Rt3 Upgrade 651 Na 663 Build 890 Can42 New Review

Rt3 Upgrade 651 Na 663 Build 890 Can42 New Review

If you are still daily-driving a mid-2000s Chrysler product—a Jeep Grand Cherokee (WK), a Dodge Durango (ND), a Chrysler 300, or a Commander—you are likely familiar with the love-hate relationship surrounding the RT3 Navigation Radio. Also known as the REC (Radio Entertainment Center) or the "MyGig" early cousin, the RT3 was cutting-edge in 2005, but by 2025 standards, it feels glacial. However, a legendary firmware upgrade path has emerged from the depths of forum boards and Mopar enthusiast groups: the "651 NA to 663 Build 890 CAN42 New" update.

This is not just a simple patch. It is a complete metamorphosis of your vehicle’s infotainment brain. In this 2,500-word deep dive, we will break down what every component of that keyword means, why you need this upgrade, the risks involved, and the step-by-step process to achieve the holy grail of RT3 performance. rt3 upgrade 651 na 663 build 890 can42 new

The RT3 Build 890 upgrade introduces Adaptive Synchronous Cruise Control (ASCC) , a new operational mode for the CAN42 network. Unlike legacy step-based throttle control (v651), ASCC dynamically harmonizes traction effort across multiple consist units in real-time, reducing in-train forces by up to 40% on variable grades. If you are still daily-driving a mid-2000s Chrysler

A. The "Update Path" (651 $\to$ 663) Moving from version 651 to 663 is not always a direct linear flash. In PSA electronics, firmware updates often require intermediary steps or the use of a "forced update" via the CD changer port (using tools like the PP2000 / Diagbox diagnostic software or a burned firmware CD). Build 890: This is the specific compilation number

B. CAN Bus Compatibility (can42) The most critical part of this string is can42. The RT3 unit relies on the CAN Bus to know when the ignition is on, to control the volume via the steering wheel, and to display trip computer data.

  • Build 890: This is the specific compilation number of the firmware. Manufacturers use build numbers to track exactly which software package was released, often indicating minor bug fixes compared to build 888 or 889.
  • Can42: This refers to the CAN (Controller Area Network) protocol version. The RT3 unit communicates with the car’s body computer (BSI). "Can42" is the specific communication language used by PSA vehicles of that era (approx. 2004–2009). This part of the string ensures the firmware matches the car’s electronics; installing firmware meant for a different CAN version can "brick" the radio or cause the car's dashboard display to malfunction.
  • New: Implies this is a fresh installation or a newly released file.

    • The string describes a specific workflow for updating the firmware and configuration of an RT3 (often labeled RD4) head unit found in PSA Group vehicles (Peugeot and Citroën). This process typically involves flashing the system software to enable new features or correct compatibility issues, specifically relating to the vehicle's CAN Bus communication protocol.

    With 651, recalculating a route after a wrong turn took up to 18 seconds. You would be halfway to the next county before the RT3 chimed. Build 890 optimizes the LZ77 decompression algorithm for the map data. Recals are now sub-5 seconds.