P01870 transmission component slipping. I've seen this problem come through my shop a few times. The lockup torque converter is slipping. The compueter reads engine RPM and trans RPM, the numbers should be almost, if not exactily the same. If it sees plippage more than 250 RPM (i think), it will set this code.I havent heard of an updated part to fix this but, people are always thinking. The last trans I had come in with this problem, I did a fluid and filter service and added Lub-Guard in the red bottle (it's the only trans additive I use) and they haven't been back sence. But it's my experince that once the converter starts slipping, it's only a mater of time before it fails. This won't necessarily cause the trans to fail complitily, but you will have too remove the trans to replace the converter. You probibily should rebuild the trans if this happens.