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 (B1214 and B1215) are detected at the same time as "communication stop" DTC B1280, repair the "+B or GND short malfunction of communication bus" DTCs first (See DTC B1214 SHORT TO B+ IN DOOR SYSTEM COMMUNICATION BUS MALFUNCTION; DTC B1215 SHORT TO GND IN DOOR SYSTEM COMMUNICATION BUS MALFUNCTION )
- INSPECT FUSE (MPX-B)
- Remove the MPX-B from the engine room relay block No 1
- Measure the resistance according to the value(s) in the table below
Standard Resistance
RESISTANCE REFERENCETester Connection Condition Specified Condition MPX-B fuse Always Below 1 Ω
NG: REPLACE FUSE (MPX-B)
OK: Go to Next Step
- CHECK HARNESS AND CONNECTOR (COWL SIDE JUNCTION BLOCK LH - BATTERY AND BODY GROUND)
- Disconnect the LD junction block connector
- Measure the voltage and resistance according to the value(s) in the table below
Standard Voltage
VOLTAGE SPECIFICATIONTester Connection Condition Specified Condition LD-18 (MPXB) - Body ground Always 11 to 14 V Standard Resistance
RESISTANCE REFERENCETester Connection Condition Specified Condition LD-3 (GND) - Body ground Always Below 1 Ω
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (COWL SIDE JUNCTION BLOCK LH - BATTERY AND BODY GROUND)
OK: Go to Next Step
- CHECK HARNESS AND CONNECTOR (COMMUNICATION LINE)
- Disconnect the Q3, A30, M7 and 2F connectors
- Measure the resistance according to the value(s) in the table below
Standard Resistance
RESISTANCE REFERENCETester Connection Condition Specified Condition Q3-15(MPX1) - M7-7 (MPX1) Always Below 1 Ω A30-17 (MPX2) - 2F-6 (MPX2) Always Below 1 Ω
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE MAIN BODY ECU LH (COWL SIDE JUNCTION BLOCK LH)