code p1421 nissan 2009 versa/what is the problem

Question

my 2009 versa engine light keep coming on, what does that mean

Answer 1

If you have no drivability problem you may have to reprogram the ECM. There is a service bulletin for that problem that recommends reprogram the ECM. Unfortunately only the dealer can do that for you. See "Tech Notes" on the code page for bulletin information.

P1421 Nissan - Cold Start Control

Read more: https://www.autocodes.com/p1421_nissan.html

Answer 2

P1421- Cold start emission reduction strategy monitoring

ECM does not control ignition timing and engine idle speed properly when the engine is started with pre-warming up condition.

there is a service bulletin for an ECU update at the dealer (it might cost as much as $150) 

if the update has been done

Make sure your intake filter is clean if its dirty or has not been replaced in 15k miles replace it, after you clean the throttle body you can disconnect the battery (30min or so) to reset the ECU.

After you can also clean the throttle body and do an Idle Air Volume Learning

http://nissanhelp.com/diy/versa/projects/nissan_versa_idle_air_volume_learning.php

and

Throttle Valve Closed Position Learning

http://nissanhelp.com/diy/versa/projects/nissan_versa_throttle_valve_closed_position_learning.php

Other possible causes:

• Lack of intake air volume

• Fuel injection system

• ECM