GrandVoyager Nav System & ECU Failures Fixed Here

A few months back my 2000 Town&Country showed similar symptoms, totally dead nav system and multiple electrical fault codes. After troubleshooting, it turned out to be a software malfunction in the main control unit. I have some experience working on these models, but this was beyond basic DIY fixes. The workshop did a full diagnostic scan which revealed corrupted ECU software causing communication errors between modules. They performed a complete software reset and recalibration of the control unit which resolved all the electrical gremlins. Total cost was 240€ for the programming work. Since then, everything has worked perfectly, no more error codes or navigation issues. Before suggesting specific fixes, could you share: Have you scanned for specific error codes? Does the electrical issue happen more when the engine is hot or cold? Are there any other electrical symptoms like flickering lights or battery drain? Has the car been in any accidents or had water damage? This information would help determine if your issue matches what I experienced with the ECU problems or if it might be something else entirely.

My GrandVoyager has only 125450 KM and had its last service 3 months ago. I did get the codes scanned, showing P1234, P0700, and U0100. Issues definitely get worse when the engine is hot, particularly after 30 min of driving. No accidents or water damage, but I notice the dashboard lights flicker occasionally and the battery seems to drain faster than normal when parked. The onboard diagnostics also show multiple communication errors between modules. Starting to think this matches your experience with the control module software bug. A full software update and recalibration might be the solution rather than replacing expensive components. Will get it checked at a shop that specializes in automotive electrical systems and control unit programming. Thanks for sharing your fix, helps narrow down the likely cause.

Thanks for those details, those symptoms and error codes are nearly identical to what I experienced with my Town&Country. The flickering dashboard and battery drain also match perfectly with the software malfunction I dealt with. Since getting the software reset and recalibration done, my vehicle software has been stable with no more communication errors between modules. The mechanic explained that heat-related issues often point to corrupted ECU programming rather than hardware failures. A specialized shop should be able to perform the software update procedure, which involves: Full system diagnostic scan, Backup of current ECU data, Complete software reset, Recalibration of module communication, Final testing under load The repair cost is usually reasonable compared to replacing components. My 240€ fix has held up well for over 8 months now. Make sure to find a shop with experience in vehicle software troubleshooting and ECU programming for these models. Keep in mind that after the software update, you may need to reset some personal settings like radio presets and climate control preferences, as these often get cleared during the process.

Thanks everyone for the detailed input. After comparing my symptoms with your experience, I'm convinced the control unit software is the culprit. The error codes, heat-related issues, and communication problems between modules all point to a software malfunction rather than failing hardware. The onboard diagnostics showing multiple electrical faults and module communication errors really matches what you described. Reassuring to hear that a software update and recalibration fixed these exact issues without needing expensive parts replaced. I've found a reputable shop that specializes in automotive electrical systems and control unit programming. Will have them perform the full diagnostic scan and software reset procedure. The 240€ cost seems reasonable considering what could have been a much more expensive repair. Will update once I get the work done. Really helpful to know what to expect with the repair process and that the fix has proven reliable in your case. Hoping for similar success with resolving these electrical gremlins through a proper software update.