speed sensor testing new GMs

wfstewart · Post by **wfstewart** » Fri Feb 02, 2024 5:08 pm

ok so I attached wiring diagram for a Inductive Type Sensor– 2-Wire and hooking the Pico up to crk 830,872,884,882 then ground lead to negative cable. I cannot get a signal out. the vehicle itself does read the sensors but the Pico does not. Now there is no fault in the system we are just teaching students how to test. this is a 2023 Sierra we have next to it a 2023 Camaro same system it will read. does anyone have any ideas why some would some wont are any ideas other was to test the system using a scope?

thanks for any ideas and advise
bill

victor2k · Post by **victor2k** » Sat Feb 03, 2024 12:50 pm

Hello,
Look here and you will find the answer:
https://www.picoauto.com/library/case-s ... -low-speed
And here you will find the needed info about the clampmeter used in this measurements
topic9977.html?&p=30525&hilit=magnetoresistive#p30525
Best regards

Rfmotors1 · Post by **Rfmotors1** » Sun Feb 04, 2024 12:17 pm

Hi Bill, The wiring diagram is more likely for magnetoresistive speed sensor design. There is 12V power supply and the ground wire would be the signal wire. See this post where is also psdata. file attached which includes a math channel for speed graphic visualisation. viewtopic.php?t=22488 You can test it on your case then.

Also see this link as there is possibility your sensors are also directional. viewtopic.php?t=23182 Hope it helps you.
Regards, Roman

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