Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CONNECTORS
1. Check that the connectors are securely connected and the terminals are not deformed or loose.
  OK:
  
  The connectors are securely connected and the terminals are not deformed or loose.
NG: REPAIR OR REPLACE CONNECTORS

OK: Go to Next Step

CHECK WIRE HARNESS (POWER SOURCE CONTROL ECU - BODY GROUND)

Disconnect the J55 ECU connector.

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

Standard resistance

STANDARD RESISTANCE SPECIFICATION

Tester Connection (Symbols)	Condition	Specified Condition
J55-6 (GND2) - Body ground	Always	Below 1 Ω

Fig 1: Identifying J55 Power Source Control ECU Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

CHECK WIRE HARNESS (POWER SOURCE CONTROL ECU - ECM)

Disconnect the A5 ECM connector.

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

Standard resistance

STANDARD RESISTANCE SPECIFICATION

Tester Connection (Symbols)	Condition	Specified Condition
J55-31 (CTSW) - A5-11 (ACCR)	Always	Below 1 Ω
J55-31 (CTSW) or A5-11 (ACCR) - Body ground	Always	10 kΩ or higher

Fig 2: Identifying A5 ECM And J55 Power Source Control ECU Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

INSPECT ECM

Reconnect the A5 ECM connector.

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

Standard voltage

STANDARD VOLTAGE SPECIFICATION

Tester Connection (Symbols)	Condition	Specified Condition
J55-31 (CTSW) - Body ground	Always	8 to 14 V

Fig 3: Identifying Terminal CTSW Of J55 Power Source Control ECU Connector

NG: REPLACE ECM

OK: Go to Next Step

INSPECT POWER SOURCE CONTROL ECU

Reconnect the J55 ECU connector.

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

Standard voltage

STANDARD VOLTAGE SPECIFICATION

Terminal No. (Symbol)	Condition	Specified condition
J55-31 (CTSW) - Body ground	Brake pedal depressed (A/T) or Clutch pedal depressed (M/T), Engine switch on (ST)	0.1 to 0.8 V (*1)
HINT: *1: Voltage is output only when the engine is cranking.

Fig 4: Identifying Terminal CTSW Of J55 Power Source Control ECU Connector

NG: REPLACE POWER SOURCE CONTROL ECU

OK: CHECK INTERMITTENT PROBLEMS