Confused About Diagnosis Box/Testing The Fuel Pump

Technical Area Engine, Transmission, Exhaust etc
2

Hi,

I’ve got a 2003 Mk2.5 MX5 and want to test the fuel pump.

In earlier versions of the MX5 there is a diagnostics box in the engine compartment that can be used to test things and get engine fault codes.

In the Mk2.5 there is an EOBD connector in the driver’s footwell which is presumably now used to get fault codes.

However, there is also a grey box in the engine compartment called DIAGNOSIS.

Does anyone know what this is actually used for? Can it still be used to get fault codes and can I still use it to test the fuel pump (by connecting the GND and F/P terminals)?

Many thanks

 

3

Yes, the fuel pump test should still work using the diagnostic box if the correct terminals are populated, I assume you know which terminals are which. You can also read fault codes from it but in a different way to the pre EOBD cars.

4

Many thanks - I’ve got a diagram of the terminals for the old diagnostic connector in earlier cars. Are the positions still the same?

5

There should be a pinout diagram on the inside of the lid of the diag box.

6

Afraid not - apparently this was left off later cars…

7

Pin locations didn’t change, some may have been deleted off later cars though.