Toyota 2GR-FE Manual page 417

Tester Display
(Sensor)
AFS B1 S1 or AFS B2 S1
(A/F)
AFS B1 S1 or AFS B2 S1
(A/F)
O2S B1 S2 or O2S B2 S2
(HO2)
O2S B1 S2 or O2S B2 S2
(HO2)
Result
Status Status
AFS B1 S1 O2S B1 S2
or or
AFS B2 S1 O2S B2 S2
Lean/Rich Lean/Rich
Lean Lean/Rich
Rich Lean/Rich
Lean/Rich Lean
Lean/Rich Rich
Lean Lean
Rich Rich
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
• Each sensor reacts in accordance with increases and
Injection Volume
+25 %
-12.5 %
+25 %
-12.5 %
A/F Condition
and A/F and
HO2 Sensor
Conditions
Normal
A/F sensor
malfunction
A/F sensor
malfunction
HO2 sensor
malfunction
HO2 sensor
malfunction
Actual air-fuel
ratio lean
Actual air-fuel
ratio lean
Lean:
Rich:
Lean/Rich:
B
decreases in the fuel injection volume.
Status
Rich
Lean
Rich
Lean
Misfire Main Suspected Trouble Areas
• Three-Way Catalytic
Converter (TWC)
-
• Gas leakage from exhaust
system
- • A/F sensor
May occur • A/F sensor
• HO2 sensor
- • Gas leakage from exhaust
system
• HO2 sensor
- • Gas leakage from exhaust
system
• Extremely rich or lean
actual air-fuel ratio
May occur
• Gas leakage from exhaust
system
• Extremely rich or lean
actual air-fuel ratio
-
• Gas leakage from exhaust
system
During A/F CONTROL, the A/F sensor (AFS) output
voltage is consistently more than 3.35 V, and the HO2
sensor output voltage (O2S) is consistently less than
0.4 V.
During A/F CONTROL, the AFS is consistently less
than 3.0 V, and the O2S is consistently more than
0.55 V.
During A/F CONTROL of the ACTIVE TEST, the
output voltage of the HO2 sensor alternates correctly.
CHECK AND REPLACE AIR FUEL RATIO
SENSOR
ES–261
Voltage
Less than 3.0 V
More than 3.35 V
More than 0.55 V
Less than 0.4 V
ES
Proceed to
A
B
B
C
C
A
A