in case of missing or invalid data for the brake actuator assembly.
Sub-lines 57-63 Ω(Transmission control computer assembly system)	Refer to the inspection for the sub-lines 57-64 Ω(Transmission control computer assembly system). (Refer to SUB-LINES 57-63 Ω(TRANSMISSION CONTROL COMPUTER ASSEMBLY SYSTEM) )	The inspection is applied in case of missing or invalid data for the transmission control computer assembly.
Sub-lines 57-63 Ω(Body integrated unit system)	Refer to the inspection for the sub-lines 57-65 Ω(Body integrated unit system). (Refer to SUB-LINES 57-63 Ω(BODY INTEGRATED UNIT SYSTEM) )	The inspection is applied in case of missing or invalid data for the body integrated unit.
Sub-lines 57-63 Ω(Spiral cable sub-assembly system)	Refer to the inspection for the sub-lines 57-64 Ω(Spiral cable sub-assembly system). (Refer to SUB-LINES 57-63 Ω(SPIRAL CABLE SUB-ASSEMBLY SYSTEM) )	The inspection is applied in case of missing or invalid data for the spiral cable sub-assembly.
Sub-lines 57-63 Ω(Air conditioner amplifier assembly system)	Refer to the inspection for the sub-lines 57-64 Ω(A/C control panel system). (Refer to SUB-LINES 57-63 Ω(AIR CONDITIONER CONTROL PANEL SYSTEM) )	The inspection is applied in case of missing or invalid data for A/C.
Sub-lines 57-63 Ω(Electric power steering computer assembly system)	Refer to the inspection for the sub-lines 57-64 Ω(Electric power steering computer assembly system). (Refer to SUB-LINES 57-63 Ω(ELECTRIC POWER STEERING SYSTEM) )	The inspection is applied in case of missing or invalid data for the electric power steering.
Sub-lines 57-63 Ω(Combination meter assembly system)	Refer to the inspection for the sub-lines 57-64 Ω(Combination meter assembly system). (Refer to SUB-LINES 57-63 Ω(COMBINATION METER assembly SYSTEM) )	The inspection is applied in case of missing or invalid data for the meter.
Sub-lines 57-63 Ω(Airbag system)	Refer to the inspection for the sub-lines 57-64 Ω(A/B CM system). (Refer to SUB-LINES 57-63 Ω(AIRBAG SYSTEM) )	The inspection is applied in case of missing or invalid data for the airbag.
Sub-lines 57-63 Ω(Keyless access system)	Refer to the inspection for the sub-lines 57-64 Ω(Keyless access system). (Refer to SUB-LINES 57-63 Ω(KEYLESS ACCESS SYSTEM) )	The inspection is applied in case of missing or invalid data for the collation ECM (Smart key computer assembly).