Diagnostics

Standard Diagnosis

Warning lights · Limp mode · AdBlue & DPF · Mercedes cars & vans

From £120+ VAT · Fixed price · We come to you

Dashboard lit up? We come to you with Mercedes dealer-level tooling, find the root cause, and leave you with a clear written fix plan, not guesswork.

From real visits

Picoscope and multimeter set up on a Mercedes for live signal capture during diagnosis — Picoscope + multimeter on a Mercedes, we measure live signals, not guess at codes.

Smoke machine leak testing the intake on a Mercedes diesel during diagnosis — Smoke testing the intake, visible proof of every boost leak.

Multimeter probes inserted to measure exhaust pulse pressure on a Mercedes Sprinter — Exhaust pulse pressure check, finds restricted DPFs a code reader misses.

Common faults we fix

Warning light AdBlue / DPF Limp mode Electrical Xentry / coding

How it works

Get in touch

Postcode, vehicle & symptoms, fixed price confirmed.

Book a slot

We arrive with full diagnostic kit.

On-site diagnosis

Full scan & live data (up to 60 mins).

Written fix plan

Root cause & next steps, plain English.

Get in touch

Tell us your postcode, vehicle, and symptoms. We confirm your zone and fixed price.

Confirm your slot

Pick a date and time that works for you. We arrive at your location with full diagnostic kit.

On-site diagnosis

Deep scan across all modules, live data checks, guided tests, sensor plausibility, and actuations.

Written fix plan

You get a clear outcome: fault codes, root cause, and recommended next steps. Plain English, no jargon.

Real faults we've found

Photos from real Mercedes diagnostic visits, tap any image to see the fault.

What we diagnose

One service, one price, all fault types below.

Engine management light, ABS, ESP, glow plug, battery, and any other dashboard warning. We scan every module - not just the engine - to find the root cause, not just clear codes.

Multimeter probing a sensor circuit on a Mercedes engine bay during live testing — Live circuit testing on the actual sensor, not just a code read.

Warning Lights & Fault Codes

Engine management light, ABS, ESP, glow plug, battery, and any other dashboard warning. We scan every module - not just the engine - to find the root cause, not just clear codes.

Live circuit testing on the actual sensor, not just a code read.

Emissions, AdBlue & DPF

AdBlue countdown, SCR/NOx sensor faults, DPF soot load and regen issues, EGR problems, and dosing unit failures. Live data testing, not just fault code reads - we identify whether you need a sensor, a regen, or a deeper repair.

Oil-contaminated EGR pipe, found via emissions diagnosis on a Mercedes diesel.

Limp Mode & Derate

Turbo boost faults, fuel rail pressure issues, injector drift, EGR valve failures, and wiring faults that cause derate. Systematic testing to isolate the root cause - especially on Sprinters (W906/W907/W910).

Hairline intercooler crack, root cause of boost loss and a limp-mode derate.

Electrical & Wiring Faults

Intermittent faults, parasitic battery drain, CAN network communication issues, connector corrosion, and random warning lights. We use oscilloscope and live data capture to replicate and trace faults.

Corroded multi-pin connector, root cause of an intermittent CAN-bus fault.

Mercedes Xentry & OEM Coding

Dealer-level Xentry access for SCN coding, variant coding, module adaptations, DAS guided tests, and initialisation. Used as part of Standard Diagnosis when OEM-level access is required.

Dealer-level Xentry on site, guided tests, coding, and module access when OEM-level work is needed.

What's Included

Full-system scan (all modules, not just engine)
Freeze frame and fault code analysis
Live data checks and sensor plausibility
Guided tests and actuations where applicable
Mercedes Xentry dealer-level access when needed
Written findings and root cause analysis
Recommended next steps and quote for follow-on work
Up to 60 minutes on-site time

What Your Written Outcome Looks Like

Every Standard Diagnosis ends with a documented written outcome. Below is a glimpse from one real visit. See the full walkthrough for how plain English, ruled-out causes, live data, and next steps fit together.

See the Full Report Example

Pricing

Zone A

0 to 25 mins

£120+ VAT

Zone B

25 to 45 mins

£135+ VAT

Zone C

45 to 60 mins

£150+ VAT

Includes travel and up to 60 mins on-site. Extra time £85/hr + VAT in 15-min blocks.

Zone	Drive time	Price
Zone A	0-25 mins	£120+ VAT
Zone B	25-45 mins	£135+ VAT
Zone C	45-60 mins	£150+ VAT

Includes travel and up to 60 mins on-site. If additional diagnostic time is needed, it's billed at £85/hour + VAT in 15-minute blocks.

Fleet & Commercial Customers

We work with fleet operators, hire companies, and depot managers across Kent and South East London. If you have multiple vehicles needing diagnostic attention, we can arrange bulk visits with priority scheduling. Common fleet scenarios include proactive health checks, fault sweeps, and DPF/AdBlue status reviews across your fleet.

Discuss fleet requirements on WhatsApp

When Workshop Referral May Be Needed

Work requiring ramp or major underbody access
Heavy drivetrain jobs that can't be done safely mobile
Faults requiring manufacturer-specific online access (documented for referral)

Frequently Asked Questions

We'll tell you honestly. If a fault is intermittent or needs specialist equipment we don't carry mobile, we'll document what we've checked and refer you to an appropriate workshop with our findings. You still get a written outcome - no dead ends.

Ideally yes - we like to discuss symptoms with you and may need the keys for guided tests. If you can't be there, we can work with someone you authorise (e.g. at a depot). Just let us know when booking.

We'll quote you for the parts and labour before any work begins. We use genuine Mercedes parts. Follow-on labour after the included 60 minutes is £85/hour + VAT in 15-minute increments.

The diagnostic visit is up to 60 minutes on-site. If we need additional time to investigate a complex fault, we'll discuss it with you first. Extra diagnostic time is billed at £85/hour + VAT in 15-minute blocks.

Yes. Standard Diagnosis covers Mercedes cars and vans, plus other makes. Our specialist focus is Mercedes commercial vehicles, but the diagnostic process and tooling works across the range.

Standard Diagnosis is our core service for any vehicle with a fault or warning light - 24-hour notice, thorough investigation, written fix plan. VOR Diagnosis is for commercial vehicles that are off the road and need a fast back-on-road decision, with zero minimum notice and priority dispatch.

Yes - emissions, AdBlue, DPF, SCR, NOx, and EGR faults are all covered under Standard Diagnosis. We test with live data, not just fault code reads, so you get a proper root cause and clear next steps.

Absolutely. We work with fleet operators, hire companies, and depot managers regularly. If you have multiple vehicles, we can arrange bulk diagnostic visits. Get in touch via WhatsApp or call to discuss.