Ford Focus EGR

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Ford Focus EGR

Postby Peter704070 » Tue Sep 30, 2014 6:15 pm

Hello we have a Ford Focus 1.6 Diesel (DV6TED) in our college workshop with a few fault codes. They lead back to a fault with the EGR valve;

P2142 EGR Throttle Control Circuit High

P0488 EGR Throttle Position Control Range/Performance

We got the scope out and tested the two motor wires (the wiring diagrams shows two wires for the motor so it must reverse the polarity) and also the signal wire back to the ECU - we checked the other two wires for the sensor and got a 5v supply and Earth. What we would like to know is should the pattern show the signal wire moving in a linear direction as the motor polarity changes. When we turn the ignition off or rev the engine the voltage on the signal wire drops from around 4v to 0.5v.

Any help would be great. Thanks Pete
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EGR Ford DV6TED REV.psdata
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Re: Ford Focus EGR

Postby tode » Tue Sep 30, 2014 7:40 pm

I think that the electrically egr valve has nothing, could be stuck or broken mechanically, but before removing it I would check the air mass values​​ with diagnostic tool, to a minimum with egr closed (loose connector) about 370/380 mg/cp (41 Kg/h or 11 g/s) if the values ​​are different, perhaps lower egr stuck open, if higher maybe MAF dirt from the oil vapor.
In these engines the oil vapors are very strong and the MAF is near, and it gets dirty try to clean it with suitable spray gun and air, being careful not to break it, then double-check the values.
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Re: Ford Focus EGR

Postby Robski » Tue Sep 30, 2014 7:43 pm

You had a channel left, why didn't you deploy the low amps clamp (20A scale) for a fuller picture ?

But, buffer 6-7 shows a change in command (polarity) with the position signal staying high ! The current clamp would have shown the polarity (motor direction) change too.

PS yes a linear voltage transition.
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Re: Ford Focus EGR

Postby Fat Freddy » Wed Oct 01, 2014 11:46 am

You had a channel left, why didn't you deploy the low amps clamp (20A scale) for a fuller picture ?

But, buffer 6-7 shows a change in command (polarity) with the position signal staying high ! The current clamp would have shown the polarity (motor direction) change too.

PS yes a linear voltage transition.


X2

Also I would have put more time on the screen - the transitions would be more apparent and to keep file size down I would have reduced the sample rate. 7MS/s is a lot of samples.

HTH
FF
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Re: Ford Focus EGR

Postby hijakd » Sat Oct 18, 2014 9:41 am

Energize the egr valve and check that it's opening and closing,if it's stuck open you will have a rough idle/stall
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Re: Ford Focus EGR

Postby sigoaprendiendo » Tue Oct 21, 2014 8:43 pm

hijakd wrote:Energize the egr valve and check that it's opening and closing,if it's stuck open you will have a rough idle/stall


Hijakd is pretty right, is exactly what Mr. Danner would do
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