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.
HINT:
If "+B of GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1297, repair the "+B or GND short malfunction of communication bus" DTCs first (See DTC B1266 SHORT TO B+ IN INSTRUMENT PANEL SYSTEM COMMUNICATION BUS MALFUNCTION; DTC B1267 SHORT TO GND IN INSTRUMENT PANEL SYSTEM COMMUNICATION BUS MALFUNCTION ).
- INSPECT FUSE (LH-IG)
- Remove the LH-IG fuse from the main body ECU LH (cowl side junction block LH).
- Measure the resistance according to the value(s) in the table below
Standard Resistance
RESISTANCE REFERENCETaster Connection Condition Specified Condition LH-IG fuse Always Below 1 Ω
NG: REPLACE FUSE (LH-IG)
OK: Go to Next Step
- CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU - BATTERY AND BODY GROUND)
- Disconnect the Q37 connector
- Measure the voltage and resistance according to the value(s) in the table below.
Standard Voltage
VOLTAGE SPECIFICATIONTester Connection Switch Condition Specified Condition Q37-8 (IG) - Body ground Engine switch on (IG) 11 to 14 V Standard Resistance
RESISTANCE REFERENCETester Connection Condition Specified Condition Q37-27 (E) - Body ground Always Below 1 Ω
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (CLEARANCE WARNING ECU - BATTERY AND BODY GROUND)
OK: Go to Next Step
- CHECK HARNESS AND CONNECTOR (COMMUNICATION LINE)
- Disconnect the Q37, A27 and J34 connectors
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
RESISTANCE REFERENCETester Connection Condition Specified Condition Q37-26(M+) - A27-6 (MPX2) or J34-6 (MPX+) Always Below 1 Ω
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE CLEARANCE WARNING ECU (See REMOVAL )