P0B33High Voltage Service Disconnect Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- The high-voltage service disconnect is the removable plug, usually fused, that splits the traction battery for safe servicing. A low-voltage detection loop runs through the plug, and the battery controller reads it to know whether the plug is seated; patents from Ford and Lear describe this loop, which opens before the main contacts part. P0B33 is the general circuit code for this detection input. No manufacturer documents P0B33 publicly. CARB requires such hybrid components to be monitored like any input. Performance, low, high and open have their own codes, P0B34 to P0B37; the separate high-voltage interlock loop uses P0A0A ff. Expect contactors to stay open: no ready mode, no charging.
- What you may notice
- Vehicle does not enter ready mode or will not start
- High-voltage system warning and MIL on
- Charging not possible
- Likely causes
- LikelyService disconnect plug not fully seated or locked after service
- PossibleChafed, open or shorted detection loop wiring between plug base and battery controller
- PossibleCorroded or spread terminals in the plug or its base
- RareBattery controller input fault
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €80 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.