Fault Finding & Diagnostics
Professional root cause analysis, not just fault code reading. We understand what the ECU is actually seeing and why it's reporting what it is.
Code Reader vs Professional Diagnostics
A cheap OBD reader
Plugs in, pulls a fault code like "P0101 — Mass Airflow Sensor out of range", tells you to clear it. Repeat the fault three times and go back to the reader.
Useful for basic information, but doesn't explain why the code is being triggered.
Professional diagnostics
We connect via Alientech K-Suite — full ECU read access. We look at live data streams in real time: what the ECU is actually seeing from every sensor, how it's interpreting that data, what it's commanding the engine to do in response.
We compare those values against expected parameters. When something doesn't match, we know exactly where the chain breaks.
Understanding What's Actually Wrong
Live data streams show us sensor readings as the ECU sees them. We can watch MAP pressure, MAF airflow, coolant temperature, fuel rail pressure, turbo boost, O2 sensor voltages — everything the engine is experiencing, moment to moment.
Freeze frame data captures the exact conditions when a fault occurs — what was the coolant temperature, what was the engine load, what fuel trim was being applied — all frozen at the moment the fault code was generated.
We look for patterns. A persistent "limp mode" often points to turbo actuator pressure, MAF sensor drift, or DPF saturation — not always obvious from the code alone. A warning light that keeps returning means the underlying fault hasn't been fixed, only the code cleared.
We don't clear codes without understanding them. If we can't fix it on that visit, we give you a written summary of what we found, what we believe the cause is, and what the repair options are.
What We Commonly Find
Limp Mode
Engine goes into restricted power mode. Usually a turbo actuator fault (boost control losing pressure), MAF sensor drifting out of range, or DPF backpressure reading high. Each points to different repairs, but all are findable via live data.
Persistent Warning Lights
Cleared once, comes back within 50 miles. The code is a symptom, not the cause. We investigate the underlying sensor chain or system fault that's triggering the code repeatedly.
Poor Fuel Economy With No Codes
Engine's running but consuming fuel badly — often EGR stuck open, fuel trim way off, or fuelling control oscillating. No fault code, just bad efficiency. Live data shows us immediately.
Misfires
Rough idle, stuttering under load. Could be injectors, coil packs, spark plug quality, fuel pressure, timing control, or a combination. We check each component's contribution via real-time data.
What We Can Diagnose
Engine Management
Fault codes, sensor drift, fuel system control, ignition timing faults — all common fuel system ECU issues.
Turbo & Boost
Actuator valve faults, boost control loss, wastegate issues, boost pressure sensor problems.
Emissions Systems
DPF blockage vs software faults, EGR valve sticking, AdBlue system faults, NOx sensors.
Transmission
On supported vehicles — shift fault codes, torque converter issues, TCM communication problems.
Fuel Systems
Fuel pressure faults, injector function, fuel trim issues, common rail pressure problems (diesel).
Sensors
MAF sensor, lambda sensor, boost pressure, coolant temperature, air temperature sensors — all testable via live data.
Fully Mobile Diagnostics
We don't need to tow your car away. We're fully mobile — we come to you, with the K-Suite kit and all the diagnostic tools we need. We need the vehicle running and the OBD port accessible.
Typical diagnostic session is 1–2 hours, depending on the fault. Some issues are quick to isolate; others require road testing or multiple live data captures under different conditions to confirm what's happening.
If we identify a repair that's beyond our scope — say, a faulty transmission control module that needs replacement — we'll tell you clearly and provide a summary so you know exactly what to get fixed and where.
FAQ
Yes. That's exactly the kind of situation we deal with. A code comes back because the underlying fault hasn't been fixed — the garage just cleared the symptom. We look for root causes: sensor degradation, wiring issues, component faults. We'll find why the code is being triggered and give you repair options.
No — we're fully mobile. We come to you with all the equipment needed. The car needs to be running and the OBD port accessible, but we work on-site. No recovery trucks, no drop-off hassle.
Usually 1–2 hours depending on the fault. Some are quick to isolate with live data; others require road testing or multiple capture sessions to see the fault behaviour repeat. Once we understand it, we give you a clear written summary.
We give you a clear written summary of what we found, what we believe the cause is, and what the repair options are — whether that's something we can do or something for a specialist mechanic. You'll have a complete understanding of the fault and your options.
Stuck With A Fault?
Get professional diagnostics to understand what's actually wrong.