MERCEDES · DTC LOOKUP
EIS not reading key — Mercedes EIS fails to authenticate inserted key
Mercedes diagnostic code. Below: what it means, common causes, symptoms, and the exact bench-programming fix path.
Common causes
- •EIS firmware degradation (most common pre-2014)
- •Key chip damaged or broken
- •EIS coil fault
- •All keys lost
Symptoms you'll see
- •Cranks but won't start
- •EIS LED indicator behaves unusually
- •Intermittent — sometimes works
- •No "ESL Released" prompt before crank
The fix path
If keys are physically OK, EIS cloning ($250) onto a donor preserves your keys. If all keys lost, EIS Key Replacement ($150) programs a fresh key directly.
AML services that fix this
Mail in the affected module, we bench-program, ship back next business day. Flat pricing, return shipping included.
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Related diagnostic codes
U0001High Speed CAN Communication Bus ErrorSteering lock faultMercedes Electronic Steering Lock (ELV) failureCrank-no-startEngine cranks normally but won't startAll keys lostNo working key for a European vehicleP164BEngine Stop Detected — Immobilizer ActivatedMercedes W220 EIS failureW220 S-Class EIS authentication failureNot sure which service applies?
Text us your year/make/model + which scanner caught the code — we'll tell you exactly which module to ship and which service to pick.