Mirage ECU problem
The photo below shows a part of failed ECU for a 96 Mirage 115000km.
It didn't communicate with a scanner.The car had an engine fluctuating
problem too.
A local dealership manager asked me for a help sending me a
message below.
"We are having a hard time fixing the car. The ECU and the scanner
didn't communicate at all and we couldn't read the error code.
The engine fluctuated and we've tried our best, replacing a
PCV valve, cleaning the throttle body and changing the PCV valve.
But the problem persists and now we have no idea to go further.”
I'm just a DIYer and I can't make a big deal, but for some reason,
I understand some of the electronics.
When I examined the board,the ripple voltage at the Vcc lines, there
were spikes and ripples and it was natural that it couldn't communicate
with the scanner connected.
Looking at the mounted board,Nichicon's electrolytic capacitors
P series were used. Although no leak could be visually confirmed,
when ESR was examined, one was completely dead and the other
showed high values. I removed the dead one and found the leaked
liquid was solidified on the board as shown in the first picture, and it
showed about 1kΩ/1mm distance by an ohm meter as below.
The car now runs fine, but the problem of fluctuating idling has not
been solved. I had already done an experiment to find out the
cause of it using a home made smoke machine. It was caused by
a worn O ring used at the throttle shaft. The air was absorbed there.
It didn't communicate with a scanner.The car had an engine fluctuating
problem too.
message below.
"We are having a hard time fixing the car. The ECU and the scanner
didn't communicate at all and we couldn't read the error code.
The engine fluctuated and we've tried our best, replacing a
PCV valve, cleaning the throttle body and changing the PCV valve.
But the problem persists and now we have no idea to go further.”
I'm just a DIYer and I can't make a big deal, but for some reason,
I understand some of the electronics.
When I examined the board,the ripple voltage at the Vcc lines, there
were spikes and ripples and it was natural that it couldn't communicate
with the scanner connected.
Looking at the mounted board,Nichicon's electrolytic capacitors
P series were used. Although no leak could be visually confirmed,
when ESR was examined, one was completely dead and the other
showed high values. I removed the dead one and found the leaked
liquid was solidified on the board as shown in the first picture, and it
showed about 1kΩ/1mm distance by an ohm meter as below.
been solved. I had already done an experiment to find out the
cause of it using a home made smoke machine. It was caused by
a worn O ring used at the throttle shaft. The air was absorbed there.
