Many Mercedes models made from the early 2000s to the mid-2010s use an EIS (electronic ignition switch). Instead of a metal barrel, the key slots into an electronic unit that checks the key and tells the car it may start. When the EIS fails, a perfectly good key suddenly does nothing.
Signs of an EIS fault
- The key goes in but won't turn
- No lights on the dashboard when the key is inserted
- The key turns, but the car won't start, sometimes only now and then
- The key gets stuck in the EIS or won't come out
- The car started fine yesterday, and today nothing
These faults are common on models such as the C-Class, E-Class, CLK, ML, Sprinter and Vito. On some of them, the ESL (electronic steering lock) fails at the same time or causes the same symptoms, so we check both.
How we fix it
- We diagnose the fault with professional equipment: EIS, ESL or the key itself.
- We repair or replace the EIS and programme it to your car.
- We check the key and the steering lock, so the car starts and the wheel releases every time.
All of this happens where the car is parked: no tow truck and no waiting days for a dealer.
EIS or ESL?
Symptom | More likely |
|---|---|
Key goes in, no dash lights, key won't turn | EIS or ESL |
Dash lights come on, steering stays locked | ESL |
Key turns, car cranks but cuts out | Key or immobiliser |
We see both on Mercedes: see our ESL repair page for two real Mercedes jobs.
Where we work
South London and Surrey, 24/7: Croydon, Sutton, Kingston, Wimbledon, Streatham, Lewisham, Epsom, Redhill and Reigate, and the areas around them (SE, SM, CR, SW, KT and RH postcodes).