P0826
Up and Down Shift Switch Circuit
The TCM detects a fault in the combined up/down shift switch circuit, where both switch states are simultaneously active or both inactive when activity is expected.
- 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.
- Switch internal shortCommon
- Wiring shorted between channelsPossible
Parts involved
- Shift Switch Assembly
- Wiring Harness
P0826 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.