Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
Your car's battery system has a part that helps control the flow of electricity. This error means there's a problem with that part, and it can't turn off the electricity flow properly.
This code indicates an issue with the battery positive contactor, which is responsible for disconnecting the high-voltage battery when needed.
The P1A57 code is triggered when the vehicle's control module detects a malfunction in the shutdown path of the hybrid or electric vehicle's battery positive contactor. This contactor is a switch that connects and disconnects the high-voltage battery to the vehicle's electrical system. If it fails to operate correctly, it can cause safety and performance issues.
• Check Engine Light is on
• Vehicle may not start
• Reduced power or performance
• Faulty battery positive contactor
• Wiring issues or poor connections
• Faulty control module
Contactor: A switch used to control the flow of electricity.
Control Module: A computer in the vehicle that manages various systems.
• Use an OBD-II scanner to confirm the code.
• Inspect the battery positive contactor and associated wiring.
• Test the control module for faults.
• Replace the battery positive contactor if faulty.
• Repair or replace any damaged wiring or connections.
• Replace the control module if necessary.
• OBD-II scanner
• Multimeter
• Wrench set
$200 - $800
Moderate
• Chevrolet Volt
• Toyota Prius
• Nissan Leaf
• Regularly inspect electrical connections.
• Perform scheduled maintenance on the hybrid/EV system.
• Avoid overloading the electrical system.
Electrical System Issue
• Do not attempt to drive the vehicle if it won't start.
• Consult a professional mechanic for diagnosis and repair.
Repairs may be covered under the vehicle's hybrid/EV system warranty.
This code has been more prevalent with the increasing use of hybrid and electric vehicles, highlighting the importance of maintaining high-voltage systems.
High – This issue can prevent the vehicle from starting or operating safely.
Driving with this issue can be unsafe. Always follow manufacturer guidelines and consult a professional for repairs.
• Vehicle in 'Ready' mode
• Battery fully charged
The battery positive contactor is typically located near the high-voltage battery pack.
Q: Can I drive my car with a P1A57 code?
A: It's not recommended, as this issue can affect the vehicle's ability to start or run safely.
Q: How do I reset the P1A57 code?
A: After repairs, use an OBD-II scanner to clear the code. However, ensure the issue is fixed first.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.