Corolla electrical issues after body work

I'm having a weird issue with my 2020 Toyota Corolla Hybrid. At 155504 km, I'm getting sporadic errors in driving mode, and the malfunction indicator lamp is lighting up intermittently. Sometimes the audio/nav system just dies, or a control unit becomes unresponsive. OBD-II scanner is throwing various codes, all pointing to system failures. Anyone else experienced this?

4 comment(s)

Wow, that sounds frustrating! I had something similar happen in my Corolla (not sure of the year, but same generation). Initially, I also suspected a CAN BUS issue or maybe even a faulty ECU, given the random nature of the failures. Did you try checking the CAN BUS status to see if it is online? Because if it isn't, it may throw seemingly unrelated DTCs.

Thanks for the quick reply! I'm fairly proficient with diagnostics, and I've verified the CAN BUS integrity. However, I did notice the errors started after some minor body work on the driver's side. Could a loose ground or damaged harness cause these sorts of symptoms?

Interesting about the body work. A damaged harness is definitely a possibility. I eventually traced my issue to a defective cable connection on a control unit's BUS system. The connection was loose, causing intermittent signal loss. I'd recommend you bring it to your workshop. At least they can do a proper diagnosis.

Thanks for sharing your experience! I took your advice and brought it in. Turns out it was indeed a corroded connector on the main wiring harness – exactly as you described! Repair cost me 155€, but it's running perfectly now.

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