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Chris (aka-Moose)
Chris (aka-Moose), Technician
Category: Chevy
Satisfied Customers: 44398
Experience:  16 years of experience
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2000 suburban 1500 4x4 5.3l, speedometer / odometer and

Customer Question

2000 suburban 1500 4x4 5.3l, speedometer / odometer and cruise don't work, changed stepper motors and they are functioning, changed vss on tail shaft, no obd codes and no voltage at drk green/ white vss wire at odo, have steady 12.5 v at drk green/ white at body junction harness but does not vary with increase in vehicle speed, and obd scanner shows accurate vehicle speed thru obd port
Submitted: 11 months ago.
Category: Chevy
Expert:  Chris (aka-Moose) replied 11 months ago.

Welcome, I'm Chris (aka Moose) I'm an independent contractor here at Just Answer.

Since you get a accurate speed signal from the PCM but nothing else is getting the signal. That means its the PCM to blame not sending the VSS signal out.

Thanks for asking your question and letting me try to help you.

If you are unable to rate my response GOOD or EXCELLENT now. Please let me know why ( if I need to help more) and when you will be able to.

Follow up/Reply as many times as needed before or after rating.

Customer: replied 10 months ago.
the pcm was changed and coded to vin but the speedometer still does not work, is there anything else that would control the vss signal?
Expert:  Chris (aka-Moose) replied 10 months ago.

Are you sure the PCM is showing an accurate speed signal on a scan tool?

Customer: replied 10 months ago.
I have used 2 different autel's and an obd mx Bluetooth. All show an accurate mph. I also had the cluster tested and it checked out ok.
Expert:  Chris (aka-Moose) replied 10 months ago.

Does the cruise work?

Do you know how to check the VSS signal with a meter set to AC voltage at all the components getting a VSS signal?

See the link below.

https://dl.dropboxusercontent.com/u/90220402/VSS.png

Customer: replied 10 months ago.
No cruise. No ac voltage or sine wave. 12.5 volts DC with no pulse only before junction harness. No volts DC or ac after bcm to any component that uses vcc dk grn\ white wire. I have disconnected bcm plug ,verified voltage and run a jumper to the cluster plug but no vss signal. If you bump the jumper fast the speedometer will start to read so I take it that it uses a DC pulse signal not an ac sine wave. I am starting to think that I have a short to positive on the vss wire. Is it possible that the bcm is causing this?
Expert:  Chris (aka-Moose) replied 10 months ago.

Can you unplug all components on this circuit them OHM test this wire to power and ground and let me know if there is continuity?

Customer: replied 10 months ago.
Do you have a diagram of the vss. There are a lot of dk grn\ wht wires under the dash and at least 2 from ecm. I am about to cut the vss output at the ecm and cluster then run a new wire in between. Also do you know the reference voltage for the vss. That wire is showing 12.5 - 12.7 while the trucks at 14.2+ running
Expert:  Chris (aka-Moose) replied 10 months ago.

I sent a diagram last night at 9:41 central.

You unplug the PCM, instrument cluster, radio, cruise, BCM, suspension control module.