CMAX Automatic Transmission Problems

Hey! Sounds rough. I had a similar nightmare with my old Opel Astra a few years back, almost identical symptoms: crazy shifting, warning lights, the whole shebang. The computer probably went into a 'safe' mode, which is what you call emergency mode. Did you check your battery voltage? In my case, it turned out to be undervoltage messing with the transmission control unit. Just a thought!

Regarding your Opel Astra experience, how did the undervoltage specifically manifest and influence the transmission's behavior? Could you explain the correlation between undervoltage and the transmission control unit more precisely?

Okay, so basically, the car's computer (ECU) needs stable voltage to operate correctly. When the voltage drops too low, it can cause all sorts of weird errors, almost like a brain freeze. In my Astra, the low voltage caused the transmission control unit to send incorrect signals, leading to erratic shifting and eventually the limp-home mode. Honestly, it's a pain to diagnose without the proper tools. My advice? Get it to a workshop so they can hook it up to a diagnostic machine. It will save you a lot of time and nerves.

Following your recommendation, I consulted a workshop. The diagnostic assessment revealed that undervoltage was the likely cause for the transmission malfunctions. Repair consisted of a transmission flush and battery replacement, totaling 240€. Thanks for your assistance in resolving this.