Tried to go out today,

Car ran like s**t. Turned out the temperature sensor spade connector had snapped off. -40degC according to the megasquirt.

BUT what I don't understand is that when I look at the "thermfactor.ini" and it suggests that when the sensor is broken that it resorts to 170degF (Not sure what that is, but it isn't -40degC).

Any idea why with an MS1 this happens? It would be nice open circuit ended up at some kind of manageable temperature.


Any idea why this doesn't work,

Matt

p.s. MS2 daughter board on order.

ADC Value not 0 or 255 ?

what happens if you short the signal wire to ground?

Could be that theres some earth "thing" going on so it didn't recognise a failure

(ground potential difference?)

If the ECU's ground wasn't 100% it could cause it to just think its gone a tad chilly rather than "failed completely open circuit"?

Not sure if the ADC values can be shown on the lappy for air and water temps?

If so have a look at the values at open and short

could be possible to edit the "failure ADC values" on mat and airden so it resorts to sensible values (unless you are planning on driving at the extremes of temps??)

Mine was going a bit thin and lean today due to the unusually high under bonnet air temps
Not sure I can be bothered to get out there with the laptop to see if I can finally fiddle with air density correction...its too bloody hot and I guess it'll be another 2 years till It does it again so I guess I'll just put up with it IF it happens again..LOL

Regards
Rob

sorry poor description.

Completely open circuit (the male of the spade connector on the sensor had come off). I think you are right, there must be some subtle different earths going on (the sensor is at the engine end of things).


You are correct, I am unlikely to go out in my screen-less, heater less, BEC once the temperatures drop below -20degC.


Sorry to be ignorant, but how do I change the .ini to "tell it" to put temps below -10degC to be 80degC,


Should the bottom of the table look like this?

DB 210T ; 243 -94.76
DB 210T ; 244 -97.66
DB 210T ; 245 -100.78
DB 210T ; 246 -104.15
DB 210T ; 247 -107.84
DB 210T ; 248 -111.91
DB 210T ; 249 -116.46
DB 210T ; 250 -121.62
DB 210T ; 251 -127.62
DB 210T ; 252 -134.82
DB 210T ; 253 -143.85
DB 210T ; 254 -156.17
DB 210T ; 255 Sensor Failure - use 170 degF as default

where I have changed all these "210T" from "0T". This equates to 170degF as 40degF is added.

If so this seems like the sort of thing that everyone should do to their table. Fortunately when my sensor broke I was stranded at home, so no hardship. But a failure of the temp sensor needn't be catastropic.

Matt