Toyota 2GR-FE Manual page 360

ES–204
Standard voltage
Tester Display (Sensor)
AFS B1S1 or AFS B2S1 (A/F)
AFS B1S1 or AFS B2S1 (A/F)
O2S B1S2 or O2S B2S2 (HO2)
ES
O2S B1S2 or O2S B2S2 (HO2)
Result
Status AFS
B1S1 or AFS
B2S1
Lean/Rich
Lean
Rich
Lean
Rich
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Injection Volumes
+25%
-12.5%
+25%
-12.5%
Status O2S
A/F Condition and A/F
B1S2 or O2S
Sensor Condition
B2S2
Lean/Rich Normal
Lean Actual air-fuel ratio lean
Rich Actual air-fuel ratio rich
Lean/Rich A/F sensor malfunction
Lean/Rich A/F sensor malfunction
(f) Monitor the voltage outputs of the A/F and HO2 sensors
(AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S
B2S2) displayed on the tester.
HINT:
• The A/F CONTROL operation lowers the fuel injection
volume by 12.5% or increases the injection volume by
25%.
• Each sensor reacts in accordance with increases and
decreases in the fuel injection volume.
Status
Rich
Lean
Rich
Lean
Misfires
-
May occur
-
-
-
Lean: During A/F CONTROL, the A/F sensor output
voltage (AFS) is consistently more than 3.35 V, and the
HO2 sensor output voltage (O2S) is consistently less
than 0.4 V.
Rich: During A/F CONTROL, the AFS is consistently less
than 3.0 V, and the O2S is consistently more than 0.55 V.
Lean/Rich: During A/F CONTROL of the ACTIVE TEST,
the output voltage of the heated oxygen sensor
alternates correctly.
B Go to step 11
C
Go to step 15
Voltages
Less than 3.0
More than 3.35
More than 0.55
Less than 0.4
Suspected Trouble Areas
-
• PCV valve and hose
• PCV hose connections
• Injector blockage
• Gas leakage from
exhaust system
• Air induction system
• Fuel pressure
• Mass Air Flow (MAF)
meter
• Engine Coolant
Temperature (ECT)
sensor
• Injector leakage or
blockage
• Gas leakage from
exhaust system
• Ignition system
• Fuel pressure
• MAF meter
• ECT sensor
A/F sensor
A/F sensor
Proceed to
C
A
A
B
B