No I thought not just that was the changed around the same time the mpg dropped.
Really disappointed with Mazda, I like working on cars and enjoy servicing my cars myself but now it seems you can't even do that yourself without having to visit to the dealership to pay the to reset oil data. Does it matter if the car thinks the oils dirty as long as I know it's clean? Or will I eventually get a warning on the dash to tell me it needs changing?

 

You will eventually get fault codes ( DTC's) logged. This may cause a reduction in power & performance, maybe economy too, Not 100% sure.

DTC P253F:00

Engine oil deteriorated

DETECTION CONDITION
• The PCM calculates the engine oil attenuation based on the fuel injection amount during diesel particulate filter regeneration. If the calculated engine oil attenuation amount reaches the necessary traveled distance for engine oil replacement, the PCM determines that the engine oil amount level is deteriorated.
Diagnostic support note
• The MIL does not illuminate.
• FREEZE FRAME DATA (Mode 2)/Snapshot data is not available.
• The DTC is not stored in the PCM memory.
POSSIBLE CAUSE
• Engine oil attenuation by frequently diesel particulate filter regeneration
• Engine oil data reset procedure does not perform in each engine oil replacements.
• PCM malfunction


I don't have a in depth knowledge or full understanding of the oil data system. I am only sharing my knowledge learned from working for Mazda.

 

Thanks. Your knowledge is appreciated.

 

Had a result in my search to find a way to reset the oil data your self without a visit to Mazda thanks to someone helpful in the Facebook cx5 group. .

1. Ignition on.
2. Connect this terminal to ground.
3. Depress accelerator 5 times. (Confirmed by coil light flashing 5 times).
4. Remove link to ground.
5. Ignition off.
Job done .
Photos courtesy of the helpful guy on facebook