Starting Problem

[simonjones]

Hi I have a 2007 petrol aygo, all standard, engine turns but wont fire, cant get a spark from the plugs and petrol supply pump isnt priming. Crank switch not powering up. Yellow engine management light on. Any ideas?

[Raistlin]

What it actually indicates is that your car’s engine management computer (ECU) has detected a fault with one of the numerous pieces of information it gathers about the engine from a plethora of sensors.

The hardest part to explain is that if ANY of thee sensors detects a fault, the outcome for the driver is the same, i.e. the same CHECK ENGINE light illuminates.

As an example, a typical petrol engined family hatchback may have most, if not all, of the following selection of sensors:

•Coolant Temperature

•Throttle Pedal Position

•Air Temperature

•Inlet Manifold Pressure

•Brake Pedal Position

•Clutch Pedal Position

•Crankshaft Position

•Camshaft Position

•Knock Sensor (detects what used to be called ‘pinking’)

•Air Mass Flow

•Pre and Post Catalytic converter Exhaust gas Oxygen sensors (usually called a ‘Lambda’ sensor)

[simonjones]

Thanks but does that suggest the ecu is faulty or one of the other sensors? If its one of the other sensors surely that would still allow tge engine to start? Really odd as the various computers I have had linked up dont show a fault code.

[eygo]

plug in a diagnostic code reader read and reset the light ,see if the car starts if it does then alls well and good

just have to see if the light comes back on again and starting issues happen again

if it doesn't start then it could be your immobilser at fault or maybe the keys need re programming

someone on here had a similar issue in the last 3 weeks or so