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JHoop, Chevy Technician
Category: Chevy
Satisfied Customers: 5446
Experience:  14 Year Engine Builder,16 years as a Tech HvyLine, Suspension, Electrical, Brakes, 6 Year Shop Owner
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Chevrolet k1500 speedo on 92 chevy 1500 4x4 dont work have

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speedo on 92 chevy 1500 4x4 don't work have replaced sensor and cluster no luck also won,t shift into overdrive any ideas
Hello , my name is XXXXX XXXXX thank you for choosing Please tell me all the problem as my answers are based on the information you provide.

Does the engine light come on?
Customer: replied 6 years ago.
engine lite comes on
If the engine light comes on the ECM is not seeing the signal from the sensor. Neither is the cluster. If both wires at the speed sensor are good to the ECM then the nylon gear in the transmission tailshaft housing is stripped and needs to be replaced.

Make sure you use the right color nylon gear for speedometer accuracy.

If you have any more questions or need diagrams or service info, please don't hesisitate to ask If this answer helped you, please click ACCEPT.

Please leave positive feedback. As you can see I have excellent ratings in all my categories. Please remember I am not at the vehicle, Please don't leave a negative report. Thanks again, JHoop
Customer: replied 6 years ago.
no nylon gear it has a metal gear for the sensor
You have a 700 R 4? 4L60E?

What transfer case do you have?
Customer: replied 6 years ago.
700r4 tranny new process case
And the sensor screws into the output shaft housing on the transfer case?
Customer: replied 6 years ago.
Have you checked for an AC signal from the sensor while on a rack in gear? At the PPL/WHT and LT GRN/BLK wires from the sensor?
Customer: replied 6 years ago.

yes it changes with speed


OKI. Those same two circuits need to be checked at the ECM. Need the pin-outs?
I jumped a step here. Do you know where the DRAC buffer is? Behind the glovebox?
Customer: replied 6 years ago.

whats it look like

It is rectangular and has two plugs. 8 wires
Customer: replied 6 years ago.
ok now what
Check for power with the key in run CKT 250. Check for ground CKT 450 Check for AC signal at CKT 821 and one lead of the DVOM to 822. What ya got?graphic

Edited by JHoop on 1/3/2011 at 10:52 PM EST
REVISED........Check for power with the key in run CKT 250. Check for ground CKT 450 Check for AC signal at CKT 821 and one lead of the DVOM to 822. What ya got?

Edited by JHoop on 1/3/2011 at 10:54 PM EST
Customer: replied 6 years ago.

i got 12 at250 and450 no reading at 821


No AC voltage reading with the DVOM leads hooked to 821 and 822 with the wheels turning?
Customer: replied 6 years ago.
I think i got .4 volts
We still need to be precise here. Once again was there a ground signal to CKT 450 at the DRAC buffer?
Customer: replied 6 years ago.
OK. We have power and ground to the DRAC buffer. You said earlier that the AC signal at the speed sensor changes with speed. Does it also change with speed at 821 and 822 tapped at the DRAC buffer? Those are the same wires.
Customer: replied 6 years ago.
the ac does not change at senser or buffer
You said the AC voltage changed at the sensor yesterday?
Customer: replied 6 years ago.
yes I did but its to hold probes and read meter at the same time but now they read the same and dont change
If there is no speed fluctuating AC signal generation from the speed sensor while the wheels are moving the sensor is bad. Follow me? Do you have the GM chart for code 24?
I uploaded the procedure in .pdf format here to justanswer. You can download it by clicking HERE and HERE. I hope this helps you.

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