Dc voltage

George

 

EGR unplugged:
Meter to battery ground
Red wire 12.06v
White wire .01v
Meter from white wire to red wire 12.02v

EGR plugged in:
Meter to battery ground
Red wire .01v
White wire .01v
Meter from white wire to red wire 0.00v

​​​​​​While I had it unplugged I went ahead and measured resistance between A and E on the EGR itself, and it's good at 8.5 ohms. Where is my 12v disappearing to when it's plugged in? I'm totally confused.



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Ok so now we need to measure the voltage on the red wire at the pcm (back probed) first with the Egr unplugged and then with the egr plugged in. Black meter lead to battery ground, dc volts. Do you have the wiring diagram?


George

 

The red wire from the EGR valve connects to the VCM on C4, pin 16


George

 

I think you posted the wiring diagram back near the beginning. I'll have to look but pretty sure C4 is where I have to unbolt pcm to reach it. Will post back when done.

 

C4 pin 16 red wire. Egr plugged in .01v. Egr unplugged 12.06v.

 

Sure wish someone else who has same EGR setup would pop in and tell me their voltages 😉

 

OK so the voltages that you are seeing at the egr are the same at the computer so the wiring appears ok even under a load. You mentioned measuring the egr control coil resistance and thought it was ok. Do you know the spec on that value?I want to make sure that the egr coil is not overloading the computer drivers.

my 2002 does not have an egr so I can’t confirm these values with you and resultantly there is no reference to that egr code in my shop manual. I have reached out to a member that may be able to provide us with some info on the operation of that valve and the expected voltages on those two wires. I expect those voltages to change because that’s how the Pintle position changes but one site I found suggests that 12v on red should be constant.

I’ll let you know what I find out.

George

 

Resistance was between A and E on the egr valve itself (terminals where red and white plug in). I read that should be 8-9 ohms and mine was 8.5. Every test I find says that red should be 12v constant plugged in or not. I did see one thing to check resistance between E teminal (red) and the egr casing which I haven't done yet. But that sounds like it might show there's an internal short on the E terminal, right?

 

I finally saw that 8-9 ohm coil resistance spec myself so 8.5 ohms is perfect.

Yes you can measure the resistance between both A and then E to the case and to the sensor ground (black),

Have you tried a drive test while watching the sensor output voltage to see if it moves off of the starting value of <1V?

George