P280A
Transmission Range Sensor A Circuit Not Learned
The TCM has not learned the calibration window for transmission range sensor A. Selector positions cannot be mapped reliably until adaptation completes.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: easy
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.
- Adaptation lost after battery disconnect or TCM resetCommon
- Sensor replaced without learn procedurePossible
Parts involved
- Transmission Range Sensor A
- TCM
P280A 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.