Operation CHARM: Car repair manuals for everyone.

Shift Point Signal

OPERATION
The Shift Point Signal is connected to pin B 13 of the Engine Control Module, the signal is directional IN only (PIN B 13 - INPUT ONLY).
The shift point signal comes from the automatic transmission control module (TCM).

PURPOSE
The Engine Control Module uses this signal to recognize upshifts and downshifts of the automatic transmission.
For additional shifting comfort, The Engine Control Module retards the ignition timing and therefore reduces engine torque during shift operations.

Self-diagnosis:
^ Self-diagnosis (OBD) recognizes a continuous signal (short to ground) as a fault. The signal is then no longer accepted.