neovalentine

About 2 months after I bought my car I got a P2404 CEL. Did some research and google fu and found most people suggest replacing the N80 Valve. Did that and CEL is still there. Took the car to a local Audi only shop, they did a smoke test, tested the sensors and everything was within range and no leaks detected. Some more googleing has found that a few people have gone all the way to replace the ECU to fix this issue. My smog is due at the end of the month and I'm running out of time to fix this. Has anyone actually fixed the P2404 error and was is the ECU or is there something else to try before I go that route? And if I do how hard is it to replace the ECU? Do I need to take it to Audi or is it simply plug and play?


Thanks,
Ron

neovalentine

oh and I did take it back to the dealer, they said it's as is no warranty and to **** off (Capitol Mitsubishi) It's also a 2006 A4 3.2 V6 Quattro.

milan_o

Did you get this resolved?

neovalentine

Nope! replaced gas cap, the n-valve, did smoke and leak down tests, traced the lines. My mechanic thinks it's the ECU now.

transae

I'm still trying to fix too. I've ignored it until it had to be smogged. Replaced the stupid LDP twice. Did the smoke test. That wasn't it. Luckily I only paid 350. I have no clue. I think I may say F the smog test.

neovalentine

It was the ECU. I had to get one off ebay.

Dolamite

It went from a evap code to needing a new ECU? How in the world does this happen. These cars never cease to amaze me. Well good to see you got things fixed.

frankinstyn

Has the code come back? How long has that fix held? I'm so tired of this code.

neovalentine

The Audi mechanic explained it like this. The ECU has a bad ground, but it won't trigger a CEL. The Bad ground stops the Evap Pump from working, which in turn stops the Evap Pump Solenoid from going. But since these are only used on start up, on cold mornings, or during certain times the error may not show up till the pump burns out, after the pump burns out the pump solenoid will go bad, then trigger the p2404. If you replace the Evap Pump but it still doesn't turn on in the ECU is bad. So in turn you'll need to replace the ECU. I replaced mine and the lights been gone. I check it daily with my OBD II logger and no codes are pending or showing.

Hope this helps.

Ron

mtboulder

On my 2003 Audi TTQ I had the P2404 code. I would clear the code and it would come back within two days. I tried replacing the V80 purge valve with no change. Finally I decided to test the V144 valve thingy located under the passenger side front wheel cover. This device measure the pressure in the EVAP system. I tested the device with an ohm meter per the Bentley manual and everything was in spec. When I went to replace the connector I noticed that one of the pins was corroded. I cleaned it up and reinstalled, cleared the fault code and it's been over a week and it has not returned. My guess is that the corroded pin gave a higher resistance reading than what the CPU expected and this caused the code failure.