I keep pulling the code 1405, but I can't find what it is. I can reset the check engine light, but it will come back on in a day or so. I took the car in for a tune up, they said the code comes back as "undefined". But, this code has to have some definition, as it keeps tripping the check engine light.

Anybody know what 1405 is??

Thanks, help end my frustration!!

 

Sounds like the shop you took your Explorer for a tune up does not have a professional scan tool, capable of reading and defining manufacturer-specific diagnostic codes.

Assuming the code they pulled was for the powertrain and actually a P1405, the code is defined as (per the Factory Service Manual):

Diagnostic Trouble Code (DTC) P1405 indicates that Continuous Memory Self-Test has detected the exhaust manifold side (upstream) differential pressure feedback D.P.F. EGR sensor pressure hose is off or plugged.

Possible causes:

-- Improper upstream pressure hose connection.

-- Upstream pressure hose plugged.

-- Plugged or damaged pressure pickup tubes.
----------------

The DPFE on these vehicles is a known issue, but you might be lucky enough that it's just a bad hose for the DPFE.

-Rod

 

Usually the consequence of getting this code ((DTC) P1405) is eventually a cooked DPFE.

When the hoses are good the exhaust gasses are monitored by the difference in pressure across a gate in the exhaust manifold (no flow).

When one of the hoses is compromised, gasses are permitted to flow into the DPFE via the good hose (no back pressure), resulting in extremely hot gasses flowing through the sensor.

 

Great, thanks guys! Which hoses are these that I'm looking for? I found once a definition of upper pressure hose loose, but I have no idea what that is.

 

The rubber hoses on the DPFE. I would suggest inspecting both, even if the code is only pointing towards the upstream hose.

-Rod

 

Check this out....

DPFE Sensor and EGR Information - Focus Hacks

 

Thanks, guys! This is exactly what I needed. Aquanaut, that is GOLD!!! Thanks!

 

I just had that code on my 99 Mustang. Hoses on and in satisfactory condition. I had never seen one of the EGR tube to DPFE nipples stopped up so I doubted that but pulled the hoses and checked. Stopped up and hard as a brick! I took my little carb jet hand drill and put in as big a bit as I could fit in it and drilled that nipple out. The rest of the carbon chipped out pretty easily once I had a hole through it. Code gone!

Moral of that story ...... pretty darn accurate code that P1405 is!

The DPFE sensor codes on my F150 and most others I've worked on was the P0405.