4 wire egr valve feedback

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4 wire egr valve feedback

Postby ian durston » Sun Mar 27, 2016 11:19 pm

Can anybody please explain how the feedback signal is generated on a 4 wire egr valve.the valve in question is fitted on a vaux zafira 2 litre Diesel engine code y20 dth. It has a power and ground a duty cycle control [battery volts] to ground and what looks like a duty cycle feedback [4.5 volts] to ground.i can't find any decent information anywhere.
ian durston
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Re: 4 wire egr valve feedback

Postby volrem » Mon Mar 28, 2016 10:40 am


Post a capture so others can see.

But you expained it already.

Power and ground. PWM control from ECM and digital feedback to ECM. Duty changes in relation to valve postion.

Signal is generated inside valve by little electronics module.
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Re: 4 wire egr valve feedback

Postby STC » Tue Mar 29, 2016 11:26 am

i can't find any decent information anywhere.

There is info out there, Autodata, Bosch ESi & Tis. Pin 2 comes from a fuse, 3 goes to earth. 1 & 4 go to the controller.

You don't say what Fault (code) you have, but I would have thought (for EGR) that Live Data & Component Actuations would initially be your best friends here.
A good scanner will have EGR Command, Pulse Duty, Reply & Air Mass and an actuator function.

You could (with powers & grounds confirmed) have the scope on pins 1, 4 & MAF signal, Amp Clamp on 2 or 3 as you actuate it for the pretty picture.
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Re: 4 wire egr valve feedback

Postby busjockey » Wed Mar 30, 2016 6:00 pm

A capture would be nice. Plus if you could post some scan data and codes. That way we can help you better. :)
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