Cruise control and neutral safety switch

69hurstolds

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Jan 2, 2006
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I've tried that but it still shows nothing and it's a brand new vss sensor from g body parts
What color is the box? Green or yellow? It needs to be green. GM p/n 25007463.

The chance of a "faulty" park/neutral switch is 1 in 10 zillion. Misadjusted? Maybe. But bad? Likely not.
 
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Built6spdMCSS

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Jun 15, 2012
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Even then the switch comes into play when you're trying to start the car, not when the key is in the normal RUN position. Not even sure why they have it in that diagram.

When the car is in gear that switch is open...

EDIT: OP calling things by the wrong name why I'm tracking on what I am.
 
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90hurst/oldsguy

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Jan 31, 2013
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What color is the box? Green or yellow? It needs to be green. GM p/n 25007463.

The chance of a "faulty" park/neutral switch is 1 in 10 zillion. Misadjusted? Maybe. But bad? Likely not.
It's definitely green I know the yellow is for digital instrument panel
 

69hurstolds

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Jan 2, 2006
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Ok, good. This means that you shouldn't throw a code 24 at the wrong time when the ECM "thinks" you're in Park or Neutral and driving down the road. Otherwise, the ECM could care less what other gear you're in.

Clear all your codes before doing anything related to the VSS. A code 24 that sets when you're not moving doesn't count. Most of the time when a speedo cable breaks or comes loose and you're driving around is when you usually get a 24 code.

Speedometer working ok.
Lift drive wheels and support rear axle so the car can spin the wheels without going anywhere. SAFETY FIRST. Be extra careful if you do this in your garage or close to other objects/cars.
Backprobe CKT 437 and be ready to check for voltage to ground
Start car, let idle, and place in drive. Voltage should vary from 1 to 6 volts.

If it's <1 Volt, there's a short or poor connection at the ECM. If it's 8-12 volts and steady, you have an open somewhere in CKT 437. If it's not shorted or open, it's likely a faulty VSS. If it is 1-6 volts, everything is working as expected.
 
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90hurst/oldsguy

Greasemonkey
Jan 31, 2013
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Ok, good. This means that you shouldn't throw a code 24 at the wrong time when the ECM "thinks" you're in Park or Neutral and driving down the road. Otherwise, the ECM could care less what other gear you're in.

Clear all your codes before doing anything related to the VSS. A code 24 that sets when you're not moving doesn't count. Most of the time when a speedo cable breaks or comes loose and you're driving around is when you usually get a 24 code.

Speedometer working ok.
Lift drive wheels and support rear axle so the car can spin the wheels without going anywhere. SAFETY FIRST. Be extra careful if you do this in your garage or close to other objects/cars.
Backprobe CKT 437 and be ready to check for voltage to ground
Start car, let idle, and place in drive. Voltage should vary from 1 to 6 volts.

If it's <1 Volt, there's a short or poor connection at the ECM. If it's 8-12 volts and steady, you have an open somewhere in CKT 437. If it's not shorted or open, it's likely a faulty VSS. If it is 1-6 volts, everything is working as expected.
Yes speedometer works fine just bounces a little bit. I have backed probed the ckt437 and there no voltage there . I see that this wire goes out the car through the wire loom. So I'm wondering if it shorted some where
 

69hurstolds

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Jan 2, 2006
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Disconnect CKT 437 at the VSS. If you get 10 volts or more at CKT 437 then, the VSS is faulty. If still no voltage after disconnecting, check the 437 wire to ensure it's not grounded/shorted somewhere else.
 

90hurst/oldsguy

Greasemonkey
Jan 31, 2013
148
7
18
Disconnect CKT 437 at the VSS. If you get 10 volts or more at CKT 437 then, the VSS is faulty. If still no voltage after disconnecting, check the 437 wire to ensure it's not grounded/shorted somewhere else.
I should have stated that I did this test at the ecm connectors. I know for a fact that the vss sensor has 12v when I installed the new sensor
 

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