Pontiac Repair: ABS Wheel Sensor Test Procedure, digital volt meter, jumper wire

Question
QUESTION: Hey Todd, What is the procedure to test the ABS Wheel Sensor?  In this case, for a 2001 Grand-Am (Front Wheel Sensor).  The resistance in Ohms for example.  Also, what voltage/ground signals should be present at the jumper wire connector with the ignition on and/or the engine running?

ANSWER: Hi colin:

the resiatance for the sensor should be when the car is cold between 1000-1400 Ohms give or take a 100 or so. any more or any less there is ans issue. If you have a good Digital volt meter like a fluke meter check either one of the sensor wires to the knuckle where that hib is attached. the meter should read OL. anything other then that the sensor is shorted to the suspension of the car and the hube will need to be replaced. "Cheap" digital ohm meters will not pick up a short to the body of the car where there is literally Millions of Ohms of resitance. so don't go by an OL reading with a cheppie meter. as far as voltage it's ac volatge it produces. and it about 125-200 Millivolts turning the wheel by hand at a pretty quick rate.  good luck :)


---------- FOLLOW-UP ----------

QUESTION: Thanks for the tip.  From your answer, can I assume that there is no 5 volt feed to the wheel sensor from the ABS ECM?  I'm interested in checking for a break in the wiring harness that connects to the wheel sensor.

Answer
No there is no 5 volt refrence sent from the control module to the sensor. There is a refrence voltage sentbut it's misicule and I'm not sure what it is. It's just sent from the module during key on to make sure that the sensor is there. If you have an issue with a from sensor code the problem is either with the hib or the jumper harness going to the wheel. you can get the jumper harness from the dealer and they are not that expensive but they need to be spliced into the harness it has a plug on one end for the hub but just blunt cut wires on the other end that has to be sliced into the ABS harness.