Dodge Ram 1500 P0123 Code: Gear Shifting Failure and Transmission Stuck in Gear Issue
Hello, I have a 2002 Dodge Ram 1500 with an automatic 4WD 5.9L Hemi engine. I've been experiencing the P012-3 diagnostic trouble code, which was initially diagnosed as a throttle position sensor issue. However, recently while driving, my truck began making an odd noise—like it wasn't gaining momentum—and started shaking severely. After that, it completely stopped moving forward and failed to shift into any gear while traveling on the highway. The vehicle will physically shift into Drive, Reverse, or any gear, but it won’t move when in those gears. For example, if I put it into Drive, the truck doesn't drive forward at all—same for 1st, 2nd, or Reverse. It only functions properly in Neutral and Park. No other diagnostic codes have appeared. I’ve already replaced the transmission fluid and am awaiting a new transmission filter, which will arrive on Monday. I'm wondering if this could be related to the P0123 code or whether it might point to a deeper transmission issue. Any insights or suggestions would be greatly appreciated.
When you shift into Drive, does the engine start moving? This will help determine if the issue is with the transmission itself rather than just the throttle system. However, I suspect there may be additional underlying codes—especially related to transmission functions—that haven't surfaced yet. A full diagnostic scan using a scanner capable of reading all vehicle codes (including transmission-related ones) is strongly recommended. Note: The P0123 code indicates a throttle position sensor issue—check if your airbag warning light is on, as that could be related to the same system or indicate an electrical fault. Also, many basic key-on/off tricks don’t work effectively when transmission problems are involved.