Blog
Fault codes, sensors and the tricks of diagnostics: what the codes mean, where to start checking and why a cheap adapter sometimes lets you down.
Bad fuel: telling from the live data
The car got worse after a fill-up. Here is how to tell bad fuel from coincidence.
5 September 20263 min
Leaving the adapter plugged in: what it costs
Unplugging it every time is a nuisance. But an adapter left in the socket can flatten the battery over a week of standing.
5 September 20263 min
In winter a car behaves differently: what is normal
High revs on start-up, white vapour, higher consumption — all normal. Here is what is not.
5 September 20263 min
Fuel trims: how to read them
Two numbers that show what the unit thinks of the mixture. They find an air leak before the lamp comes on.
5 September 20263 min
The freeze frame: half a diagnosis in one table
Along with the code the car stores the conditions it was recorded under. That is what tells a one-off from a permanent fault.
5 September 20262 min
Limp mode: the car will not go faster than 60
The revs will not climb, the pedal does nothing, the speed hits a ceiling. That is not a broken gearbox — it is protection.
5 September 20263 min
Fault code P0016: camshaft and crankshaft out of sync
The code sounds worse than it is in half the cases. But it must be checked before you drive on.
4 September 20262 min
P0401: the EGR valve is cleaned more often than replaced
Insufficient recirculation flow. In most cases that is soot, not a dead part.
4 September 20263 min
Fault code P0128: the thermostat or the sensor
The engine never reaches operating temperature. The part is cheap, but replacing it blind is still a bad idea.
4 September 20263 min