Codes P0400 and P0403?

Tiny
MORGAN8173
  • MEMBER
  • 2019 FORD ESCAPE
  • 2.5L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 95,000 MILES
Okay, I’ve been dealing with P0400 and P0403, so I’ve replaced the EGR valve entirely along with the pigtail which all along I suspected that as the problem as over time the wires had hard bends through the wires, but it didn’t fix the problem so I replaced the EGR cause I kept trying to clean it. No luck! So, while taking the EGR off I noticed the transmission cooler hose connection was practically broken off from the cooler. So, I really expected that to be the issue at this stage cause prior I had T touched that cooler at all so the welds on them just gave way over time. No luck after replacing it. So, I once again look at live data not that I honestly understand what I’m looking at though, but I did notice the EGR command duty sat on 0% in park and while driving so it’s basic my dead or just simple not getting the power command signal, I assume. I’m going to attach the live data for you to see as well. So, prior to this happening I replaced the engine heater valve with the one that has a line hose connection because I have no heat in the car or all that didn’t fix the problem for the heat though I was told it would restore the heat. Probably the actuator in all honesty but I just haven’t gotten under there to pull it off to check. Do you think the wiring on tbar hearer valve could be the problem thou I do not get any error codes on it unless I have unplugged it or something. I honestly don’t know if my heater core is clogged or not.
Wednesday, September 20th, 2023 AT 6:15 AM

3 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,526 POSTS
We only handle one problem per thread, and it sounds like the heater problem is separate from the EGR code issue so that is what will concentrate on with this thread, please start a new question for the heater issue.

P0400 - Exhaust Gas Recirculation Flow Malfunction: This code indicates that there is a problem with the flow of exhaust gas recirculation in the EGR system.

P0403 - Exhaust Gas Recirculation Control Circuit: This code points to an issue with the electrical circuitry of the EGR system, specifically the control circuit.

So, if you already replaced the EGR valve it sounds like you have a bad connection for the EGR to the PCM. Here is a guide to help and the EGR and engine wiring diagrams so you can see which wires to test with the guide:

https://www.2carpros.com/articles/how-to-check-wiring

The wires at the connector look like they may be broken. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.
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Thursday, September 21st, 2023 AT 12:38 PM
Tiny
MORGAN8173
  • MEMBER
  • 69 POSTS
I was just giving you a run down of things I had done is all just to be up front in case any of those could be tied together with tbe 403 code mainly.

I’ve replaced the connector on the new EGR valve already. I’m about to double checking the wiring I made thou.

Specifically what other connector are tied together to the EGR that I should possible take a look at to verify their wiring to see if it’s broken by chance. There was a time in during this I was getting a misfire on cylinder 3 I checked the plug tighten it up and it went away. Do you think the wiring on the injector or coil could be the issue to 403?
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Thursday, September 21st, 2023 AT 1:16 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,526 POSTS
The code is for a circuit error so it must be the wiring or the EGR, if these are okay the only thing left is the PCM. Here is a generic guide to help you step by step with instructions in the diagrams below to show you how on your car, you can get a preprogrammed unit by searching Google or Ebay.

https://www.2carpros.com/articles/how-to-replace-a-vehicles-main-engine-computer-pcm-ecm-ecu

Check out the images (below). Please let us know how it goes.
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Saturday, September 23rd, 2023 AT 10:35 AM

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