High Voltage Service Disconnect Circuit High
The P0B36 code indicates that the high voltage service disconnect circuit voltage is higher than expected. This circuit is part of the high voltage interlock loop, which ensures safe disconnection of high voltage components during service. A high voltage condition may be caused by a faulty service disconnect switch, wiring issues, or a malfunction in the battery management system. This can prevent the vehicle from operating or charging properly.
01. Most Common Causes
- Faulty high voltage service disconnect switch
- Short to voltage in the service disconnect circuit wiring
- Malfunctioning battery management system (BMS) module
- Corroded or damaged connectors in the high voltage interlock loop
02. Symptoms You Will Notice
- Vehicle may not start or go into ready mode
- Warning lights on dashboard (e.g., check hybrid system)
- Reduced or no electric power assist
- Inability to charge the high voltage battery
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Visually inspect the high voltage service disconnect switch and its wiring for damage or corrosion.
Step 3: Measure voltage at the service disconnect circuit to confirm high voltage condition.
Step 4: Check for shorts to voltage in the wiring harness using a multimeter.
Step 5: Test the battery management system (BMS) module for proper operation.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe to drive. The high voltage system may not be properly isolated, posing a risk of electric shock or component damage. The vehicle should be towed to a qualified repair facility.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on the cause. Replacing a service disconnect switch may cost $150-$250, while BMS module replacement can be $300-$400 or more.