Mercedes-Benz P0562

System voltage low on Mercedes — alternator failure and dual-battery system issues on S/E/GL with second battery.

Mercedes-Benz P0562 — System voltage low on Mercedes — alternator failure and dual-battery system issues on S/E/GL with second battery. Typical UK independent garage cost: £180–£720.

What actually causes P0562 on a Mercedes-Benz

Many modern Mercedes (S, E, GL, ML) run a dual-battery system — main starter battery plus a small auxiliary battery in the boot/wheel arch. The auxiliary battery fails first (around 4–6 years) and triggers P0562 even when the main starter battery is fine. On Sprinters the alternator brushes wear out around 120k miles. On C/E-Class W204/W212 a corroded battery sensor on the negative terminal causes phantom P0562.

Mercedes-Benz engines that log P0562

• C-Class W204/W205 (C220 CDI, C200 CGI)
• E-Class W212/W213 (E220 CDI, E250 CGI)
• Sprinter (411/411 CDI/313 CDI)
• ML/GL W164/X166 (ML350, GL350)

How we diagnose P0562 on a Mercedes-Benz

1. Xentry / Star — read main and aux battery voltages
2. Inspect battery sensor on main battery negative terminal
3. Test both batteries separately under load
4. Inspect alternator output and brushes (Sprinter especially)
5. Code/register new battery via Xentry

The common misdiagnosis to avoid

Always check for an auxiliary battery on E/S/GL before fitting a main battery — fitting one and missing the failed aux battery means P0562 returns in days and customer's furious.

Mercedes-Benz P0562 repair cost in the UK

Expect £180–£720 including parts and labour at an independent garage. Main-dealer quotes on Mercedes-Benz are usually higher for the same job, and the spread exists because the cheap cause and the expensive cause throw the same code — pay for the diagnosis before you pay for parts.

Bob's workshop tip

On Sprinter 313/315 CDI vans showing P0562 with high mileage, consider going straight to a remanufactured alternator with new brushes (£280–£350 fitted) — it's the fastest path to a fix and brush wear is the cause 80% of the time at 120k+.

Codes usually seen alongside P0562 on Mercedes-Benz

• P0563
• P0620
• P0625

Symptoms drivers report with P0562

• Battery warning light flickers intermittently, especially at idle with electrical load on
• Dashboard dims when indicators are on or wipers run
• Car fails to start cold after sitting for 2–3 days
• Stop-start system disables itself with a 'battery saver active' message
• Voltmeter reads below 13.2V with engine running

Repairs that clear P0562

• Load-test battery
• Alternator output test
• Clean and torque earths

For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0562 guide.