Engine Speed Input Circuit
A general circuit fault on the engine speed signal that the TCM receives from the ECM. Without this signal the TCM cannot synchronise gear shifts to engine load.
Affected components
- Engine speed signal to tcm
Common causes
- High likelihood: Harness fault between ECM and TCM
Possible 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
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.