PicoScope 7 Automotive
Available for Windows, Mac, and Linux, the next evolution of our diagnostic scope software is now available.
help identifying pattern
help identifying pattern
This signal is active on an output speed signal on a 2002 Toyota Prerunner with the vehicle stopped. the alternator and O2 are currently unplugged. this signal is telling the TCM that it is moving, anywhere from 6-128 mph. I am very new to the Pico/ scope world and have no idea what I am looking at. Thanks
-
Steve Smith
- Pico Staff Member
- Posts: 1593
- Joined: Sun Aug 25, 2013 7:22 am
Re: help identifying pattern
Hello and thank you for the post
My first thoughts turn to measurement error and I would like to clarify the set-up of the scope
I can see that only channel A is active, could you confirm the test lead signal wire was connected to the OSS signal/output wire and referenced to chassis ground?
Whilst I can also see the other channels are inactive, were any probes connected to the scope and if so, were they also connected to components on the vehicle?
If so, which components and were they referenced to chassis ground?
Moving onto the signal you have captured; we have a sporadic output crossing zero volts which could well be interpreted as a speed signal by an ECU
Given you have confirmed the TCM displays a MPH value when the vehicle is stationary, what happens when the OSS is disconnected?
Is this signal still present?
Forgive me here, I assume this signal is measured at the OSS, is the same signal present at the TCM if this sensor is hardwired to the TCM?
Given you are new to Pico this is a great capture and one that has certainly given you direction as there should be no output from the OSS when the vehicle is stationary
Sorry for all the questions and I hope this helps, take care…….Steve
My first thoughts turn to measurement error and I would like to clarify the set-up of the scope
I can see that only channel A is active, could you confirm the test lead signal wire was connected to the OSS signal/output wire and referenced to chassis ground?
Whilst I can also see the other channels are inactive, were any probes connected to the scope and if so, were they also connected to components on the vehicle?
If so, which components and were they referenced to chassis ground?
Moving onto the signal you have captured; we have a sporadic output crossing zero volts which could well be interpreted as a speed signal by an ECU
Given you have confirmed the TCM displays a MPH value when the vehicle is stationary, what happens when the OSS is disconnected?
Is this signal still present?
Forgive me here, I assume this signal is measured at the OSS, is the same signal present at the TCM if this sensor is hardwired to the TCM?
Given you are new to Pico this is a great capture and one that has certainly given you direction as there should be no output from the OSS when the vehicle is stationary
Sorry for all the questions and I hope this helps, take care…….Steve