ecu doesn't read the coolant sensor

[zaco2356]

hi there i'am luis i have a yaris 2007 sedan, and i have this issue with the radiator fan that does not turn on at all, so i search on the web how to check that the fan engine is working ect, so i think i did a really stupid thing, i unplug the coolang sensor and connect a wire to the positive of the battery and the other end of that wire put it on the coolang sendor plug and spark come off, after that i start the car and almost did'nt star very poorly, i took it to a mechanic and he put the fan engine and the coolang sensor new and the still going on very poorly when i turn on the car i think the ecu is bad, help me out please

[CTScott]

Hang on - Did you connect the battery to the sensor or to the connector that you unplugged from the sensor?

If you fed power into the connector, you may have cooked that ADC channel on the ECM. The coolant temp sensor is just a resistive sensor, so the ECM only expects to see the voltage drop across the resistor from its low current power feed.

[zaco2356]

Originally Posted by CTScott

Hang on - Did you connect the battery to the sensor or to the connector that you unplugged from the sensor?

If you fed power into the connector, you may have cooked that ADC channel on the ECM. The coolant temp sensor is just a resistive sensor, so the ECM only expects to see the voltage drop across the resistor from its low current power feed.

yes to the connector, so i need to replace the ecu ???

[CTScott]

Originally Posted by zaco2356

yes to the connector, so i need to replace the ecu ???

Check the 10A ETCS, 7.5A ECU-B and 10A ECU-IG fuses. If they are all OK, then I think you may have damaged the ECM.