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EV Charger Error

SLAC Protocol Error

Updated March 2026

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This is general guidance based on the ChargeX MREC standard. Actual charger behavior varies by manufacturer and firmware version. Always follow on-screen instructions and contact the charging network if you are unsure.

Warning

The Signal Level Attenuation Characterization (SLAC) process failed. SLAC is the first step in CCS communication where the charger and vehicle establish a data link through the charging cable. If this fails, no further communication is possible.

What to do

  1. Unplug and reconnect firmly. A poor physical connection can cause SLAC failure
  2. Try a different CCS connector
  3. Try a different charger entirely
  4. This is typically a charger or cable issue, not your vehicle

Who's responsible?

  • This is likely a charger hardware issue

Technical details

Error code
SLACError
Category
Communication
Classification
maintenance
Source
ChargeX MREC Standard (2023)

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