1999 Cadillac STS ABS TRACTION CONTROL

Do you perhaps have a diagnostic code number, or fault that they have referenced. The steering position sensor is a common fault. If you don't know the code, I can walk you through getting it from the vehicle itself.

With the key on, press and hold the info button up, and the on/off button together until the segments light up. At that point it should read ALL? On the info center. Press on/off again and it should change to ALL CODES, press the on/off again. The first codes to display will be for ABS and continue alphabetically through each module, we are only concerned with ABS. After you receive the codes, reply them to this post.

3 of the four codes point to the EBCM(brake module), and/or the brake pressure modulator valve. The C1217 is pump motor relay contacts open. That relay is integral to the EBCM. The C1242 1nd 1243 is pump motor open, and pump motor stalled, respectively. The fact that these lights came on after hard braking, was probably the pump was commanded on and was inoperative. There is a ground stud at the end of the pump motor case, and the ground lead connects to the trans housing. Make sure them grounds are tight. I believe you can disconnect the pump leads from the EBCM, and check continuity(resistance). The C1221 code was for LF speed sensor input = 0. With the procedure for reading codes I gave you, you could clear them all. Drive the vehicle until the ABS light comes on, and see which codes return. They will all turn on the indicator.

ABS and Traction control are integrated, both lights will go out.

As I stated previously, the pump motor is part of the BPMV. The pump motor relay is part of the EBTCM. The two of them are connected together, but serviced seperately. A salvage yard would probably sell them both as a unit of a tenth of the cost new.