Questions on 98 tahoe. the sensors for the anti-lock brakes, are they on all wheels, or just on the

…front of the vehicle? and can a scan determine which one is faulty? if they are located in the rear wheels are they generally
less expensive to repair? thanks in advance.

You have 3 sensors.
1 each for the front front brakes
1 on the transmission
A scanner should help greatly in determining which one is faulty. If you’re lucky a fault code has already set. Make sure that scanner does ABS codes and data.
A digital multimeter can also help. To check that way, you would be checking AC voltage (I believe)
while spinning the appropriate tire/driveshaft.

@db4690
ABS sensors dont work if they are not on all wheels normally. Is the tahoe that different? This should be a second gen scan system and the dealer can scan to find the faulty sensor. Some generic scanners may also see the ABS codes but this is not universal. Try getting a free scan on the car at a chain autoparts store and see if their scanner has the chevy extended codes.

Well, I don’t suppose this will help, but some vehicles only have ABS on the front wheels. (ex. my 1996 Dodge van)

I’ve never heard of ABS only for the front wheels, but I have owned three trucks that only had ABS on the rear wheels ('88 Chevy 2500, '93 Chevy 1500, '98 Ford F150). Rear ABS is supposed to prevent the rear wheels from locking up, which can cause the vehicle to spin.

mark9207, You are right, I messed up. (first time in a long time).

most of the time the rear wheel sensor is in the rear diff…