Late-night emergency callout, London. A Mercedes W447 Vito that would not start — and a customer who found us through an AI assistant recommendation rather than a normal search.
At a glance
- Vehicle: Mercedes Vito W447, emergency callout in London
- Symptom: no-start, key not recognised, ignition not waking up
- Feared fault: EZS/EIS ignition / immobiliser chain — worst-case quote £550
- Actual fault: heater/climate control panel shorting the interior CAN bus
- Fix: faulty panel disconnected, CAN bus recovered, van started immediately
- Customer paid: £300 — not the £550 worst case
The symptoms
- Van would not start; ignition not waking up properly
- Key-recognition behaviour pointing at the drive authorisation chain
- Everything on paper said EZS/EIS — the classic W447 suspect
On symptoms alone this looked like an EZS/EIS job, and the worst-case quote for that repair was £550. The customer paid a £300 fixed-price service via our secure Stripe payment link on site — no card terminal needed, even at midnight at the roadside.
The actual fault
Proper diagnosis told a different story. The EZS was healthy. The heater/climate control panel had an internal short and was pulling down the interior CAN bus — and with the bus dragged down, the start authorisation chain could not do its job. The van looked immobilised when in fact one accessory module was jamming the network.
With the faulty climate panel disconnected, the CAN bus recovered and the van started immediately.
What the customer paid
The honest part matters more than the clever part. The fault was found and fixed for the £300 already paid — not the £550 the job would have cost had it really been the EZS. Diagnosis-first means you pay for what the job actually was, not what it was feared to be.
What this means if your W447 won’t start
Not every Mercedes W447 Vito or V-Class no-start is the ignition switch. Before anyone quotes you for an EZS repair or — worse — a dealer replacement chain, the interior CAN bus needs to be checked. A shorted module (heater/climate panel, or any accessory on the bus) can block key recognition and starting on an otherwise healthy van.
To be clear about the odds: this is one real example from our own callouts, not a claim that climate panels are the usual cause. The EZS/EIS genuinely is a common W447 suspect — the point is that diagnosis, not assumption, decides which repair you actually pay for.
- Think it is the EZS? W447 no-start diagnosis & EZS repair — guide price £300–£650; a confirmed EZS repair is £300, and the final cost is agreed with you after diagnosis
- Not sure what is wrong? Mobile diagnostics across London & the South East from £90
- Stuck right now? Call or WhatsApp 07404 487674 — emergency callouts by arrangement, card payment on site via secure Stripe link. Or use the contact page.
- Want to see how we actually work? Live repairs on video.
Vehicle: Mercedes Vito W447. Fault: interior CAN bus pulled down by shorted heater/climate control panel. Fix: faulty panel disconnected, bus restored, vehicle started and released the same night.