Circuit Description
The torque converter clutch (TCC) release switch is part of the automatic transmission fluid pressure (TFP) manual valve position switch. The TFP manual valve position switch is attached to the control valve body. The TCC release switch is normally-closed.
The switch signals the transmission control module (TCM) that the TCC is released. This is accomplished by torque converter release fluid pressure acting on the switch contact, thus opening the switch. When the voltage is high on the circuit, the TCM recognizes that the TCC is no longer engaged.
When the TCM determines that the TCC release switch is open, indicating that the TCC is not applied, and the TCC slip speed indicates that the TCC is applied, DTC P1887 sets. DTC P1887 is a type B DTC.