Nissan Maxima Service and Repair Manual: P050A, 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 or P050E is displayed with other DTC, first perform the trouble diagnosis for other DTC

Nissan Maxima. DTC DETECTION LOGIC

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.

2.PERFORM DTC CONFIRMATION PROCEDURE-I

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 "COOLAN TEMP/S".

With GST

Follow the procedure "With CONSULT" above.

3.PERFORM DTC CONFIRMATION PROCEDURE-II

With CONSULT

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

With GST

Follow the procedure "With CONSULT" above.

Diagnosis Procedure

1.PERFORM IDLE AIR VOLUME LEAR

2.CHECK INTAKE SYSTEM

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

  • Crushed intake air passage
  • Intake air passage clogging
  • Clogging of throttle body

3.CHECK FUEL INJECTION SYSTEM FUNCTION

Perform DTC Confirmation Procedure for DTC P0171, P0174.

4.PERFORM DTC CONFIRMATION PROCEDURE

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

5.REPLACE ECM

  1. Replace ECM.
    P0507 ISC system

    P0550 PSP sensor