DTC P1870: TRANSMISSION COMPONENT SLIPPING
PCM monitors difference between engine speed and transmission output speed. In D3 with TCC engaged, engine speed should closely match transmission output speed. In D4 with TCC engaged, TCC slip speed should be -20 to 50 RPM (all models except Corvette) or -20 to 40 RPM (Corvette). DTC P1870 is set if PCM detects excessive TCC slip when TCC should be engaged.
Action Taken By PCM
PCM performs the following if DTC is set:
Will illuminate MIL at second consecutive failure signal.
Inhibits TCC engagement.
Inhibits 4th gear if in hot mode.
Freezes shift adapts from being updated.
Commands maximum line pressure.
DTC P1870 will be stored in PCM history.
Monday, June 15th, 2009 AT 6:16 AM