Real diagnostic cases
Practise like in the workshop: symptoms, DTCs, live data and a confirmed root cause.
Battery Discharges Overnight
The engine cranks slowly in the morning. The customer reports the battery has been replaced twice and the problem returns within a...
Engine Cranks But Will Not Start
The engine turns over at normal speed but does not fire. The customer ran out of fuel last week.
P0301 Cylinder 1 Misfire
Rough idle, slight shake and a loss of power. The check engine light is solid, not flashing.
P0171 System Too Lean (Bank 1)
Rough idle, occasional hesitation and a check engine light. Fuel consumption has increased slightly.
P0299 Turbo Underboost
Loss of power, especially on hills. The turbo seems quiet and acceleration is flat.
Battery Warning Light and Weak Charging
The battery warning light glows faintly and the lights dim at idle. It improves when revved.
Multiple Modules Offline (CAN Failure)
The instrument cluster shows several warnings. The engine runs but the ABS, stability and airbag lights are all on. The scanner ca...
Engine Overheating in Traffic
Temperature rises in slow traffic and returns to normal on the open road. The coolant level drops slowly.
ABS Warning and Intermittent Pulses
The ABS light comes on intermittently at low speed and the pedal pulses occasionally when braking gently.
Diesel Hard Starting When Cold
The engine is difficult to start when cold, with grey-white smoke and rough running for a few seconds.
Random Misfire P0300 After City Driving
The engine stumbles at idle after a long period of short city journeys. The check engine light comes on intermittently.
P0172 System Too Rich
Black smoke under acceleration, poor economy and a strong fuel smell from the exhaust.
DPF Warning and Severe Power Loss
The DPF warning light is on and the vehicle is in limp mode with very little power.
Engine Cranks But No Start — Immobilizer
The engine cranks normally but will not fire, and a key/security warning is shown on the cluster.
Hybrid Auxiliary Battery Keeps Going Flat
The hybrid will not start after standing for a few days. The auxiliary (12 V) battery is repeatedly flat though the traction batte...
AC Cold on the Motorway, Warm in Traffic
The air conditioning blows cold when driving but warm when the car is stationary in traffic. The compressor clutch engages normall...