ABS alarms and trac off light up simultaneously

both lamps illuminate together

start can be ignited but sometimes off in the start sequence to reappear later.

What could be the cause?

Thank you for your help.


I read on the subject for the impala

 

it seems that this defect is related to one wheel speed sensor.

I do not see where these sensors are connected in the drawings.
How is localized the bad sensor with the TECH2?

The TECH2 is connected to the PCM (RS232 OBD2), but I see no connection between the PCM and the EBCM.

Thank you for your lights.
Speed sensor is in the gearbox .it seems.

 

My rear suspension is shot and my lights were coming on when I would hit a series of bumps, now they just come on at random. I'm assuming it is a wheel speed sensor with a chaffed wire, not in a big hurry to get under there though because it is now a third vehicle.

 

Took it in for an oil change a couple weeks ago. My indy does them quick and cheap and I get a good look from underneath while it's on the lift as well as some good conversation. Besides the rear shocks being totally wasted (passenger side is leaving puddles when it's parked), everything looks good from underneath.


So today I got around to replacing the rear shocks (Monroe MA-824, ~$70 from O'Reilly's, <1hr) and after had to take a spin to see how it felt...recently got a Autel AL619 so I hooked it up and it is getting bad readings from the right front wheel speed sensor. I'm gonna have to check the warranty on that one, it was replaced just over 2 years and only 15K miles ago.