OD light flashing, bad OSS sensor?

[Hillbillyshakespeare]

Trying to diagnose a potentially bad OSS. This is code it’s throwing. I added a link to the video of my Forscan pids. You can see the OSS has no reading in first gear and doesn’t want to shift. I let off the throttle and it finally shifts to second and I start to get an OSS reading and then the OD light starts flashing. I’m assuming that’s not how the sensor is supposed to work?

https://youtu.be/h9GsuX-ukdQ

 

[Mark Kovalsky]

That is not how the sensor is supposed to work.

What is happening is that when you see the OSS reading the PCM has calculated what the OSS should read and substituted that in place of the actual reading.

You have either a bad OSS or a damaged wire between the PCM and the OSS. My money is on the wire, not the sensor.

 

[Hillbillyshakespeare]

That is not how the sensor is supposed to work.

What is happening is that when you see the OSS reading the PCM has calculated what the OSS should read and substituted that in place of the actual reading.

You have either a bad OSS or a damaged wire between the PCM and the OSS. My money is on the wire, not the sensor.

Well the sensor will be here Monday. I’ll put it in and see if there is any change. If not I will trace the harness.

I just thought it was weird the VSS and OSS had no reading until i let off and it shifted to 2nd.

 

[Mark Kovalsky]

I don't think it's weird at all. The software determines that the sensors are not reporting, so it goes into failure mode. In failure mode it calculates what the sensors should be reporting and uses that to make the shifts happen.