U0001 — High Speed CAN Communication Bus Error
Mercedes diagnostic code. Below: what it means, common causes, symptoms, and the exact bench-programming fix path.
Common causes
- •Failing EIS / EZS module (W204/W212/W221 chassis)
- •CAN-H or CAN-L wire fault
- •Failed gateway module
- •ECU connector corrosion
Symptoms you'll see
- •Multiple modules report communication errors
- •EIS warning intermittent
- •Engine doesn't start
- •Cluster goes blank periodically
The fix path
Verify CAN-bus integrity first (wire continuity, gateway). If wiring checks out, suspect the EIS — Mercedes EIS Cloning ($250) or Key Replacement via EIS ($150) is the bench fix.
AML services that fix this
Mail in the affected module, we bench-program, typically ship back next business day. Flat pricing, flat-rate return shipping at checkout.
Mercedes EIS Cloning (Pre-2014)
$250Failed Mercedes EIS leaving you with a car that won't start? We clone it to a replacement EIS — your existing keys keep working, no re-keying the car.
Service detailsMercedes Key Replacement via EIS
$150Lost your only Mercedes key? Ship us your EIS — we program a fresh working key directly on the bench.
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Related diagnostic codes
Steering lock faultMercedes Electronic Steering Lock (ELV) failureEIS not reading keyMercedes EIS fails to authenticate inserted keyCrank-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.