Nissan Sentra manuals

Nissan Sentra Service Manual: P050A, P050B, P050E Cold start control

Nissan Sentra Service Manual / Engine / Engine control system / Dtc/circuit diagnosis / P050A, P050B, P050E Cold start control

Description

ECM controls ignition timing and engine idle speed when engine is started with pre-warming up condition.

This control promotes the activation of three way catalyst by heating the catalyst and reduces emissions.

DTC Logic

DTC DETECTION LOGIC

NOTE:

If DTC P050A, P050B or P050E is displayed with other DTC, first perform the trouble diagnosis for other DTC.

DTC No.

 CONSULT screen terms (Trouble diagnosis content)

 DTC detecting condition

 Possible cause
P050A COLD START CONTROL (Cold start idle air control system performance) ECM does not control engine idle speed properly when engine is started with pre-warming up condition.
  • Lack of intake air volume
  • Fuel injection system
  • ECM
P050B COLD START CONTROL (Cold start ignition timing performance) ECM does not control ignition timing properly when engine is started with pre-warming up condition.
P050E COLD START CONTROL (Cold start engine exhaust temperature too low) The temperature of the catalyst inlet does not rise to the proper temperature when the engine is started with pre-warming up condition.

DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.

  1. Turn ignition switch OFF and wait at least 10 seconds.
  2. Turn ignition switch ON
  3. Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.

>> GO TO 2.

2.PERFORM DTC CONFIRMATION PROCEDURE-1

With CONSULT


  1. Turn ignition switch OFF and wait at least 10 seconds.
  2. Turn ignition switch ON.
  3. Select “DATA MONITOR” mode with CONSULT.
  4. Check the indication of “COOLANT TEMP/S”.

Follow the procedure “With CONSULT” above. With GST


Follow the procedure “With CONSULT” above.

Is the value of “COOLANT TEMP/S” between 15°C (59°F) and 36°C (97°F)? YES >> GO TO 3.

NO-1 [If it is below 15°C (59°F)]>>Warm up the engine until the value of “COOLANT TEMP/S” reaches 15°C (59°F) or more. Retry from step 1.

NO-2 [If it is above 36В°C (97В°F)]>>Cool engine down to less than 36В°C (97В°F). Retry from step 1.

3.PERFORM DTC CONFIRMATION PROCEDURE-2

With CONSULT


  1. Set the select lever in N range.
  2. Start the engine and warm up in idle with the value of “COOLANT TEMP/S” between 15°C (59°F) and 40°C (104°F) for more than 15 seconds.
  3. Check 1st trip DTC.

Follow the procedure “With CONSULT” above. With GST


Follow the procedure “With CONSULT” above.

Is 1st trip DTC detected? YES >> Proceed to EC-339, "Diagnosis Procedure".

NO >> INSPECTION END

Diagnosis Procedure

1.PERFORM IDLE AIR VOLUME LEARNING

Perform EC-140, "Work Procedure".

Is Idle Air Volume Learning carried out successfully? YES >> GO TO 2.

NO >> Follow the instruction of Idle Air Volume Learning.

2.CHECK INTAKE SYSTEM

Check for the cause of intake air volume lacking. Refer to the following.

Is the inspection result normal? YES >> GO TO 3.

NO >> Repair or replace malfunctioning part

3.CHECK FUEL INJECTION SYSTEM FUNCTION

Perform DTC Confirmation Procedure for DTC P0171. Refer to EC-246, "DTC Logic".

Is the inspection result normal? YES >> GO TO 4.

NO >> Proceed to EC-247, "Diagnosis Procedure" for DTC P0171.

4.PERFORM DTC CONFIRMATION PROCEDURE

  1. Turn ignition switch ON.
  2. Erase DTC.
  3. Perform DTC Confirmation Procedure.

    See EC-338, "DTC Logic".

Is the 1st trip DTC P050A, P050B or P050E displayed again? YES >> Replace ECM. Refer to EC-485, "Removal and Installation".

NO >> INSPECTION END

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