What u1 Means
u1 on a Bosch French door refrigerator flags the V-sensor, one of the compartment temperature sensors the control uses alongside the main fresh food and freezer probes. The repair manual records the same two states as for the other probes, a disconnection or a short, and the same approach: unplug connector CN14 at the main board, measure across the terminals, and replace the sensor if it reads open or shorted.
Common Causes of u1
- V-sensor failed open or shorted
- Connector CN14 not seated at the main board
- Harness damage between the sensor and the board
🔧 One Safe Check You Can Try
Note carefully which compartments are actually running at the wrong temperature and for how long. A sensor code with normal temperatures everywhere is a different conversation from one where a whole section has drifted.
⚠ Why You Shouldn't Go Further Than That
- Several sensors land on the same board connector, so a single loose plug can produce more than one code and be misread as multiple failures.
- Main board access is behind the cabinet, which means moving a heavy appliance with a water line still attached on plumbed models.
- Freezer-grade plastics around sensor mountings crack when levered cold, and a cracked liner is not a repairable part.
- Sensor resistance has to be compared against Bosch's published figures for this platform, not judged as merely present or absent.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.