Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC B1973: High Power Control Fault: Notes
Battery guard relay supplies power to modules during controlled power usage. For 15 minutes after ignition is turned to LOCK position and BCM is awake, battery guard relay output coil is grounded. After 15 minutes, low power driver output is turned on.
DTC B1973 will set when BCM detects a short to battery in battery guard relay output circuit. When DTC B1973 is set, BCM will turn low power control output off if ignition is in LOCK position. DTC B1973 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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