Mechanics

SPEEODMETER AND ODOMETER

1992 GMC Sonoma • 4 cylinder 2WD Automatic • 125,000 miles

My speedometer and odometer quit working. I replaced the speed sensor on trans. Checked resistance on the stepper motors in cluster. Replaced cluster. Check for voltage going to speed sensor plug=0. Also traced wiring back to firewall. What else can I do?
Avatar
Jestergmc
May 7, 2011.



I also cleaned plug with electrical cleaner and checked for voltage at the wire and plug.


Tiny
Jestergmc
May 7, 2011.
Raise rear wheels off ground place DVOM meter on AC scale trans in neutral. Rotate tires by hand @3mph meter shloud read.5 - 1 v AC


Docfixit
May 7, 2011.
Do I take the reading off the speed sensor? If it read good or bad what are the options?


Tiny
Jestergmc
May 7, 2011.
Yes reading off seed sensor this will tell if signal is being produced


Docfixit
May 7, 2011.
I got readings that jumped from 0 to 1.5 but had to turn the wheels at higher speed to get anything? So what does that mean?


Tiny
Jestergmc
May 10, 2011.
Is there something simple that I am missing?


Tiny
Jestergmc
May 10, 2011.
Find VSS buffer item F in first diagram on firewall near ECM. Check White Wire term.10 for output to speedo also check input signal from VSS


Docfixit
May 11, 2011.
I am having a hard time finding the VSS. Is it on the engine firewall or in the cab?


Tiny
Jestergmc
May 14, 2011.
Info I have firewall next to ECM


Docfixit
May 16, 2011.
Thanks. I found it and fixed it.


Tiny
Jestergmc
May 19, 2011.
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