P0727
Engine Speed Input Circuit No Signal
The transmission control module receives no engine speed signal. Required to coordinate shifts and torque converter lockup with engine state.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Common causes
Ordered by how often each turns out to be the cause.
- Speed signal lost on data busCommon
- Bus communication faultPossible
Parts involved
- TCM
- ECM
- Canbus
P0727 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.