Diagnostics & Fault Finding
Warning lights, electrical gremlins, DPF and EGR faults and non starts. We read the codes, check live data and test the component before anything gets replaced.
Codes Point. Testing Proves.
Plugging in is the easy bit. Anyone can read a code and order the part it names. That is how people end up paying for three sensors and still having the same light on the dash a month later.
We read the stored codes, then watch live data with the engine running to see what each sensor is really reporting. Then we test the component and the wiring to it. Only then do we tell you what needs replacing.
Electrical gremlins, intermittent faults, DPF and EGR problems, limp mode, non starts and lights that come back after someone else cleared them. This is the work we like most.
What Is That Light Trying To Tell You?
Tap any light for what it means, how urgent it is and what we do about it. Red lights mean stop driving and call us. Amber lights mean get it looked at before it turns into a repair.
Engine management light
What it meansThe engine's control unit has logged a fault and put a code in memory. It can be something small like a sensor or a loose connection, or something that will quietly wreck fuel economy and eventually the catalytic converter. A flashing engine light is different again, that usually means a misfire, and driving on it can damage the cat within minutes.
What we doWe plug in, read the live data as well as the stored codes, then test the actual component before we condemn it. You get told what the code is, what it means and what it costs to put right.
Oil pressure light
What it meansThis is the one that ends engines. It means oil is not being pumped around at the pressure the engine needs, so bearings and camshafts are running dry. It is not a low oil level warning, it is a pressure warning, and every minute of running does damage.
What we doStop, switch off and call us. We will recover the vehicle in, check pressure properly with a gauge, and look at the pump, filter and pickup before anything is started again.
Coolant temperature light
What it meansThe engine is running hotter than it should. Usually a coolant leak, a failed thermostat, a water pump on its way out or a cooling fan that has stopped working. Carry on driving and you risk a warped head or a blown head gasket, which turns a small bill into a big one.
What we doWe pressure test the system to find the leak, check the pump, thermostat, fans and radiator, and tell you honestly whether the head gasket has already gone.
Battery charging light
What it meansThe battery is not being charged while the engine runs. Most of the time it is the alternator or the belt driving it. The car will keep running until whatever is left in the battery is gone, then it will stop, usually somewhere inconvenient.
What we doWe test the battery, the alternator output and the charging circuit, so you replace what is actually faulty rather than fitting a battery and having the same problem a week later.
Brake system light
What it meansEither the handbrake is still on, brake fluid is low, or there is a fault in the braking system. Low fluid normally means worn pads or a leak somewhere in the system, and a leak is not something to drive on.
What we doWe check fluid level and condition, inspect pads, discs, hoses and cylinders for leaks, and road test the car before it goes back to you.
ABS light
What it meansNormal braking still works, but the anti lock system has switched itself off. In an emergency stop the wheels can lock. It is usually a wheel speed sensor, damaged wiring near the wheel arch, or the ABS module itself. It is also an MOT failure.
What we doWe read the ABS codes, check the sensors and wiring at each corner, and fix the actual fault rather than clearing the light and hoping.
DPF light
What it meansThe diesel particulate filter is loading up with soot and has not been able to regenerate, usually because the car does mostly short, cold journeys. Caught early it is a straightforward job. Ignored, the filter blocks solid and you are looking at a much bigger bill.
What we doWe check for the underlying cause first, then carry out a forced regeneration or clean, and give you honest advice about whether the car suits the way you drive.
Glow plug light
What it meansOn a diesel, a flashing glow plug light usually means a fault has been logged rather than a preheat problem. It often shows up alongside hard starting when cold, white smoke on start up or a rough first minute of running.
What we doWe test each glow plug and the control relay, check the wiring, and replace only the ones that have actually failed.
Faults We Diagnose.
If it is electrical, intermittent or has already beaten someone else, start here.
Engine Management Lights
Stored and pending codes read, live data checked and the actual component tested before anything is replaced.
DPF & EGR Faults
Blocked filters, failed regeneration, sticking EGR valves and the limp mode they trigger, dealt with properly.
Electrical Fault Finding
Parasitic drains, charging faults, lighting problems and wiring damage traced back to the actual break.
ABS & Traction Faults
Wheel speed sensors, damaged wiring near the arch and module faults. Also a straight MOT failure if left on.
Misfires & Poor Running
Coils, plugs, injectors and vacuum leaks identified with data instead of a parts cannon.
Non Starts
Cranks but will not fire, or will not crank at all. Fuel, spark, compression and security all checked in order.
Light On The Dash? Find Out Why.
Proper diagnostics across Medway and Kent. Codes read, data checked, components tested, then a straight answer.
While It's With Us.
Most people get more than one thing sorted in the same visit. It saves you a second trip and usually saves money on labour too.
Common Questions.
We plug in and read the stored fault codes, then look at live data while the engine runs so we can see what the sensors are actually reporting. From there we test the component and the wiring to it before saying anything is faulty.
You get told what the fault is, what caused it and what it costs to fix, before any work starts.
No, and this is where a lot of money gets wasted. A code points at a circuit, not a part. A code naming a sensor is just as likely to be caused by a broken wire, a corroded plug or an actual mechanical problem the sensor is reporting honestly.
We can, but clearing a light without fixing the cause just means it comes back, and on some faults it means driving around with the engine damaging itself. We would rather find out why it is on.
Yes. Blocked filters, failed valves and regeneration faults are some of the most common diesel problems we see. We find out why it happened, sort it properly and give you honest advice about whether the car suits your driving.
Often, yes. Intermittent electrical faults are the ones that get given up on. It takes patience, live data and following the wiring rather than swapping parts, which is exactly how we approach them.
It depends on the fault and how long it takes to trace. We agree the cost with you up front, and if the repair is done with us that is taken into account. You will never get a surprise bill for investigation time you did not agree to.
Book It In.
Send us the vehicle and what it is doing. We will come back with an honest price and when we can take it.