OBD-II code · Powertrain (generic)
P0703 Brake Switch B Circuit
A general circuit fault on the secondary brake switch B - typically used as redundant input for safety-critical functions like cruise control cancellation and shift-interlock.
Is it safe to drive with P0703?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in switch or wiring
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
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.2 h
- Emissions test
- Usually unaffected
- Parts involved
- Brake Switch B
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.