Dtc Description

DTC Description

To judge malfunctions, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1 signal fluctuates according to fuel feedback control.

DTC DETECTION LOGIC

POSSIBLE CAUSE

• Harness or connectors (The A/F sensor 1 circuit is open or shorted.)

• A/F sensor 1

FAIL-SAFE

Not applicable

Confirmation Procedure

Confirmation Procedure

1. 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.

   Will CONSULT be used?

   YES >>

   GO TO 2.

   NO >>

   GO TO 6.

2. CHECK AIR FUEL RATIO (A/F) SENSOR 1 FUNCTION

   With CONSULT

   1. Start the engine and warm it up to normal operating temperature.

   2. Select “A/F SEN1 (B1)” in “DATA MONITOR” mode of “ENGINE” with CONSULT.

   3. Check “A/F SEN1 (B1)” indication.

   Does the indication constantly fluctuate around 2.2 V?

   YES >>

   GO TO 3.

   NO >>

   Proceed to DTC Diagnosis Procedure.

3. PERFORM DTC CONFIRMATION PROCEDURE-1

   With CONSULT

   1. Select “A/F SEN1 (B1) P1276” of “A/F SEN1” in “DTC WORK SUPPORT” mode of “ENGINE” using CONSULT.

   2. “TESTING” is displayed on the CONSULT screen when the following conditions are met.

      ENG SPEED	850 – 2,300 rpm
      VHCL SPEED SE	More than 64 km/h (40 mph)
      B/FUEL SCHDL	1.0 – 8.0 msec
      Selector lever	D position

      CAUTION:

      Always drive Nissan Sentra vehicle at a safe speed.

   Is “TESTING” displayed on CONSULT screen?

   YES >>

   GO TO 4.

   NO >>

   If “TESTING” is not displayed after 20 seconds, GO TO 2.

4. PERFORM DTC CONFIRMATION PROCEDURE-2

   1. Release accelerator pedal fully.

      Note:

      Never operate brake pedal when releasing the accelerator pedal.

   2. Confirm that “TESTING” change to “COMPLETED”.

   Is “COMPLETED” displayed on CONSULT screen?

   YES >>

   GO TO 5.

   OUT OF CONDITION>>

   GO TO 3.

5. PERFORM DTC CONFIRMATION PROCEDURE-3

   Touch “SELF - DIAG RESULT”.

   Is “OK” displayed on CONSULT screen?

   YES-1 >>

   To check malfunction symptom before repair: Refer to Intermittent Incident.

   YES-2 >>

   Confirmation after repair: INSPECTION END

   NO >>

   “NG” proceed to DTC Diagnosis Procedure.

6. PERFORM COMPONENT FUNCTION CHECK

   Without CONSULT

   Note:

   Use component function check to check the overall function of the A/F sensor 1 circuit. During this check, a 1st trip DTC might not be confirmed.

   1. Start the engine and warm it up to normal operating temperature.

   2. Shift the lever to suitable position and drive for a few minutes at 80 km/h (50 MPH).

      CAUTION:

      Always drive Nissan Sentra vehicle at a safe speed.

   3. Release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (31 MPH).

      Note:

      Never apply brake when releasing the accelerator pedal.

   4. Repeat steps 2 and 3, 5 times.

   5. Stop the Nissan Sentra vehicle, turn ignition switch OFF and wait at least 10 seconds.

   6. Restart the engine.

   7. Repeat steps 2 and 3, 5 times.

   8. Stop the Nissan Sentra vehicle and 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

Dtc Diagnosis Procedure

DTC Diagnosis Procedure

1. CHECK AIR FUEL RATIO SENSOR 1 POWER SUPPLY

   1. Turn ignition switch OFF.

   2. Disconnect air fuel ratio (A/F) sensor 1 harness connector.

   3. Turn ignition switch ON.

   4. 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.

2. CHECK AIR FUEL RATIO SENSOR 1 POWER SUPPLY CIRCUIT

   1. Turn ignition switch OFF.

   2. Disconnect IPDM E/R harness connector.

   3. 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

   4. Also check harness for short to ground and short to power.

   Is the inspection result normal?

   YES >>

   Perform trouble diagnosis for power supply circuit.

   NO >>

   Repair or replace malfunctioning part.

3. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT

   1. Turn ignition switch OFF.

   2. Disconnect ECM harness connector.

   3. 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	1	F25	86	Existed
      	2		88

   4. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector and ground.

      A/F sensor 1		Ground	Continuity
      Connector	Terminal
      F12	1	Ground	Not existed
      	2

      ECM		Ground	Continuity
      Connector	Terminal
      F25	86	Ground	Not existed
      	88

   5. 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.

4. REPLACE A/F SENSOR 1

   Replace malfunctioning 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