Recently, I performed a routine fluid and filter change on my car, and also took the opportunity to replace the Crankshaft Position Sensor, a component that had been showing intermittent issues for years. While I addressed these maintenance tasks, a new problem arose post-service. The car now exhibits unusual transmission behavior. Specifically, while it drives exceptionally well in reverse and through manual shifts in lower gears (1st to 3rd), it encounters a problem when shifting into 4th. The transmission engages 4th gear smoothly but only holds it for a brief 2-3 seconds before abruptly dropping back down to 3rd gear, accompanied by the dreaded engine light illuminating on the dashboard.
Troubleshooting has been underway. I’ve already dropped the transmission pan twice, meticulously inspecting everything, but found no anomalies. Diagnostic check one, ruling out obvious mechanical issues within the pan, is complete and clear. Similarly, the connections at the Transmission Control Module (TCM) connectors appear to be in good condition, eliminating connection problems as a readily apparent cause.
Given that the car operated flawlessly before this service, the possibility of a failing TCM seems counterintuitive. It’s perplexing why the TCM would suddenly become problematic immediately following a fluid and filter change, and a seemingly unrelated Crankshaft Position Sensor replacement. The thought of a TCM replacement at this stage is unsettling.
I considered seeking professional assistance for a TCM adaptation procedure, a process outlined in the Dodge service manual. However, my attempt to consult with a local dealership’s service department was less than encouraging. Initial contact with a service advisor revealed a lack of familiarity with the TCM adaptation procedure. Further conversation with the service manager yielded similar results; neither had encountered or addressed issues with the LX body transmission, the NAG 1 transmission, or the TCM itself, nor were they aware of the TCM Adaptation Procedure. While they were eager to have me bring the car in for troubleshooting, their admitted lack of experience with these specific components raised serious doubts about their ability to efficiently and accurately diagnose the issue. Entrusting my vehicle to a service department unfamiliar with the very system potentially at fault felt like a gamble.
This situation prompts consideration of alternative diagnostic tools. Could an ELM327 OBD2 scanner, readily available at auto parts retailers like O’Reilly Auto Parts, offer a pathway to understanding this transmission issue? These scanners are popular among DIY car enthusiasts for their ability to read diagnostic trouble codes and access vehicle data. Perhaps an ELM327 OBD2 scanner could provide insights into the engine light and potentially reveal transmission-related codes that could guide further troubleshooting steps. Exploring the capabilities of an ELM327 OBD2 scanner from O’Reilly Auto Parts might be the next logical step in diagnosing this perplexing transmission problem before considering more drastic and potentially unnecessary repairs.
