Dtc P0031 Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1)
Engine. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
CHECK TERMINAL VOLTAGE (POWER SOURCE)
CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
CHECK WHETHER DTC OUTPUT RECURS (DTC P0031, P0031 OR P101D)
CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - INTEGRATION RELAY (EFI MAIN))
DTC P0031 Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1) |
DTC P0032 Oxygen (A/F) Sensor Heater Control Circuit High (Bank 1 Sensor 1) |
DTC P101D A/F Sensor Heater Circuit Performance Bank 1 Sensor 1 Stuck ON |
DESCRIPTION
Refer to DTC P2195 (RAV4_ACA30 RM000000WC4093X.html).- HINT:
- Although the DTC titles refer to the oxygen sensor, these DTCs relate to the air fuel ratio sensor.
- Sensor 1 refers to the sensor mounted in front of the three way catalytic converter and located near the engine assembly.
- When either of these DTCs is stored, 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 signal to the control circuit to adjust the current through the heater. The air fuel ratio sensor heater circuit uses a relay on the +B side of the circuit.
DTC No.
| DTC Detection Condition
| Trouble Area
|
P0031
| The air fuel ratio sensor heater current is below 0.8 A (1 trip detection logic).
| - Open in air fuel ratio sensor heater circuit
- Air fuel ratio sensor heater (sensor 1)
- Integration relay (EFI MAIN relay)
- ECM
|
P0032
| The air fuel ratio sensor heater current is higher than 10 A (1 trip detection logic).
| - Short in air fuel ratio sensor heater circuit
- Air fuel ratio sensor heater (sensor 1)
- Integration relay (EFI MAIN relay)
- ECM
|
P101D
| The heater current is higher than the specified value while the heater is not operating (1 trip detection logic).
| ECM
|
WIRING DIAGRAM
Refer to DTC P2195 (RAV4_ACA30 RM000000WC4093X.html).
INSPECTION PROCEDURE
- NOTICE:
- Inspect the fuses for circuits related to this system before performing the following inspection procedure.
- 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 help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
| 1.INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) |
Disconnect the air fuel ratio sensor connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Condition
| Specified Condition
|
1 (HA1A) - 2 (+B)
| 20°C (68°F)
| 1.8 to 3.4 Ω
|
1 (HA1A) - 4 (A1A-)
| 20°C (68°F)
| 10 kΩ or higher
|
Text in Illustration*1
| Component without harness connected
(Air Fuel Ratio Sensor)
|
Reconnect the air fuel ratio sensor connector.
| 2.CHECK TERMINAL VOLTAGE (POWER SOURCE) |
Disconnect the air fuel ratio sensor connector.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection
| Switch Condition
| Specified Condition
|
B113-2 (+B) - Body ground
| Ignition switch ON
| 11 to 14 V
|
Text in Illustration*1
| Front view of wire harness connector
(to Air Fuel Ratio Sensor)
|
Reconnect the air fuel ratio sensor connector.
| 3.CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM) |
Disconnect the air fuel ratio sensor connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
Tester Connection
| Condition
| Specified Condition
|
B113-1 (HA1A) - B32-104 (HA1A)
| Always
| Below 1 Ω
|
- Standard Resistance (Check for Short):
Tester Connection
| Condition
| Specified Condition
|
B113-1 (HA1A) or B32-104 (HA1A) - Body ground
| Always
| 10 kΩ or higher
|
Text in Illustration*1
| Front view of wire harness connector
(to Air Fuel Ratio Sensor)
|
*2
| Front view of wire harness connector
(to ECM)
|
Reconnect the air fuel ratio sensor connector.
Reconnect the ECM connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR - ECM) |
|
|
| 4.CHECK WHETHER DTC OUTPUT RECURS (DTC P0031, P0031 OR P101D) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Clear the DTCs (RAV4_ACA30 RM000000PDK0BLX.html).
Start the engine.
Allow the engine to idle for 1 minute or more.
Enter the following menus: Powertrain / Engine and ECT / DTC.
Read the DTCs.
ResultResult
| Proceed to
|
DTC is not output
| A
|
DTC P0031, P0032 or P101D is output
| B
|
| 5.CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - INTEGRATION RELAY (EFI MAIN)) |
Disconnect the air fuel ratio sensor connector.
Remove the integration relay (EFI MAIN relay) from the engine room No. 1 relay block.
Disconnect the integration relay connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
Tester Connection
| Condition
| Specified Condition
|
B113-2 (+B) - 1A-4
| Always
| Below 1 Ω
|
- Standard Resistance (Check for Short):
Tester Connection
| Condition
| Specified Condition
|
B113-2 (+B) or 1A-4 - Body ground
| Always
| 10 kΩ or higher
|
Text in Illustration*1
| Front view of wire harness connector
(to Air Fuel Ratio Sensor)
|
*2
| Front view of wire harness connector
(to Integration Relay)
|
*3
| Engine Room No. 1 Relay Block
|
Reconnect the air fuel ratio sensor connector.
Reconnect the integration relay connector.
Reinstall the integration relay.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR - INTEGRATION RELAY (EFI MAIN)) |
|
|
