Disconnected VSS, Pulses from ECM?
Thread Starter
TECH Regular
Joined: May 2005
Posts: 406
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From: Bay Area, CA
Disconnected VSS, Pulses from ECM? 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.
Sometimes I really think I should have left the more powerful, simpler 400 in there.
Thread Starter
TECH Regular
Joined: May 2005
Posts: 406
Likes: 0
From: Bay Area, CA
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?
Also curious if I should be able to measure voltage to the VSS?
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
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.
I will try disconnecting my VSS tomorrow and see what happens.
Thread Starter
TECH Regular
Joined: May 2005
Posts: 406
Likes: 0
From: Bay Area, CA
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.
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.
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
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.
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
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.
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