OldSchoolFormula

Well, disconnected my VSS and still get pulses from my ECM. Someone tell me this should be happening and that I'm not looking at replacing the ECM?

Sometimes I really think I should have left the more powerful, simpler 400 in there.

OldSchoolFormula

Can anyone disconnect their VSS and see if they get pulses through their speedo? I know you guys might not want to recallibrate your speedo's...

Also curious if I should be able to measure voltage to the VSS?

OldSchoolFormula

Anyone? Im really stuck out here. I do not get VSS codes when I unplug the darn thing so this would really help me narrow my possibility of a bad ECM down.

G-Body

iTrader: (4)

What year/make computer, harness, and trans are you using? Where do you currently have your speedo connected to? (PCM pin# and connector color, or connector # and pin #) What model SW gauge are you using?

I will try disconnecting my VSS tomorrow and see what happens.

OldSchoolFormula

Thanks G-Body.

Pin 50, red connector. 2001 PCM/Harness/motor, with a 2001 4L60E. Using SW model 114709 programmable 5" speedometer.

Got ahold of John Speartech through e-mail today, he said the PCM should not be sending out pulses with the VSS disconnected and he has no idea why it would be doing so.

G-Body

iTrader: (4)

Well you are hooked to the right wire, and I checked the directions for your speedo and they say it will accept square wave DC signals, so I`m confused, it should be working. The only thing I can think of right now is a bad ground.

G-Body

iTrader: (4)

I would try connecting a ground wire from your gauge directly to where you grounded the PCM, you could just run a temporary wire it would be a nice easy, cheap way to rule out a bad ground.

OldSchoolFormula

Tried just about everything. I need to find someone with an 01-02 A4 car and swap it in there to see if it trips out then. Really thinking its a bad ECM now.

RFERG43

You might try shorting the wires going to the VSS and see if the PCM output stops. If the VSS input to the computer is high impedance noise may be triggering the circuit.

OldSchoolFormula

I've tried putting the low side to ground, didn't change anything. Do you mean shorting the low side directly to the high side and seeing what happens? Any risk to the PCM?

RFERG43

Yes, short the low to high side. Since this is an input to the computer it won't hurt it.

OldSchoolFormula

Just gave it a shot... no change. Just counts away.