[st_files]

Is the cars' computer actually able to test the components within the car?

Eg. I have a Spark Plugs warning (Yellow triangle - 500mls). Is this indicator based on the actual condition of the spark plugs or is it a purely time based method - ie the plugs have not been replaced for 5 years so the emu indicates they need replacing regardless of their condition? Are all the servicing diganostics just based on time?

 

[xXNealXx]

Some component service intervals are based on the style of driving you do. Others like coolant or brake fluid is time based.

 

[Ronnie]

The cars computer can't test the spark plugs or the brake fluid, as mentioned by Neal it's dependent on conditions