Warning light on? Call us today
01604 715 515
Warning light on your dashboard? Strange noise or fault you can't identify? We use dealer-grade diagnostic equipment to read fault codes and get to the root cause — then we fix it. All makes and models, Bunting Road NN2.
Modern cars are complex — dozens of sensors, multiple ECUs, and thousands of possible fault codes. When a warning light comes on, or something feels wrong but you can't pinpoint it, you need a garage with the right equipment and the experience to interpret what it's telling you.
At Alderley Autos on Bunting Road, Northampton, we use dealer-grade diagnostic equipment to connect directly to your car's onboard systems. We read fault codes, view live sensor data, carry out actuator tests and — crucially — we can carry out the repair in the same visit. We're not just a code reader. We're a full repair garage that uses diagnostics as a tool to fix your car properly.
We're also known for technical fault finding — the more difficult skill of diagnosing faults that don't always trigger a warning light, faults that return after being cleared, or problems that other garages have failed to identify. Other garages and car dealers across the UK call us for advice on difficult Vauxhall and technical faults. That expertise is available to you here in Northampton.
What to do when a light comes on. Colour matters — here's what each means.
Stop driving as soon as it is safe. A flashing engine light means an active misfire causing immediate catalyst damage. Red oil, temperature or battery lights mean stop now to prevent serious engine damage.
STOP IMMEDIATELYThe car can usually be driven carefully but should be checked soon. The fault has been detected and stored. Do not ignore it — amber lights that are left can become more serious or expensive faults.
Check SoonInformational only — headlights on, high beam active, indicators. These are not fault warnings. However, if an unfamiliar blue or green light appears that won't go out, call us and we'll advise.
InformationalThe most common warning light. Could be anything from a loose fuel cap to a serious sensor fault. Always needs a diagnostic scan to identify the specific code.
Check SoonAnti-lock braking system fault. Normal brakes still work but ABS will not operate in emergency stops. Typically a wheel speed sensor or ABS pump fault.
Check SoonFault with the supplemental restraint system. Your airbag may not deploy in a collision. Usually a faulty sensor or connector. Do not ignore.
Check SoonLow oil pressure — potential engine damage imminent. Check oil level immediately. If level is fine and light stays on, stop and call us.
Stop / UrgentEngine overheating. Stop immediately, do not remove the coolant cap. Could be a blown head gasket, failed thermostat or coolant leak.
Stop / UrgentDiesel Particulate Filter is blocked. On motorway-capable cars a regeneration run at 60mph+ may clear it. If not, professional cleaning or replacement is needed.
Check SoonCharging system fault — alternator, serpentine belt or battery. The car may only have minutes of running time left. Do not turn the engine off.
Stop / UrgentElectronic stability system fault. Usually triggered on slippery surfaces, but if it stays on while driving normally a sensor fault is likely.
Check SoonNot sure what your warning light means? Call us and describe it — we'll advise straightaway.
Call 01604 715 515Our equipment covers every major vehicle system. We read the fault, then we fix it.
Full engine ECU diagnostics covering fuel trim, ignition timing, sensor readings, misfire data and ECU communication. We identify the root cause, not just clear the code.
ABS and stability control systems diagnosed including individual wheel speed sensors, hydraulic pump faults and control module issues. We repair, not just diagnose.
Airbag warning lights diagnosed and repaired. Common causes include faulty impact sensors, clock spring faults, seat belt pretensioner issues or corroded connectors.
DPF blockage, catalytic converter faults, AdBlue system issues and emission-related fault codes. We diagnose the cause of failure before recommending forced regeneration or replacement.
Body Control Module (BCM), central locking, electric windows, instrument cluster faults, lighting circuits and CAN bus communication errors diagnosed and repaired.
Automatic gearbox fault codes, clutch position sensor faults, torque converter issues and DSG / dual-clutch transmission diagnostics. Live data monitored during road test where needed.
Simply reading a fault code tells you a system has reported a problem. Understanding why it happened, and what caused it, requires more. Here's what our equipment enables us to do:
We read all stored and pending fault codes from every ECU on the vehicle, identify what they mean in plain English, and clear them once the repair is complete.
We monitor real-time sensor data — fuel trims, injector pulse, sensor voltages, temperatures, RPM — to identify components that are reading incorrectly even when no fault code is present.
We can command individual components to activate — fuel injectors, EGR valves, cooling fans, solenoids — to confirm they are responding correctly to the ECU's signals.
Service interval resets, throttle body adaptations, steering angle sensor calibration, brake calliper retraction for electronic handbrakes, and DPF regeneration cycles.
Module coding and parameter resets following component replacement, including key coding and immobiliser programming on many vehicle makes.
There is a significant difference between reading a fault code and actually diagnosing a car. A fault code tells you which system has reported an issue. It doesn't always tell you what caused it, especially with intermittent faults, multiple codes, or symptoms that don't generate a code at all.
Technical fault finding is the deeper skill — using live data, wiring diagrams, component testing and experience to trace a fault to its true root cause. This is what sets experienced independent mechanics apart from garages that simply plug in a reader and replace parts hoping for the best.
At Alderley Autos we are well known for this capability, particularly on Vauxhall vehicles. Other garages and dealers across the UK regularly contact us for guidance on difficult faults they cannot resolve. If your car has been to another garage and the problem keeps coming back, bring it to us.
Call 01604 715 515"My experience with Alderley and Gary was nothing short of exceptional. His professionalism and thoroughness were second to none. He diagnosed a fault two other garages had missed. Can confidently recommend him to anyone."
Describe what your car is doing — warning lights, symptoms, when it started. We'll give you an idea of what it could be and get you booked in quickly.
We connect our equipment to your vehicle, read all fault codes from every ECU, view live sensor data, and where needed carry out a road test to reproduce the fault.
We explain what we found in plain English — no jargon. You get a fixed quote for the repair before any work begins. Nothing is done without your approval.
We carry out the repair in-house, clear the fault codes, and verify with a post-repair scan that the fault has gone. No sending you elsewhere.
Customers visit us from across Northampton and the NN postcode for diagnostics — including faults other garages couldn't identify.
103 Bunting Road, Northampton NN2 6EE | 01604 715 515