P26C3
Internal Control Module Transmission Range Sensor Performance
The internal transmission range sensor inside the control module (used for redundancy on shift-by-wire systems) does not match the external sensor reading.
- 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.
- Internal sensor driftPossible
- External range sensor driftPossible
- Sensor element aged beyond calibration windowLess likely
Parts involved
- Control Module
- External Range Sensor
P26C3 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.