We need to find out what the PCM is seeing as the vehicle speed. We can do this with a scan tool because if the PCM is seeing the proper vehicle speed then we know the speed sensor is operating. The PCM takes the output speed sensor signal and converts it to MPH and then sends it the BCM. The BCM then sends this info to the cluster to be displayed.
So this means we could have an issue with the PCM, BCM, cluster, or the wiring. We need to start with what the PCM is seeing and then use the scan tool to monitor the voltage in the BCM. If each of these are seeing the vehicle speed then they are operating and we can continue through the system.
Also, we need to check for codes just to make sure there are no circuit issues.
https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing
Below is the detail on how this operates. Let us know what you find with this and we can go from there. Thanks.
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Tuesday, April 27th, 2021 AT 8:52 AM
