I finally did the EBPV brake mod using the swamps method. I got a Cherry KM switch from Digi-key that lights green when on and red with brake pedal. Pretty cool actually. After it was all said and done and based on the following curiosity, I think if I could re-do it I would put the second diode after the switch so that the green light would come on whenever the PCM is sending power to the EBPV(although I'm wondering if there is always voltage present).

The curious thing is that I get voltage from the PCM to the EBPV plug at all times. Just using my multimeter on the wire coming from the pcm (thus not having anything to do with my wiring changes) I get full battery voltage. However the EBPV doesn't actually close when I plug it in. It does close and actuate with my switch sending power. I would think there should be no voltage to the plug.

Anyone ever test the voltage at the plug and notice if you get power at warm idle?

I am experiencing a lack of acceleration when it is hooked up so I'm gonna clean my EBP tube and sensor tomorrow.

 

Are you sure the EBPV works? It's possible when you have voltage at warm idle. up here in the cold north some trucks will close the EBPV while going down the road at full operating temp. It's possible your pcm is telling it to close but the coil is bad and it never closes. I also thought all control/PCM voltage was 6 votes not 12.

 

Can't edit my post, just saw you said it works with your switch. I don't have a clue what's going on.

 

Were did you ground you multimeter too? The converter lock solinoide always has power, the pcm grounds it. I better the EBPV is the same way.

 

Almost every sensor on a PSD either reads , or sends ground

 

Ahh. That would make some sense. I was just metering the 2 wires of the plug thinking one was just ground. I'll try B- or a diff ground in the morning.

 

maybe this'll help:
ECSD - Exhaust Back Pressure (EPR) Regulator - 1994-1997 Power Stroke FAQ

 

Wow that helps a lot. That is exactly what I was looking for. Thanks!

 

PCM sends a duty cycled ground to EBPV at 20 HZ rate. Therefor you can't measure it with a standard vom, except 1 side will always be 12 volts. Here is a diagram ...



One misled fact is the EBPV is either always open or always closed, far from the truth. Since the PCM duty cycles the device it is a percentage open / closed. If you watch EBP on a scanner you will see about 15 PSI at idle (valve open) and 43 PSI worse case (valve closed). Normal operation during those cold mornings will vary around 23 PSI and 39 PSI depending on engine demand (your foot on the go peddle). Once EOT hits about 175* then the EBPV operation ceases.

IMO another misleading fact is EOT and IAT both play a role it activating the EBPV on those cold mornings. Data indicates the IAT has preference over the EOT in all cases, with the exception when the EOT is above 175* then it rules. Engine can be warm, say EOT is 150*, you hit freezing fog, IAT goes below 32* ... bang EBPV starts operating again.

 

Dang .. bet me to it, but I had to type more.

 

Yes, but you have it in your memory and Rodney in his PC. LOL.