Vehicle speed sensor keeps going out

MCALISTER74

MEMBER
2008 PONTIAC G6
2.4L
4 CYL
2WD
AUTOMATIC
179,000 MILES

Car started shifting rough, speedometer fluctuating wildly. Changed VSS, worked fine for a while. Then began doing the same thing. Changed VSS (output) again. Was fine, again. Started doing same, bought and installed new VSS. Now speedometer isn't working at all, and power steering warning is on. Could a bad VSS connector be the issue, or maybe the input VSS? I have no idea how to proceed.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,748 POSTS

Hi,

Have you had the computer scanned to see what code is stored? There should be one related to this issue.

Now, I have a feeling this is a wiring issue rather than the sensor. Confirm that the connector is good, not damaged (the pins) and it is tight. If that is good, then the only way we can check if the sensor is bad is to check it. It will require a digital multi meter to check resistance. .

Output speed sensor resistance should measure between 1,650-2,200 ohms at 20°C (68°F).

As far as the input sensor, sensor resistance should measure between 820-1020 ohms at 20°C (68°F).

I need you to start there to see if it is a sensor or if we need to start tracing wiring.

Here are a couple links you may find helpful:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

Let me know what you find. Also, if you haven't had it scanned for codes, that is truly where I would start.

Let me know if you have other questions.

Joe