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What is the normal voltage range for the EGR DPFE signal

Posted: Fri Jun 01, 2018 8:28 pm
by billbowie
I am getting a P0405 code when I scan it with Torque. The description says "Powertrain Exhaust Gas Recirculation Sensor 'A' Circuit low". I think this is referring to the DPFE voltage. Is that correct?

What is the allowable voltage range?
I was able to find multiple people talking about testing DPFE sensors. Some say whatever voltage they read is outside the allowable range and then they give various ranges of what good is on some vehicles but I can't find any place that lists that the range is for my vehicle.

I measured each pin at idle
Pin# Name Voltage
1 EVR 12V
2 VREF 5V
3 MAPI 1.3V but varies
4 VPWR 12V
5 DPFE 0.3V <-----
6 SIG_REF 0V

The car has almost 300K on it so I assumed it was a bad EGR valve so I replaced it. The issue resurfaced within about a month. It seems hard to believe the replacement has also failed in the same way as the old one.

Also is there a test procedure where I apply a vacuum and measure certain voltages at specific values like I found for old Ford MAP sensors?

2005 Freestyle limited AWD.

Thank you for any help

Re: What is the normal voltage range for the EGR DPFE signal

Posted: Sat Jun 02, 2018 4:19 am
by xvert
Did you read this article already (p. 51)? To determine the cause of the malfunction, a test in motion is required. But most likely the DPFE sensor is working. First I would clean and test the vacuum tubes between the EGR valve and the intake manifold,
PS I found bad electrical contact in my EGR valve.

Re: What is the normal voltage range for the EGR DPFE signal

Posted: Sun Jun 03, 2018 2:42 pm
by dmckmc
I've also experienced EGR trouble on a high mileage 2005 Freestyle LTD AWD. Mine was a short in the harness between the EGR and the PCM. The previous poster had electrical problems as well. It would be worth checking continuity of the of the harness wires to the PCM. The harness wiggle test would be in order. If necessary, the PCM is under the cowl, not too hard to remove. If you replaced your own EGR then you could manage removing the cowl I suspect.

DPFE reference range KOEO and Hot Idle is 0.5 to1.3 and is pin #E44 in the PCM.

Re: What is the normal voltage range for the EGR DPFE signal

Posted: Mon Jun 04, 2018 3:57 am
by billbowie
Thank you for the information. I will let you know what I find as soon as I get a chance to pull the PCM.

Re: What is the normal voltage range for the EGR DPFE signal

Posted: Sat Jun 22, 2019 7:28 am
by billbowie
finally did something about this. There was an intermittent short in the back of the engine. I decided to remove the intake and do spark plugs. This made everything easy to access. After fixing the short I was still seeing the code once in a while. The minimum voltage on the DPFE line is 0.2V. It was sometimes dropping to 0. I replaced the valve and all is good now.