DODGE RAM FORUM banner

1 - 4 of 4 Posts

·
Registered
Joined
·
44 Posts
Discussion Starter · #1 ·
'05 5.7 SLT bone stock.


Daily driving 26 miles to work one way, never a code unless I romp it, especially in wet weather.


But consistently, after being driven 30 miles or more (one way) within 10 miles of restart, this thing will throw the P0404 code every time. If I tow a load, it'll do it within 15 miles.


Admittedly, I've replaced the EGR with aftermarket ones 3 times over the past 3 years. Even when the code is active, it idles and runs fine, no decrease in fuel mileage. I generally reset the code and keep driving. And have removed, checked and thoroughly cleaned the return tube. It was clean and the valves I've replaced were perfectly clean inside. (light gray like a well firing plug)


Somewhere I read a thread here that gave a possible alternative cause of a false 0404 code but cannot find it now. Seems they mentioned a MAP or MAF sensor issue. (?)


Any drivability gurus out there have a clue?
 

·
Premium Member
Joined
·
32,783 Posts
P0404 DODGE - Exhaust Gas Recirculation Position Sensor Performance

Possible causes EGR volume control solenoid valve
EGR volume control solenoid valve harness is open or shorted
EGR volume control solenoid valve circuit poor electrical connection
EGR temperature sensor and circuit

When is the code detected? An improper voltage signal is sent to ECM through the valve

This goes into greater detail
https://www.obd-codes.com/p0404
 

·
Registered
Joined
·
44 Posts
Discussion Starter · #3 ·
It's always when running at road speed (over 45) when it throws it.
I don't have a scan tool or buddy who has one either. I suppose I'll replace it again. I do have a DVOM, an old electronics O-scope, spare batteries and can find a variable pot in a junk bin around here somewhere so I can bench play with the old one(s).


Thank you for the link GT. That is one of the help pages I found and lost a couple years ago.
 

·
Registered
Joined
·
44 Posts
Discussion Starter · #4 ·
P0404 DODGE - Exhaust Gas Recirculation Position Sensor Performance

Possible causes ……..

When is the code detected? An improper voltage signal is sent to ECM through the valve

This goes into greater detail
https://www.obd-codes.com/p0404


Always when it's "warm" not necessarily up to temp. Yesterday, I drove 57 miles, shut off for 1.5 hrs. Within 3 miles of restarting (low speed, on edge of a town, no stops, max speed 40) threw the code. I stopped 5 miles later, reset and it's still off. I'm confident from earlier experiences that if it'd sit all night, it would not have set the code.


I found a web page of a lab that researches egrs and they heat them to running temps to read signal voltages on an O-scope. The differences between cold and hot are dramatic. So I'm going to assume it's a ragged sensor signal that ticks off my PCM and just replace it again. I found a local shop that offered to trace and read the signals, but for the cost of labor I can purchase 2 (aftermarket) valves. Swapping one out I can do in my sleep. :)
 
1 - 4 of 4 Posts
Top