P0562
CAUTION
System voltage low
The truck's control module (ECU) reports a fault on: System voltage low.
P0562 means a truck control module (ECU) flagged a fault on system voltage low, part of the Electrical / J1939 system on heavy-duty diesel trucks. DERATE rates it CAUTION: you can keep driving carefully, but get it checked soon. Part usually replaced: Alternator, $300–$1,200 (aftermarket to dealer) plus 1–2.5 h labor.
Electrical / J1939
Can I keep driving?
Yes, carefully. It does not usually cut power, but get it checked soon.
Part usually replaced
Alternator
$300–$1,200 (aftermarket to dealer)
Labor: 1–2.5 h
USD, part only. Labor is billed at the shop's hourly rate.
Data: DERATE verified base, updated October 2026
Related codes
Read it off your own dash
Take one photo and DERATE tells you whether you can keep driving.
Ask DERATE
DERATE assists. It does not replace inspection by a qualified technician.