2AZ-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–81
ES
HINT:
• Although the DTC titles say oxygen sensor, these DTCs relate to the Air-Fuel Ratio (A/F) sensor.
• Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and
located near the engine assembly.
DESCRIPTION
Refer to DTC P2195 (see page ES-292).
HINT:
• When either of these DTCs is set, the ECM enters fail-safe mode. The ECM turns off the A/F sensor
heater in fail-safe mode. Fail-safe mode continues until the ignition switch is turned OFF.
• The ECM provides a pulse width modulated control circuit to adjust the current through the heater. The
A/F sensor heater circuit uses a relay on the B+ side of the circuit.
DTC P0031Oxygen (A/F) Sensor Heater Control Circuit
Low (Bank 1 Sensor 1)
DTC P0032Oxygen (A/F) Sensor Heater Control Circuit
High (Bank 1 Sensor 1)
DTC No. DTC Detection Conditions Trouble Areas
P0031Air-Fuel Ratio (A/F) sensor heater current less than 0.8 A
(1 trip detection logic)• Open in A/F sensor heater circuit
• A/F sensor heater (sensor 1)
• Integration relay (EFI MAIN relay)
•ECM
P0032Air-Fuel Ratio (A/F) sensor heater current more than 10 A
(1 trip detection logic)• Short in A/F sensor heater circuit
• A/F sensor heater (sensor 1)
• Integration relay (EFI MAIN relay)
•ECM
A127244E01
2AZ-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–87
ES
DESCRIPTION
Refer to DTC P0136 (see page ES-129).
HINT:
• When any of these DTCs are set, the ECM enters fail-safe mode. The ECM turns off the Heated
Oxygen (HO2) Sensor heater in fail-safe mode. Fail-safe mode continues until the ignition switch is
turned OFF.
• The ECM provides a pulse width modulated control circuit to adjust the current through the heater. The
HO2 sensor heater circuit uses a relay on the B+ side of the circuit.
DTC P0037Oxygen Sensor Heater Control Circuit Low
(Bank 1 Sensor 2)
DTC P0038Oxygen Sensor Heater Control Circuit High
(Bank 1 Sensor 2)
DTC P0141Oxygen Sensor Heater Circuit Malfunction
(Bank 1 Sensor 2)
DTC No. DTC Detection Conditions Trouble Areas
P0037Heated Oxygen (HO2) sensor heater current less than 0.3 A
(1 trip detection logic)• Open in HO2 sensor heater circuit
• HO2 sensor heater (sensor 2)
• Integration relay (EFI MAIN relay)
•ECM
P0038Heated Oxygen (HO2) sensor heater current more than 2 A
(1 trip detection logic)• Short in HO2 sensor heater circuit
• HO2 sensor heater (sensor 2)
• Integration relay (EFI MAIN relay)
•ECM
P0141Cumulative heater resistance correction value exceeds
threshold
(2 trip detection logic)• Open or short in HO2 sensor heater circuit
• HO2 sensor heater (sensor 2)
• Integration relay (EFI MAIN relay)
•ECM
A133556E01
