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I got a problem with a car and i would like some kind of ideas, if any1 got any ...
Car is a Mitsubishi Colt 2007 - 4A90 engine.
Long story short ... car runs fine.
But from time to time, under accelerating the red temp light on the dash coming ON, and the engine is stalling, like a shut off,
if you keep the gas pedal pushed the power is coming up, but if you don't the engine will shut off.
It starts right up everytime.
When all this happen a "U1073 - Bus OFF" fault pops up in several modules.
The point is that my Can Bus High and Low are looking fine at the DLC connector ... i scope them, when the engine is stalling,
and it doesn't seems anything wrong, also i am not losing com with any module when the engine is stalling.
PCM is present, SRS, ABS, BCM, cluster etc ... all have com when engine stalling.
I am little out of ideas, and i would like to know if anyone got anything in mind ...
Do you have access to a network diagram?
What modules specifically are showing a fault code?
Sounds like maybe a connector or wire is bad. All the DLC tells you is that the can network is still alive, but it doesn't show if it's good throughout.
I found online a wiring diagram ...
there is just 1 Can Bus High and Can Bus Low in this car ...
As i saw at that diagram the 2 gates modules that have the 120Ohm resistors inside
are the PCM and the cluster.
All others are connected to them ...
The first module,almost all the time, that "U1073 - Bus Off" fault pops up is the Body control module (or Etacs as Mitsubishi is calling the BCM)
and the Immobilizer control module.
The point is that i am not lossing connection to any module when the fault appear !! ... hmmm ...
Back probe the can line at the bcm and see if you can catch anything with the scope. I have no idea about code setting criteria, but it may be a short enough interruption that the scan tool doesn’t report a no comm
with engine temp lite coming on I would check ECT sensor with scantool see if running high like 230 240 when engine stalls and if car isn't over heating and therstat is open u may have sensor bad or grounded wire 5volt ref killing motor shutting down pcm intermittent
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