Well upon trying to figure out my COR wiring..... i was jumping BATT from the ECU to the Starter trigger wire which was also attached to 12v switched....i got the truck to fire up for a few sec then nothing. Prior to this I had 12v constantly like i suspect I should for 12 constant. After jumping these wire to get the starter to turn over b/c the key wasn't working I lost the 12v to the 12v constant lead coming for the ECU plug on my homebrew conversion harness. I dont know if that will make sense I will go in to more detail in the AM when I'm more level headed and not so that i prolly friend my ECU. How easy is it to cross a few wires and fry the ECU? From my searching I cant find a way to test it. Any know if/how if can be done?

Jeezzzzzz

 

1st of, you never ohm test directly to ECU or put 12v directly to the ECU

if the key wasnt working, you should have jumped relays or the ignition switch instead (hot wire)

there really isnt any ECU testing. if you can pull a code and go from there. best way imo is to try a known good ECU but check all your fuses 1st because you might have blown a few if your lucky. make sure you check the huge fuses as well 20-30 amp ones that look all fancy if you have any. make sure you didnt fry any relays as well

its alot of checking but it could be fuses and or relays which is better than a ECU unless you got a few good ones around

 

Thanks ToyTech559 you were right. I blew the EFI fuse under the driver kick panel. You say never OHM test the ecu dirrectly...is it ok for me to use the voltage meter to check voltage at/newer the ECU?

 

I might be misunderstanding too. I have 10 FSM pages in front of me(granting, for the 22re), for resistance testing the ECU and then Voltage Testing it for it's readings with all the sensors, ...even a reading to check the ECU itself. But you have to BE SURE you're touching the right pins, each time. Maybe you mean "testing the ECU itself, unplugged completely"?

 

I believe some wrecking yards can check it to see if it's good.

 

you can check voltage at the ecu all day long, u just dont want to use ohm testing because ohm testing means your putting voltage into the circuit and in the ecu case your putting power to it which if you dont know if 5volts or 12 volts is suppose to go in to it, u can fry the ecu. sure if you know what your doing u can perform proper testing of ecu but its not often older toyota ecu ever go bad compared to todays ecu due to toyota letting chevy i believe make them because they could be programmable.

 

Hey Toyotech, .... trust me, I wasn't being sarcastic or anything like that. Just was trying to clarify what you meant. I wasn't speaking of putting power to it, as much as reading the Voltage/Resistance in Ohms that the ECU is registering. Just didn't want him to get confused on that is all. And you're ABSOLUTELY right... even 1 VOLT off can fry parts of them.... I've smelled one that was FA'RIIIIIIED! LOL.

But MANY of the readings you can 'take' there can be very telling of, not so often the ECU's function, but rather, the 'WIRING' in between the ECU and the Sensor in Question, Injectors, etc., ya know?