High Voltage Service Disconnect Open
The P0B37 code indicates that the high voltage service disconnect switch in a hybrid or electric vehicle is in the open position. This switch is a safety device that isolates the high voltage battery pack from the rest of the vehicle's electrical system during maintenance. When open, the vehicle's high voltage system is deactivated, preventing the electric motor from operating and the battery from charging. This can be caused by a manual disconnect, a faulty switch, or a wiring issue.
1. Symptoms You Will Notice
- Vehicle will not start or move
- High voltage system warning light on dashboard
- Electric motor inoperative
2. Most Common Causes
- Service disconnect switch manually left open
- Faulty service disconnect switch
- Wiring or connector issue in the high voltage interlock loop
3. Step-by-Step Diagnosis
Step 1: Check if the high voltage service disconnect switch is fully closed and latched.
Step 2: Inspect the switch and its wiring for damage, corrosion, or loose connections.
Step 3: Use a multimeter to test continuity through the switch and the interlock circuit.
Step 4: If the switch is faulty, replace it and clear the code.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, the vehicle will not operate because the high voltage system is disconnected. It is not safe to drive as the electric motor and battery are isolated.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150, depending on whether the switch needs replacement and labor rates.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.