coil test
 

Tested my coils last week and all four failed on the c-b terminals - all were open cicuit! which according to the mazda coil test procedure means they are defective.
I bought four new coils, tested them, and they all failed on the same part of the test! I took one of my original coils to a mazda dealer who tested it, his conclusion was that " it tested the same as a new coil but also the same as a coil known to be faulty"
How can this be? does he not know what he is doing or is the mazda test procedure unreliable.

Any suggestions?

Not really.......maybe they did it wrong?
How did they measure it....with what exactly? If a simple handheld meter was used, what scale was it on and was that battery in it good?

I only spoke to the service desk not the person who did the test but will seek him out and get to the bottom of it tommorrow. seems crazy to say that a new coil tests the same as a known faulty one.

I just tested two coils that came off my car a few years ago, and they tested within spec, according to the PDF -

A-B = 1.4 kohms
B-C = 10 Mohms
C-A = infinite

Although the 10 Mohms is getting close to infinite. Not sure what is typical there.