Nissan Sentra B18 (2020-2025) Service Manual: P0031 A/f Sensor 1 Heater
Dtc Description
DTC Description
DTC DETECTION LOGIC
|
DTC |
CONSULT screen terms (Trouble diagnosis content) |
DTC detection condition |
|
|
P0031 |
A/F SEN1 HTR (B1) (HO2S heater control circuit low bank 1 sensor 1) |
Diagnosis condition |
Engine running at idle |
|
Signal (terminal) |
A/F sensor 1 heater signal |
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|
Threshold |
An excessively low voltage signal is sent to ECM through the A/F sensor 1 heater |
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|
Diagnosis delay time |
— |
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POSSIBLE CAUSE
-
Harness or connectors (The A/F sensor 1 heater circuit is open or shorted.)
-
The A/F sensor 1 heater
FAIL-SAFE
Not applicable
Confirmation Procedure
Confirmation Procedure
-
PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
>>GO TO 2.
-
PERFORM DTC CONFIRMATION PROCEDURE
-
Start the engine and let it idle for at least 10 seconds.
-
Check 1st trip DTC.
Is 1st trip DTC detected?
YES >>Proceed to DTC Diagnosis Procedure.
NO-1 >>To check malfunction symptom before repair: Refer to Intermittent Incident.
NO-2 >>Confirmation after repair: INSPECTION END
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Dtc Diagnosis Procedure
DTC Diagnosis Procedure
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CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY
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Turn ignition switch OFF.
-
Disconnect air fuel ratio (A/F) sensor 1 harness connector.
-
Turn ignition switch ON.
-
Check the voltage between A/F sensor 1 harness connector and ground.
+
−
Voltage
A/F sensor 1
Connector
Terminal
F12
4
Ground
Battery voltage
Is the inspection result normal?
YES >>GO TO 3.
NO >>GO TO 2.
-
-
CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT
-
Turn ignition switch OFF.
-
Disconnect IPDM E/R harness connector.
-
Check the continuity between A/F sensor 1 harness connector and IPDM E/R harness connector.
A/F sensor 1
IPDM E/R
Continuity
Connector
Terminal
Connector
Terminal
F12
4
F96
75
Existed
Is the inspection result normal?
YES >>Perform the trouble diagnosis for power supply circuit.
NO >>Repair or replace malfunctioning part.
-
-
CHECK A/F SENSOR 1 HEATER OUTPUT SIGNAL CIRCUIT
-
Turn ignition switch OFF.
-
Disconnect ECM harness connector.
-
Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
A/F sensor 1
ECM
Continuity
Connector
Terminal
Connector
Terminal
F12
3
F25
126
Existed
-
Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >>GO TO 4.
NO >>Repair or replace malfunctioning part.
-
-
CHECK A/F SENSOR 1 HEATER
Refer to Component Inspection.
Is the inspection result normal?
YES >>INSPECTION END
NO >>GO TO 5.
-
REPLACE A/F SENSOR 1
Replace A/F sensor 1. Refer to Exploded View.
CAUTION:
-
Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
-
Before installing new A/F sensor, clean exhaust system threads.
INSPECTION END
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Other materials:
Operation
Switch Name and Function
Switch Name and Function
STEERING SWITCH
The steering switch is located on the steering
wheel.
Transmits the steering switch signal to the
combination meter.
...
B1040-22 Vehicle Speed
Dtc Description
DTC Description
DTC DETECTION LOGIC
Note:
This DTC may be detected when drive the Nissan Sentra vehicle
at vehicle speed of 186 MPH (300 km/h) or more.
DTC No.
CONSULT sc ...
P2135 Tp Sensor
Dtc Description
DTC Description
DTC DETECTION LOGIC
DTC
CONSULT screen terms
(Trouble diagnosis
content)
DTC detection
condition
...