I have a 2001 STS and lately the Traction Control and sometimes the ABS light have been coming on but they will clear if I turn the key off and restart. The codes I have are U1016, U1040, U1000, P1571 and P1644. What might be causing this?

 

This problem is most likely caused by a bad circuit. The U codes show the PCM and EBCM are not communicating and the P codes show there is a problem with two signals between them. It would help if you posted whether the codes are current or history and which modules are sending the U codes. Also because you have a U1000 code, it helps to know which modules are sending NO codes.

The traction control light comes on because the EBCM disables the TCS due to the problem with the requested and delivered torque signals.

Check the conductors for the delivered and requested torque signals:

Delivered torque signal: 12 volt from EBCM C2 pin 2 thru a tan/blk wire to PCM C1 pin 34. The PCM controls the signal to the EBCM by pulsing the ground.

Requested torque signal: 5 volt from PCM C1 pin 43 thru a orn/blk wire to EBCM C2 pin 12. The EBCM controls the signal to the PCM by pulsing the ground at 121-134 Hz.

If that doesn't fix the problem, check the power, ground, and communication circuits to the PCM and EBCM.

 

So, Seville. I'm experiencing a similar problem on my 2000 deville. Constant ABS light, followed by TC and BRAKE.
current codes are
NO ABS DATA
IPC U1000
IPM BO269
IPM B0429
PCM P1571
PCM P1644
PCM U1040
NO RCC DATA
SDM U1040

How do I check these circuits with a multimeter? And pulse with what? Do I need a Tech II to do this?