Toyota 2GR-FE Manual page 530

ES–374
MONITOR DESCRIPTION
The Air-Fuel Ratio (A/F) sensor varies its output voltage in proportion to the air-fuel ratio. If the A/F sensor
impedance (alternating current resistance) or output voltage deviates greatly from the standard range, the
ECM determines that there is an open or short malfunction in the A/F sensor circuit.
MONITOR STRATEGY
Related DTCs
ES
Required Sensors/Components (Main)
Required Sensors/Components (Sub)
Frequency of Operation
Duration
MIL Operation
Sequence of Operation
TYPICAL ENABLING CONDITIONS
Monitor runs whenever following DTCs are not present
P2238 and P2241 (open circuit between AF+ and AF-):
AF+ terminal voltage
AF- terminal voltage
Difference between AF+ and AF- terminal voltages
ECT
Engine condition
Fuel-cut
Time after engine start
A/F sensor heater duty-cycle
Time after A/F sensor heating
Battery voltage
Ignition switch
Others:
Battery voltage
Ignition switch
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
P2238: A/F sensor (Bank 1) open circuit between AF+ and AF-
P2238: A/F sensor (Bank 1) short circuit between AF+ and AF-
P2238: A/F sensor (Bank 1) short circuit between AF+ and GND
P2239: A/F sensor (Bank 1) short circuit between AF+ and +B
P2241: A/F sensor (Bank 2) open circuit between AF+ and AF-
P2241: A/F sensor (Bank 2) short circuit between AF+ and AF-
P2241: A/F sensor (Bank 2) short circuit between AF+ and GND
P2242: A/F sensor (Bank 2) short circuit between AF+ and +B
P2252: A/F sensor (Bank 1) short circuit between AF- and GND
P2253: A/F sensor (Bank 1) short circuit between AF- and +B
P2255: A/F sensor (Bank 2) short circuit between AF- and GND
P2256: A/F sensor (Bank 2) short circuit between AF- and +B
A/F sensor
Engine Coolant Temperature (ECT) sensor, Crankshaft position sensor
Once per driving cycle
10 seconds
2 driving cycles
None
P0031, P0032, P0051, P0052 (A/F sensor heater - Sensor 1)
P0100 - P0103 (MAF meter)
P0110 - P0113 (IAT sensor)
P0115 - P0118 (ECT sensor)
P0120 - P0223, P2135 (TP sensor)
P0125 (Insufficient ECT for Closed Loop)
P0171, P0172 (Fuel system)
P0300 - P0308 (Misfire)
P0335 (CKP sensor)
P0500 (VSS)
0.5 to 4.5 V
0.5 to 4.5 V
0.1 to 0.8 V
5°C (41°F) or more (Varies with ECT at engine start)
Running
OFF
10 seconds or more
ON
5 seconds or more
11 V or more
ON
10.5 V or more
ON