Hey, im the new guy. I have a problem that is driving me crazy. My ranger 4x4 has right at 200k miles... engine light came on awhile back and said bad egr valve. So i changed it.... light came right back on. This time it said innsufficent egr flow. I saw that my main emmision hose was bad(collapsed) so i changed it too. Light came on again. This time i changed the DPFE sensor... well guess what? Light came on again!!! P1400 code: DPFE sensor low voltage detected. Now i have noticed that when i turn my ac to max my volt meter drops. So... Im at a loss here. I have no idea where to look for this problem. Anyone have any suggestions on how to fix this?

 

Im sorry. Put this in the wrong forum

 

No problem! Moved to the Ranger forum.

 

What year is your truck?
How does the truck run now?
When ever you replace these types of electrical parts, you must turn the computer "off" by disconnecting the battery.
Does you OBD2 scanner have a clear DTC clear function? Some codes have to be cleared.

 

Its a 2002. I had the codes read at Auto Zone. And I did dissconnect the battery. So I have no idea what to do at this point.

 

Welcome to FTE.

With the volt meter acting up, you may have more than one problem, so maybe consider running this puppy by your favorite autoparts store, for a no cost, in vehicle, electrical system check up (with all components in place in the vehicle), via their portable electrical system tester.

It can properly load test the electrical system & when expertly used, can spot all sorts of things, like weak or shorted battery cells, poor ground connections, bad battery cables, weak, shorted, or leaking alternator diodes, slipping drive belt ect, ect. So ask for their test guru so you get good test results!!!!

After getting the electrical system checked out & put right, then look to the EGR system & any other trouble code/s & post All of the code Numbers found.

Having the DPFE sensor on the suspect list is a good idea for that code, but maybe also look to the EGR systems vacuum swtching valve & lines between it & the EGR valve, which it controls by sending vacuum pulses on electrical command from the computer. So if the EGR's vacuum controling system has any vacuum leaks, it can affect how much EGR the engine gets.

Also if the vehicles B+ voltage is low, the computer can get confused about what it's supposed to do, as it's operation & it's sensors PID's to the computer can be corrupted by low battery/alternator voltage, so the computer can send faulty operation voltage to the EGR systems vacuum switching valve & other actuators, as well as getting bad data from it's sensors !!!! All a vicious circle!!!!

A bunch of thoughts for pondering.
Let us know what you find.

 

OK. I will try all of that. Im working alot this week but will try to git r done... thank you for the helpful advice

 

BTW, what brand parts did you use. I see a lot of guys with recurring EGR codes when they use aftermarket parts. The Ford Motorcraft parts are much higher quality and they meet the specifications perfectly. Aftermarket parts are simply imitations, but those companies do not know what the actual specifications are.

 

I cant remember the brand. I get all my parts from Rockauto.com, which are very reasonable compared to local stores. I did see a broke ground wire... but engine light came back on with same code. Will be checking the volts of the sensor now. And i do have a bad cell in my battery.