Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Turn the engine switch off before measuring the resistance of CAN bus main wires and CAN bus branch wires.
After the engine switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the engine switch, any other switches, or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

HINT

Operating the engine switch, any switches, or any doors triggers related ECU and sensor communication with the CAN This communication will cause the resistance value to change

CHECK OPEN IN CAN BUS WIRE (SKID CONTROL ECU BRANCH LINE)

Turn the engine switch off.
Disconnect the skid control ECU connector (J77)

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

Standard Resistance

RESISTANCE REFERENCE

Tester Connection	Condition	Specified Value
J77-8(CANH) - J77-16 (CANL)	Engine switch off	54 to 69 Ω

Fig 1: Identifying J77 Connector Terminal

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NG: REPAIR OR REPLACE SKID CONTROL ECU BRANCH WIRE OR CONNECTOR (CAN-H, CAN-L)

OK: Go to Next Step

CHECK WIRE HARNESS (IG1, GND1)

Disconnect the skid control ECU connectors (J78) and (A35).

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

Standard Resistance

RESISTANCE REFERENCE

Tester Connection	Condition	Specified Value
J78-26(GND1) - Body ground	Always	Below 1 Ω

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

Standard Voltage

VOLTAGE SPECIFICATION

Tester Connection	Condition	Specified Value
J77-1 (IG1) - Body ground	Engine switch on (IG)	10 to 14 V

Fig 2: Identifying Skid Control ECU Connectors J78 And A35

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE SKID CONTROL ECU ASSEMBLY (See REMOVAL )