SOHC - 2.3L & 2.5L Lima Engines Discussions and Topics specific to the Lima 4 cylinder engines

P1401, P0402, P1405

  #1  
Old 2 Weeks Ago
Member
Thread Starter
Join Date: Oct 2015
Location: Texas
Posts: 36
P1401, P0402, P1405

On my way home today my truck threw a check engine light. The confirmed trouble code is P1401, DPFE sensor circuit high voltage detected. The PCM module also showed that code and two more codes: P0402 EGR "A" Flow Excessive Detected and P1405 Plugged or Open upstream Hi side DPFE sensor. Haven't performed any further diagnostics yet, but any insight on where to start would be helpful. The truck has 223k miles on it, and has the original aluminum DPFE sensor which I read can be faulty. Also the truck does ping sometimes which I am assuming could possible have something to do with the EGR system not being 100%.
 
  #2  
Old 2 Weeks Ago
RF Veteran
iTrader: (1)
Join Date: Jan 2014
Location: Vancouver, BC
Posts: 12,209
Yes, most common reason for those codes is that the DPFE sensor has failed in some way, because they do wear out from moisture intrusion.

The DPFE sensor works by having TWO exhaust hoses running to it from the EGR tube, these hoses can crack or break so should be looked at

Inside the EGR tube is an "orifice", plate with a hole in it

One of the DPFE hoses is farther away from EGR valve and on one side of the plate, the other hose is closer to the EGR valve and on the other side of the plate

As the computer opens the EGR valve the hose closer to the EGR valve has a pressure drop, the pressure difference between the two hoses is what the DPFE sensor reads and sends to the computer, so the computer knows how much exhaust is flowing thru the EGR valve and into the intake manifold.
DPFE = differential pressure feedback or delta pressure feedback


All exhaust has high water vapor in it, when you burn Hydrocarbons(H) with Oxygen(O) you get a by-product of H2O(water)
This is why exhaust systems rust from the inside out, lol, and why water drips from the tail pipe

So there is moisture in the DPFE hoses, because there is exhaust in the DPFE hoses, over the years that moisture can cause the DPFE sensor to fail


There may be another reason for the codes you have, but as a first step I would replace the DPFE sensor and check the hoses, if it is indeed the original 1995 DPFE sensor

The excessive flow could mean the EGR Valve is not closing all the way, this would cause a stumbling idle
The pinging would indicate lower flow from partially blocked EGR tube
These are not mutually exclusive, because if there was carbon build up over the years the tube gets clogged and valve can't close
 
  #3  
Old 1 Week Ago
Member
Thread Starter
Join Date: Oct 2015
Location: Texas
Posts: 36
I'll go ahead and replace the DPFE sensor. I notice there are 2 different versions of the DPFE sensor: Motorola 1.0 volt and a Kavilco 0.5 volt. Are these interchangeable or are they specific to the particular truck? The part number on my current one is F48E-9J460-BB.
 
  #4  
Old 1 Week Ago
RF Veteran
iTrader: (1)
Join Date: Jan 2014
Location: Vancouver, BC
Posts: 12,209
I would say 1995 would be 1volt version for sure
 
  #5  
Old 6 Days Ago
Member
Thread Starter
Join Date: Oct 2015
Location: Texas
Posts: 36
I replaced the DPFE sensor last night and cleared the code. This morning the check engine light came back with P1401 again. Using forscan itís showed the sensor voltage at 5 volts just like the last one did. Iím guessing either the new sensor is defective or I need to diagnose further.
 
  #6  
Old 6 Days Ago
RF Veteran
iTrader: (1)
Join Date: Jan 2014
Location: Vancouver, BC
Posts: 12,209
You will need to test the voltage at the sensor
Use a sewing needle to pierce one wire at a time so they can stay connected to the DPFE

Key on engine off
Brown/white wire should have 5volts, its the Power IN from computer, this wire powers several sensors

Grey/red wire should be a Ground, its the common reference ground for several sensors, but from PCM(computer)

Brown/light green wire, this is the money wire, lol, it should be sending back .8 to 1.2volt with engine off, this wires voltage is what you see on the Forscan

If brown/green is 5volts then unplug wires from sensor and test it again, it is still 5volts then the two brown wires are shorted together in the harness or possibly in the PCM

If brown/green wires voltage drops when its unplugged then yes, new sensor may be shorted inside
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
andy7
SOHC - 2.3L & 2.5L Lima Engines
4
11-05-2017 02:42 PM
ryan_88
4.0L OHV & SOHC V6 Tech
7
07-11-2017 07:27 PM
bucko
2.9L & 3.0L V6 Tech
2
12-01-2014 12:32 PM
Akuma
2.9L & 3.0L V6 Tech
1
02-08-2013 08:56 AM
texasfan1000
Drivetrain Tech
3
09-28-2008 07:33 PM


Thread Tools
Search this Thread
Quick Reply: P1401, P0402, P1405


Contact Us - Sitemap - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.