Blowtus

Ok, well I had lots of fun multimetering my ecu today. Determined the tps is the cause of my intermittent stumbling / bucking / hesitating, but also found a few other little bits and pieces. Any explanations / help very appreciated.

the 5th gear switch is always approx 12v, so the car always thinks it's in 5th. Will this only affect the supposed shift light? (which I've never seen) I wonder if mazda australia didn't want it... same story for the shift indicator light, when it should only be 1.5V with ignition on and car off.

The 20'000 mile switch is 12V, (the reading for under 20'000 miles) when the car has done 102,000 kilometres. (and should be reading below 1.5v)
But, the port air solenoid valve is reading below 2.5v (reading for when mileage switch is 'on' apparently over 20'000 miles). Other places I've read that the mileage switch voltages are the other way around... but I find it hard to believe the factory manual has it wrong... any one got an idea whats going on?

My fuel pump resistor relay managed .03v with ignition on and car off, should have been 12v... no idea why it's happening or what it's doing... reads correct with car idling.

the only other anomaly is the intake air temp sensor, supposed to be 2-3v at 20 celcius (68f) but it read 1.3v, in what felt like 15-20 degree ambient temps... not sure if that's an issue or not.

The car appears to be running fine aside from the previously mentioned stumbling, though it takes a while for the idle to stabilise after starting or turning headlights on...

thanks for any info folks.