# Sticky  How to manually pull and define ecu error codes.



## Nostrodomas (Jun 15, 2002)

How to manually pull and define ecu error codes.
Ok I know there are a few tutorials on how to do this but not many have detailed pics, and there are still questions on how to do or find stuff pertaining to doing this procedure. So I decided to go ahead and take some pics, and make up a noob free tutorial....lol

This tutorial is combined with the information from sentra.net, a little more info from me, and my pics.

Accessing the ECU should be similar for both the B13 and B14 Sentras. The paragraph below pertains to accessing the ECU on a B14, but should help B13 owners as well.

"Your ECU is located on the floor on the top of the hump between the drivers and passenger sides of the vehicle beneath the dash. There is a plastic cover over the ECU.








There are two plastic screws holding it to the ecu bracket. Remove the two screws and plugs. Then remove the cover. the cover is pretty stubborn, just take your time and wiggle it out.
Here you can decide if you want to try and reach the screw with out removing the ecu. It can be a PITA to do, but can be done, but for the easy route continue on.
Now you will see two gold nuts holding the ecu to the floor board.








Remove the two nuts. 








At the back of the ecu near the firewall, is a setting tab that is stuck into the floor board as well. You will need to pull the ecu over the bolts in front and then pull it towards the rear of the car.
Now that you have the ecu loose, pull the back of the ecu towards you. Now you should see something similar to this.








You adjustment screw may be hidden behind that sticker looking label. 
To retrieve the codes from your car's ECU, do the following:

With the engine off, turn the ignition to the ON setting. 
Turn the diagnostic mode selector on the back of the ECU fully clockwise. 
Wait two seconds and turn the mode selector fully counter clockwise. 
At this point the codes should begin to flash, and repeat. Meaning your service engine soon light, or check engine light will flash.

To determine the code number use the following rules to decode the flashes:

Long flashes (0.6 second) are the first digit 
Short flashes (0.3 second) are the last digit 
Example: A code of 12 would be 1 long flash and 2 short. A code of 55 would be 5 long and 5 short.
Once you have your error code(s), go here and define them. http://www.sentra.net/tech/ecu.php?
To stop the flashing code, turn the screw clockwise, wait 2 seconds, then turn screw counter clockwise.
To clear the code(s), repeat the last step one more time.


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