Toyota 2GR-FE Manual page 336

ES–180
ES
DTC No.
P0136
P0156
P0137
P0157
P0138
P0158
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Atmospheric Air
Cover
Exhaust Gas
DTC Detection Condition
• Abnormal voltage output:
During active air-fuel ratio control, following
conditions (a) and (b) are met for a certain
period of time (2 trip detection logic)
(a) Heated Oxygen (HO2) sensor voltage does
not decrease to less than 0.2 V
(b) HO2 sensor voltage does not increase to
more than 0.6 V
• Low impedance:
Sensor impedance is less than 5 Ω for more
than 30 seconds when ECM presumes sensor
to being warmed up and operating normally (2
trip detection logic)
• Low voltage (open):
During active air-fuel ratio control, following
conditions (a) and (b) are met for a certain
period of time (2 trip detection logic)
(a) HO2 sensor voltage output less than 0.21 V
(b) Target air-fuel ratio rich
• High impedance:
Sensor impedance is 15 kΩ or more for more
than 90 seconds when ECM presumes sensor
to being warmed up and operating normally (2
trip detection logic)
• High voltage (short):
During active air-fuel ratio control, following
conditions (a) and (b) are met for a certain
period of time (2 trip detection logic)
(a) HO2 sensor voltage output 0.59 V or more
(b) Target air-fuel ratio lean
• Extremely high voltage (short):
HO2 sensor voltage output exceeds 1.2 V for
more than 30 seconds (2 trip detection logic)
Housing
Output Voltage
Platinum Electrode
Solid Electrolyte
(Zirconia Element)
Heater
Coating (Ceramic)
Richer - Air Fuel Ratio - Leaner
• Open or short in HO2 sensor (bank 1, 2 sensor 2)
circuit
• HO2 sensor (bank 1, 2 sensor 2)
• HO2 sensor heater (bank 1, 2 sensor 2)
• Air-Fuel Ratio (A/F) sensor (bank 1, 2 sensor 1)
• Engine room junction block (EFI relay)
• Gas leakage from exhaust system
• Open in HO2 sensor (bank 1, 2 sensor 2) circuit
• HO2 sensor (bank 1, 2 sensor 2)
• HO2 sensor heater (bank 1, 2 sensor 2)
• Engine room junction block (EFI relay)
• Gas leakage from exhaust system
• Short in HO2 sensor (bank 1, 2 sensor 2) circuit
• HO2 sensor (bank 1, 2 sensor 2)
• ECM internal circuit malfunction
Ideal Air Fuel Mixture
Trouble Area
A115539E08