How to (secret to) fixing P1404 EGR code

Posted by: davmac

How to (secret to) fixing P1404 EGR code - 12/22/08 07:23 PM

Or how to force the ECM to relearn closed or zero after replacing EGR

Situation:
Service Engine Soon light is illuminated. The diagnostic trouble code is P1404.

Repair info:
You can remove the EGR and clean the valve and passages thoroughly with brake cleaner or replace the EGR valve with a new or salvage part.

Problem:
After your repair you clear the code but the code keeps on coming back.

The issue is that the engine control module has to be forced to relearn the closed position (a zero reset) with the new or cleaned valve. The secret to getting the EGR valve to relearn the closed position is to clear the trouble codes with the valve disconnected and immediately turn the key off. The next time the ignition is turned on it will read the EGR signal and assume it is a closed position signal.

The order of repair is critical:
1. Remove and replace or clean the valve and reinstall.
2. Disconnect the EGR valve.
4. Connect the code reader, turn the ignition to on and clear codes.
5. Turn the ignition off and reconnect the EGR valve.
6. With the code reader connected turn the ignition on again and check codes. You may have to clear codes again if a P1403 code set because the EGR was disconnected the last time you cleared existing codes.

Posted by: Richard Candelario

Re: How to (secret to) fixing P1404 EGR code - 12/22/08 08:25 PM

good write-up. Thanks for posting this, I'm sure it will answer quite a few questions in the future.

Herc, Bobby, can we add this to the FAQs?
Posted by: 4drgt

Re: How to (secret to) fixing P1404 EGR code - 12/22/08 08:30 PM

or just use the tuner and tune out the code lol
Posted by: Zalfrin

Re: How to (secret to) fixing P1404 EGR code - 12/22/08 09:15 PM

better to fix the problem than to mask it...
Posted by: 4drgt

Re: How to (secret to) fixing P1404 EGR code - 12/22/08 09:50 PM

ahh its just the egr, id just take it off if it was broken