Air and Eng temp sensor

[benjamindp]

Hi

we're students from Karel de Grote college and we're competing in Formula Student.

Now we've got a problem with our temp sensors. We use a bosch 0 280 130 039 NTC sensor.
For the air temp it's connected to B3 and 0V ENG, eng temp : B4 and 0V ENG.

On both sensor we've always got 4,847V. So when we use the input setup for bosch 2500ohm it's always -43°C.
While heating up the sensor, the voltage drops.
But we never get a realistic value.

There are some other sensors connected to the 0V ENG ( throttle pos, ref, sync, Lambda )
When we measure the voltage on the 0V Eng pin, we measure 4,...V.
Is it normal that we measure a value like this ?

[Sean]

Have you tried disconnecting everything but the air inlet temp sensor and see what you get, then try the same test with the engine temp?

[benjamindp]

Have you tried disconnecting everything but the air inlet temp sensor and see what you get, then try the same test with the engine temp?

Hi Sean, we've tried it but it wasn't changing anything.
So the only cause was that the ECU was broken internal. We've connected another motec m800 and the problem was gone.

Thx for help

[Merlin]

I would suggest you have a damaged 0v line

This is often caused by sending 12v+ down it

It can be repaired by MoTeC .. I have had a few done over time

John P

[adrian]

The easiest way to tell if you have blown a 0V in the ECU is to check continuity between each of the 0V pins (B14, B15 and B16) and the ground pins (A10 and A11). If there's no continuity then the 0V has been damaged.

This usually happens when, as Sean said, when 12V is connected to a 0V pin.

If you want it fixed speak to your local MoTeC dealer and they will organise to have it sent back to us for repair.

[Sean]

This usually happens when, as Merlin said, when 12V is connected to a 0V pin.

Fixed it for you Adrian.