Toyota 2GR-FE Manual page 525

Reference (System Diagram of Bank 1 Sensor 1):
A/F Relay
From
Battery
From
EFI
Relay
OK
14
CHECK AIR INDUCTION SYSTEM
OK
15
CHECK FUEL PRESSURE (HIGH PRESSURE SIDE AND LOW PRESSURE SIDE)
OK
16
REPLACE AIR FUEL RATIO SENSOR
NEXT
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
A/F
+B
A1A-
NG
(a) Check the air induction system for vacuum leakage.
OK:
No leakage from air induction system.
NG
(a) Check the fuel pressure.
NG
(a) Replace the air fuel ratio sensor (See page EC-19).
A/F Sensor
Heater
HA1A HA1A
Sensor
A1A+ A1A+
A1A-
REPAIR OR REPLACE HARNESS OR
CONNECTOR
REPAIR OR REPLACE AIR INDUCTION
SYSTEM
REPAIR OR REPLACE FUEL SYSTEM
ES–369
ECM
Duty
Control
ES
A133850E06