I know I posted about the same issues before, but it was in the wrong chat and I got more information regarding the issue now. Let's get right into it

Hey guys! I'm having major intermittent issues with my rx8. My car would randomly stall when I'm driving and all the lights on the dash would come on including the immobilizer flashing. This would then not let me start the car (since the immobilizer is blocking me from cranking the engine). After a few minutes, the issue goes away and the car starts right up without any issues. Here are the codes I got from Forscan when it stalled recently:

TCM (traction control module): U0100 Lost communication with PCM (ECU)

RKE (remote keyless entry): U0100 Lost communication with PCM (ECU)

EPS (electronic power steering): U1900 CAN communication Bus fault - Receiving error

IC (Instrument cluster): U1900 Missing the CAN message from PCM (ECU)


All of the codes are pointing at the PCM (ECU), but the issue is intermittent, so I don't know if it's really the PCM (ECU) the issue. I did let the car idle and shaked the PCM (ECU) connectors to make the car "stall" like it does when the issue happens, but nothing happened.

You guys got any recommendations or tips I could do to find the issue?

Thanks!

 

Have you checked battery terminals for dirt and snug fit? Maybe clean them up while you're there. Simple things first.

If it goes away after some time, that points to a heat issue, but I'm not sure what would cause the ECU to overheat. Does this only happen at speed or only while sitting still or any other patterns you might have noticed?

 

Hey! I'm sure the battery terminals are super tight since I check them regularly. For when the issue happens, it happens after like 10-15 minutes of driving the car which is pretty weird. But, this what's going on now. During winter, the car never wanted to turn on since the immobilizer was constantly stopping me from turning it on. When summer rolled around, the car started to be fine and drive fine until a few weeks ago when it started to stall and not work again intermittently.

 

Try tracing your ground wires to be sure they're not corroded or loose.
Also, did you grab your terminals to check if they're tight?
The OEM strap type will stretch over time and even though the bolts are tight, they can still be loose.

 

I made sure the terminals are shiny and really really well tightened to the terminals. And for the ground, is the ECU ground the one at the top left of the engine bay? I pretty sure it's alright. If there's any more ground I should check, can you guys tell me which one? Here's a pic of the ground I'm talking about: