Toyota 2GR-FE, Manual

Page: 358 / 1021

ES–202
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
NOTICE:
The Air-Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen
(HO2) sensor has a maximum output delay of approximately 20 seconds.
– Following the A/F CONTROL procedure enables technicians to check and graph the voltage outputs
of both the A/F and HO2 sensors.
– To display the graph, select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD
II / ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1S1 and O2S B1S2 or AFS B2S1 and
O2S B2S2. Press the YES button and then the ENTER button. Then press the F4 button.
HINT:
•
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving
condition information as freeze frame data the moment a DTC is stored. When troubleshooting,
freeze frame data can be helpful in determining whether the vehicle was running or stopped,
whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as
other data recorded at the time of a malfunction.
• A low A/F sensor voltage could be caused by a rich air-fuel mixture. Check for conditions that
would cause the engine to run rich.
• A high A/F sensor voltage could be caused by a lean air-fuel mixture. Check for conditions that
would cause the engine to run lean.
O2S B1S2 or O2S B2S2 (HO2) +25% Rich More than 0.55
O2S B1S2 or O2S B2S2 (HO2) -12.5% Lean Less than 0.4
Case
A/F Sensor (Sensor 1)
Output Voltage
HO2 Sensor (Sensor 2)
Output Voltage
Main Suspected
Trouble Area
1
Injection Volume
+25%
-12.5%
Injection Volume
+25%
-12.5%
-
Output Voltage
More than 3.35 V
Less than 3.0 V
Output Voltage
More than 0.55 V
Less than 0.4 V
2
Injection Volume
+25%
-12.5%
Injection Volume
+25%
-12.5%
• A/F sensor
• A/F sensor heater
• A/F sensor circuit
Output Voltage
Almost
no reaction
Output Voltage
More than 0.55 V
Less than 0.4 V
3
Injection Volume
+25%
-12.5%
Injection Volume
+25%
-12.5%
• HO2 sensor
• HO2 sensor heater
• HO2 sensor circuit
Output Voltage
More than 3.35 V
Less than 3.0 V
Output Voltage
Almost
no reaction
4
Injection volume
+25%
-12.5%
Injection Volume
+25%
-12.5%
• Injector
• Fuel pressure
• Gas leakage from
exhaust system
(Air-fuel ratio
extremely lean or
rich)
Output Voltage
Almost
no reaction
Output Voltage
Almost
no reaction
Tester Display (Sensor) Injection Volumes Status Voltages