U0404 code

[Adam Reighard]

I have got a situation I am struggling with that I am looking for help with. I have talked to several people about this but have not tried the Renntech community yet.

I have a 2007 911 Targa 4s that I am getting some codes on. The car is in emergency mode and has the codes U0404 and P1702 in the ECM. The TCM has a 2602 code.

I have replaced the conductor plate on the valve body, cleaned the valve body out and checked all solenoids. All solenoids are within range on the ohms and all engage with 12v applied.

There was a leak from the transmission from the plug but not too bad. I replaced the plug and checked the ohm on all the wires after the harness was cleaned up. All checks out good.

I checked and cleaned all the grounds.

I had the TCM sent out to be checked and all hardware is good. I checked the ohms between the TCM and the ECM. 

I checked the shift lever indicator module and even tried another one.

I found some time of oil fluid running down the harness to the ECM but it did not damage the unit. I believe the fluid is coming from the lines for the targa. I cleaned the wire harness and everything checks out good.

I am really at a loss here.

 

The research that I have done on the U0404 code leads me to believe there is an issue in the software. I tried sending it to the dealer and told them I only want the ECM to be reflashed. They called me and told me they were having trouble reflashing the ECM because they could not get the VIN to write to the unit. Then they proceeded to check everything out and came back with a $37k estimate to fix it. They said the ECM, TCM, and the transmission needed to be replaced. 

 

Has anyone ever heard of someone having to deal with this? Any help would be greatly appreciated. 

[JFP in PA]

Welcome to RennTech

 

P1702 is for "an impossible bit combination" at the DME, which could be software or a transistor chip problem in the DME.  This is very problematic and probably why they could not get the unit to accept a reflash.

[Adam Reighard]

Since I don't have a PIWIS just yet so my options are limited. I do have another ECM that would work but I would have to code the ignition to it. I will check to see if anyone local can do it for me until I get mine.