Here's what you should do instead:
1. Obtain the Diagnostic Trouble Codes (DTCs): You need to know *which* codes are stored. There are several ways to do this:
* OBD-II Scanner: This is the best method. Buy a relatively inexpensive OBD-II scanner from an auto parts store. Plug it into the OBD-II port (usually under the dashboard), and it will read the codes. The scanner will likely also give you a description of what each code means.
* Professional Mechanic: Take your truck to a mechanic. They have the tools and expertise to quickly diagnose the problem.
2. Diagnose the Problem: Once you have the codes, research them online (many websites offer code definitions). This will give you a clue about the potential issue. Do not attempt repairs based solely on online research unless you have significant mechanical experience. Misdiagnosis can exacerbate the problem.
3. Address the Underlying Issue: Resetting the codes without fixing the underlying problem will only temporarily mask the issue. The check engine light (or transmission warning light) will likely return. The solution depends entirely on the DTCs you receive. This could range from a simple fluid change to major internal transmission repair.
4. Clear the Codes (After Repair): *Only* after you've addressed the problem that generated the codes, you can clear them. Many OBD-II scanners have a code clearing function. Alternatively, disconnecting the battery for 30 minutes or so *might* clear them, but this is not guaranteed and is less reliable than using a scanner.
In short: Don't focus on resetting the codes. Focus on *why* those codes appeared in the first place. Get the codes, diagnose the problem, fix the problem, *then* clear the codes. If you're not comfortable diagnosing and repairing transmission problems, a qualified mechanic is the best option.
