swise83

I have a 92 3.0 4x4 M/T and won't stay running, pulled the ECU and found a burned diode (i believe its a diode). How do i find a replacement diode? Google has not been helpful identifying a part number or replacement.

I'm not opposed to replacing the ECU but i can't find one at a reasonable price.
6.8 (2) D410 C030 Labels

hjj

Hi,
Just a few thoughts...
my best guess it could be a zener diode, in that case 6.8 would be the nominal voltage but they are often marked 6V8. Looking at the size it looks like a higher power diode. a 5 watt diode would be 1N5342AD5.
Are you sure its burned? The discoloration could be from years of heat, as this might get hot in normal operation.
If you can power up the ECU and measure the voltage across the diode, it should be close to 6.8V (if it really is a zener diode).
If you can desolder it, connect it in series with any higher ohm resistor (anything 100 ... 10k maybe) to an 12V battery. With the ring facing the positive terminal you should have around 6.8v across the diode.
But why would it burn in the first place? If it is a zener diode, it is there most probable to stabilize a voltage o to prevent overvoltage. Just guessing, might be a short of a sensor wire to +12V.

swise83

Thank you!! That at least gets me in a direction. I’m sure it’s burned, it was an unmistakable smell.

I’ll check on that info.

swise83

Well I replaced the diode and it didn’t help… now to backtrack why it got fried in the first place

osv

it looks like a cold solder joint, maybe not done by the factory.

does the replacement get hot? does the vehicle run with the lid off of the ecu.

is it throwing a code?