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KITH Cars Garage — Hackbridge, South London

Engine Diagnostics in Hackbridge, South London

Engine diagnostics at KITH Cars Garage in Hackbridge covers all warning lights, fault codes, running issues, electrical faults, and poor performance across all makes and models. We use professional OBD2 and dealer-level diagnostic equipment to find the real fault before any parts are replaced.

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★★★★★ 4.9/5 — 87 Google Reviews
🕑 Mon–Sat 8am–8pm
📍 Hackbridge SM6 7HN
Engine Diagnostics South London
Pricing

Transparent pricing — written quote before any work begins

Engine diagnostic scan: £122+VAT. The diagnostic fee is deducted from the repair cost if work is carried out at KITH Cars Garage. A report of all fault codes found and recommended next steps is provided before any repair costs are agreed.

Written quote
Before any work begins
12-month warranty
Parts and labour
Mon–Sat 8am–8pm
Extended hours
OEM-equivalent parts
Manufacturer spec

What does engine diagnostics cover?

An engine diagnostic scan reads fault codes from every ECU in the vehicle — engine management, ABS, airbag, gearbox, body control module, instrument cluster and all other modules. Fault codes give direction but do not always confirm the failed component. Live data analysis, electrical testing, and practical fault-finding are then used to confirm the cause. We diagnose engine warning lights, ABS faults, airbag lights, gearbox faults, DPF and emissions issues, battery drain, non-start faults, misfires, loss of power, poor economy and intermittent electrical problems.

Why fault codes alone are not enough

A fault code says a circuit or sensor is out of range. It does not say the sensor has failed — the wiring, connector, earth, or the component the sensor is measuring may be the actual cause. Replacing a £150 sensor when a £3 connector pin is corroded is a waste of money. We test the circuit before recommending replacement. This is why our diagnostic fee covers the time to find the real cause, not just plug in a scanner.

Engine warning lights — what triggers them

The engine management light (EML) or check engine light illuminates when the engine management ECU detects a value outside the expected range. Common causes: oxygen sensor failure, misfires, DPF regeneration failure, EGR valve faults, turbo boost pressure faults, mass airflow sensor issues, injector faults, timing errors, and catalytic converter efficiency below threshold. Some faults trigger an immediate warning; others only store a code after a certain number of detection cycles.

ABS, airbag and safety system faults

ABS warning lights are most commonly triggered by wheel speed sensor failure. Airbag lights are triggered by seat wiring faults, clockspring failure, impact data stored from a previous collision, or module communication faults. Traction control and stability control lights usually appear alongside ABS faults because they share the same wheel speed sensor data. We scan the relevant system module and test the specific circuit before recommending parts.

Battery drain and non-start diagnosis

A parasitic battery drain is a current draw that continues after the vehicle is locked. Common causes include modules staying awake due to CAN bus communication faults, aftermarket accessories drawing current, faulty relays, alarm systems, and infotainment units. We carry out current clamp testing with the vehicle locked to identify which circuit is drawing abnormal current, then trace the fault within that circuit.

Gearbox and transmission faults

DSG, automatic and CVT gearbox faults are diagnosed using live data — clutch slip values, torque converter lockup, gear shift times, oil temperature and pressure, and clutch pack adaptation values. A diagnostic scan shows whether the gearbox ECU is reporting mechanical wear, a software adaptation fault, or a sensor issue. Fluid condition is also checked as part of every gearbox diagnostic.

Book your engine diagnostics

Unit 1, Soho Mills, London Road, Hackbridge SM6 7HN.
Mon–Sat 8am–8pm.

Get a Free Quote Call 020 4629 9469
020 4629 9469
Hackbridge SM6 7HN
Mon–Sat 8am–8pm
★★★★★ 4.9/5
87 Google reviews
Frequently asked questions

Engine Diagnostics in South London — Questions Answered

Common questions about engine diagnostics at KITH Cars Garage, Hackbridge.

What does the yellow engine warning light mean?

The amber engine management light means the ECU has detected a fault that affects emissions or performance. The car is usually still drivable but should be diagnosed promptly. A red engine warning light or an oil pressure warning is more serious and the car should not be driven.

Can I just clear the fault codes without fixing the fault?

Yes, but the fault code will return. Fault codes are stored when a fault is detected. If the underlying fault is still present, the ECU will detect it again within a few drive cycles and the light will come back on.

How much does an engine diagnostic cost at KITH Cars?

£122+VAT. This fee is deducted from your repair bill if we carry out the repair. We report all fault codes found and advise on recommended repairs before any work begins.

Can you diagnose faults on all car makes?

Yes. Our diagnostic equipment covers all OBD2-compliant vehicles (all cars sold in the UK from 2001 onwards) plus older vehicles on manufacturer-specific protocols. We work on BMW, Mercedes, Audi, VW, Ford, Vauxhall, Toyota, Honda, Renault, Peugeot, Land Rover and all other makes.

My car is running rough. Can diagnostics find the cause?

Usually yes. Rough running is caused by misfires, injector faults, mass airflow sensor issues, vacuum leaks, EGR valve problems, spark plug failure, or timing faults. Live data shows which cylinder is misfiring and whether the fuelling, ignition, or compression is at fault.

What is the difference between reading fault codes and a full diagnostic?

Reading fault codes takes 5 minutes with a basic scanner. A full diagnostic involves fault code reading, live data analysis, electrical circuit testing, and practical fault-finding to confirm the real cause. Fault codes point in a direction — proper diagnosis confirms the fault before parts are ordered.

Can you diagnose faults on my car at your garage?

Yes. We carry out diagnostics at our Hackbridge garage with the vehicle on a ramp. This allows us to test while driving if necessary and access components for electrical testing.

What is an intermittent fault and can you diagnose it?

An intermittent fault only appears under specific conditions — temperature, humidity, vibration, or load. These can be the hardest faults to trace. We use live data logging to capture values during the fault condition, which often reveals the cause even if the fault is not present during the initial diagnostic.

My DPF light is on. Is this a diagnostic job?

Yes. A DPF warning light means the filter has reached a soot loading where automatic regeneration has failed. We diagnose the reason — whether the car has not been driven at speed for long enough, the fuel additive is depleted, or there is an underlying fault preventing regeneration. We then carry out a forced regeneration or advise on DPF cleaning.

What is a CAN bus fault?

Controller Area Network (CAN) bus is the communication network between ECUs in a modern car. A CAN bus fault means one or more modules is not communicating correctly with others. Symptoms include multiple warning lights at once, modules not responding to diagnostic scan, non-start, and electrical systems behaving erratically. These require systematic electrical testing to trace.

Can you diagnose hybrid and electric vehicle faults?

Yes. We diagnose 12V system faults, warning lights, and most electrical faults on hybrids and EVs including Toyota hybrid, Honda hybrid, Nissan Leaf, MG, Hyundai IONIQ and Kia EV6. High-voltage battery diagnostics require specialist equipment and are carried out by a referral partner.

Can you diagnose faults that appeared after an accident?

Yes. Post-accident faults often include airbag module replacement (crash data locked in the old module), parking sensor coding, camera calibration, wiring damage, and blown safety fuses. We scan the vehicle fully after any accident repair.

Why are there multiple warning lights on at once?

Multiple simultaneous warning lights usually indicate a power supply issue (low battery voltage), a CAN bus communication fault, or a shared sensor issue. A battery that is failing can cause modules to report faults simply because the voltage is too low. We test the battery first in this scenario.

Can you diagnose BMW iDrive or Mercedes COMAND system faults?

Yes for standard warning lights and electrical faults related to these systems. Infotainment faults (screen not working, CarPlay connectivity, software crashes) are also diagnosed — usually relating to low voltage, wiring, or module faults.

My car went into limp mode. What causes it?

Limp mode is a protection strategy triggered when the ECU detects a fault that could cause engine or gearbox damage. Common triggers: turbo boost pressure fault, gearbox oil temperature too high, DPF fault, mass airflow sensor failure, or injector fault. The fault code usually makes the cause clear.

Can diagnostics tell me if my head gasket has blown?

Not directly, but combustion analysis, coolant sampling, and live data can indicate a head gasket failure. Coolant temperature rising quickly, sweet exhaust smell, milky oil, rising coolant levels in the expansion tank, and white smoke from a warm engine are all symptoms we check alongside diagnostic data.

Do you offer remote diagnostics?

No — a physical connection to the vehicle's diagnostic port is required. Some systems allow remote access but the vehicle must be at a known location with a wired or Bluetooth interface fitted first.

What is an oxygen sensor fault and how serious is it?

Oxygen sensor faults affect fuel mixture control. A failed upstream sensor causes the engine to run rich or lean, increasing fuel consumption, causing misfires, and damaging the catalytic converter. A failed downstream sensor affects emissions monitoring. Both should be replaced promptly.

Can you reset the service light after a diagnostic?

Yes. We reset all service indicators, oil life monitors, and inspection reminders using manufacturer-level diagnostic access.

Why does my AdBlue warning come on even though I filled it?

If the AdBlue level sensor is faulty, the system may not recognise that the tank has been filled. Alternatively, if the AdBlue quality sensor detects contaminated fluid (water, wrong product), it triggers a fault even with a full tank. We diagnose the cause before recommending parts.

Can you diagnose faults on a car that will not start?

Yes. Non-start diagnosis covers battery, starter motor, immobiliser, crankshaft sensor, camshaft sensor, fuel supply, ECU power, and communication faults. We work through a systematic checklist to confirm the cause.

What information should I give when booking a diagnostic?

Vehicle registration, current warning lights, symptoms (when they started, under what conditions), and whether any recent work has been carried out. The more detail you can give, the more efficiently we can diagnose.

Is a diagnostic included in a service?

A 50-point inspection is included in every interim and full service. This is not the same as a full electronic diagnostic scan. Warning lights present at service are flagged; a full scan requires booking a separate diagnostic appointment.

Can you diagnose faults on a car with no warning lights?

Yes. Faults can be stored in the ECU without triggering a dashboard warning light. We recommend a full vehicle health check scan annually to check for stored faults that have not yet triggered a light.

Do you carry out diagnostic work on the same day?

Yes in most cases. Call 020 4629 9469 to book — morning appointments are generally available and most diagnostic results are available within 2 hours.

What happens after the diagnostic?

We provide a written report of all fault codes, the likely cause based on our testing, and a quote for the recommended repair. You then decide whether to proceed. The diagnostic fee is deducted from the repair bill if work is carried out.

Can I get a second opinion after a main dealer diagnostic?

Yes. We regularly carry out second-opinion diagnostics for customers who have been given a large repair estimate by a main dealer. We diagnose independently and provide our own findings and quote.

How accurate is an OBD2 diagnostic scanner from Amazon?

Consumer OBD2 scanners read generic P codes but cannot access manufacturer-specific codes, live data from all modules, or perform active tests. They miss the majority of vehicle systems. They are useful for a quick check but not for proper fault-finding.

Can a diagnostic fix my car?

Diagnostics find the fault — repairs fix it. A diagnostic result tells you exactly what needs to be done. Without a proper diagnostic, you are guessing and replacing parts that may not be faulty.

Where is KITH Cars Garage for engine diagnostics in South London?

Unit 1, Soho Mills, London Road, Hackbridge SM6 7HN. 5 minutes from Sutton and Wallington, 12 minutes from Croydon, 8 minutes from Mitcham. Open Mon–Sat 8am–8pm. Call 020 4629 9469 or book online.
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Why choose KITH Cars Garage?

Written quote before any work begins
No surprises on collection. Every time.
Workmanship warranty on every repair
12-month parts and labour warranty included.
OEM-equivalent parts to manufacturer spec
Textar, TRW, Brembo, MANN, Mahle, INA.
Pick-up & drop-off across South London
Croydon, Sutton, Mitcham, Carshalton & more.
Mon–Sat 8am–8pm
Extended hours for you.
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Google Reviews

What our customers say

Rated 4.9 ★ on Google — 87+ reviews

★★★★★

“BMW 1 Series needed a new timing chain and clutch. Fair price, courtesy car offered. Stands out from most garages.”

Aaron Konadu
★★★★★

“Professional, no upselling, everything explained clearly. Work completed same day and car runs perfectly.”

Ziaur Rahman
★★★★★

“Rare to find a garage you can truly trust. Fair price, brilliant service. Will always come back.”

Thinushan Keitheswaran
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Areas we serve from Hackbridge

Serving all of South London

Croydon · Sutton · Mitcham · Wallington · Carshalton · Beddington · Thornton Heath · Rosehill · Morden · Purley · Wimbledon · Streatham · Tooting · Norbury · Coulsdon · Cheam · Worcester Park

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