VOLTAGE ON N75 solenoid

[habibi]

Hi,

I am currently working to solve the limp mode issue in octavia 81kw diesel. While replacing hoses I have checked the voltage on the n75 solenoid connections and the voltage is around 8 volts. The same voltage is on EGR valve. I took the n75 off and checked it, the solenoid starts working from 9 volts. I presume this is not normal as the solenoid is not activated from 8 volts. Any ideas?

Thanks

[will_]

High impedance connection somewhere, maybe from corrosion or a loose connector? Earth problem?

Were you measuring with respect to battery 0v or directly across the solenoid connectors? First step would be to isolate whether it's the positive rail being pulled down or the earth rail floating up.

[habibi]

I was measuring directly to the connectors. Will try directly to the ground. May be the relay supplying the voltage is faulty.

[TeflonTom]

don't forget, when measuring the voltage on solenoids you have to counter in the resistance of the coil, besides, it wont show a constant voltage anyhow because the control signal from the ecu is pwm

[will_]

Oh, that's a point - if it's PWM, any reading you get with a multimeter will be pretty much meaningless. You'll need an oscilloscope.