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
Controlled power relay supplies power to modules during controlled power usage. For 15 minutes after ignition is turned to LOCK position and PZM is awake, high power control output is grounded. After 15 minutes, low power control output is turned on. Low power control output will supply 2 amps of current for up to 72 hours. If PZM detects more than 2 amps of current is needed, PZM will wake-up and turn on high power control output.
DTC B1973 will set when high power control voltage does not match that of feedback voltage for 2 seconds. When DTC B1973 is set, PZM will turn low power control output off if ignition is in LOCK, OFF or ACC position. DTC B1973 will clear when PZM does not detect malfunction for one monitoring cycle.
NO RELATED
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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.