Symptoms
Check engine light on but the car drives fine: is it dangerous?
The check engine light is on but everything feels normal. What it monitors, when to worry, and how to find out in 2 minutes what it means with an OBD2 reader.
Symptoms
A warning light, smoke, an engine that runs rough or loses power: what your car is trying to tell you, with or without a fault code.
Symptoms
ABS or ESP light on: why a cheap adapter “sees nothing” and how to read C codes
ABS or ESP light on but “no codes” on your OBD2 reader? Standard OBD2 only reads the engine. Where the C codes are, the likely causes and how serious it is.
Symptoms
Flashing check engine light: why you must stop right away
A flashing check engine light is not a simple warning: it signals misfires that can destroy the catalytic converter in a few kilometres. What to do and avoid.
Symptoms
Check engine light on but no code found: pending codes, manufacturer codes, control unit not read
Check engine light on but your OBD2 reader finds no code? Pending or permanent codes, manufacturer codes, another control unit: here is where to look first.
Symptoms
Rough idle and no fault code: where to start
Unstable idle, shaking engine, yet the OBD2 scanner finds nothing. The causes that never set a code, and how to track them down with live sensor data.
Symptoms
Loss of power uphill: understanding limp mode
The car tops out at 2,500 rpm, won't accelerate uphill or on the motorway, then is fine again after a stop. That is limp mode. Common diesel and turbo causes.
Symptoms
Airbag light on: reading the B code, what can be cleared and what cannot
Airbag light on: clock spring, connector under a seat, weak battery. What the B code says, what can be cleared, and why you should never touch the module.
Symptoms
DPF light on: what standard OBD2 can and cannot see, and when driving is no longer enough
DPF light on on a diesel: when a drive on the open road is enough, when you need a garage, and what an OBD2 adapter can or cannot read about the filter itself.
Symptoms
White, blue or black exhaust smoke: what it tells you about your engine
Smoke colour is a diagnosis in itself. White: water or coolant. Blue: oil. Black: too much fuel. Causes, how serious it is, and what to check on your car.
Symptoms
Glow plug light flashing on a diesel: it's not (just) the glow plugs
On most diesels, a glow plug light flashing while driving means an injection or engine management fault, not necessarily the glow plugs. Causes and next steps.
Symptoms
Which warning lights talk to OBD2 and which do not: engine, glow plugs, DPF, ABS, airbag, battery, oil
Check engine, ABS, airbag, oil, battery: which lights an OBD2 adapter can read, which go through another control unit, and which cannot be read at all.