The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2018 S560 Multiple Warning Lights (ABS/ESP) and Battery Drain

0

Mike T. · rep 0 · May 25, 3:04 AM · 1 replies · solved · Question

Vehicle: 2018 Mercedes-Benz S560 Sedan

Good morning everyone,

I'm having a very frustrating issue with my 2018 Mercedes-Benz S560 Sedan. Recently, I've noticed multiple warning lights appearing on the dashboard: ABS, ESP, and sometimes even the SRS (airbag) light. They don't always come on together, but it's happening more frequently.

Compounding this, my battery seems to be draining overnight. If I don't drive it for a day, the battery is often too low to start the car. I've had the battery tested, and it's supposedly good, though it's the original one. I've also checked for obvious lights left on, but can't find anything.

Could these issues be related? What are common causes for multiple warning lights and parasitic battery drain on an S-Class? Any insights would be helpful.

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 25, 3:04 AM

0

ClearTheCode admin answer:

Multiple warning lights (ABS, ESP, SRS) coupled with a parasitic battery drain on your 2018 Mercedes-Benz S560 suggest a complex electrical issue. These systems are highly interconnected, and a fault in one module or a power supply problem can cascade into various warnings and excessive battery draw.

Here are potential causes and diagnostic steps:

  1. Failing Wheel Speed Sensors: A common cause for ABS and ESP lights. If one or more wheel speed sensors are faulty, the system loses crucial data, triggering warnings. While this usually doesn't cause a battery drain directly, it's a primary suspect for the lights.
  2. ABS/ESP Control Module: A failing ABS/ESP control unit itself can cause these lights. In some cases, a faulty module can stay 'awake' or draw excessive power, contributing to a battery drain.
  3. Parasitic Draw: This is the most likely cause for your battery drain. It means a component or module is drawing power even when the car is off. Common culprits include:
    • Faulty Control Modules: Any module (e.g., infotainment, telematics, door control, seat control) that isn't properly entering sleep mode.
    • Aftermarket Accessories: Incorrectly installed aftermarket electronics.
    • Short Circuits: Less common, but a short could cause a continuous draw.
  4. Aging Battery: Even if it tested 'good,' an original battery from 2018 might be at the end of its life, especially with the S-Class's high electrical demands. A weak battery can cause modules to behave erratically and trigger false warnings.
  5. Alternator Issues: While usually causing a 'Battery' light, an intermittently failing alternator might not fully charge the battery, leading to low voltage and subsequent issues.

When to see a shop:

  • Urgency: This issue needs prompt attention. Driving with compromised ABS/ESP can be a safety hazard, and a dead battery is always inconvenient.
  • Professional Diagnosis: Due to the complexity of the S-Class's electrical systems, a Mercedes-Benz specialist is essential. They can:
    • Perform a comprehensive diagnostic scan using XENTRY/DAS to read all fault codes from every module, including 'C' (chassis) and 'B' (body) codes that generic scanners miss.
    • Conduct a parasitic draw test to identify which circuit or module is drawing excessive current.
    • Test the battery under load and check the alternator's charging output.
    • Inspect wiring harnesses for any visible damage or corrosion.

Resolving the parasitic draw is key to preventing future battery issues and may even resolve some of the warning lights if they are voltage-related.

Menu

Help & account