Many stores sell diagnostic fault code readers compatible with a 2005 Jeep Wrangler, including auto parts chains such as Pep Boys and online retailers such as Amazon.com. The On-Board Diagnostic system in this Jeep is compatible with any fault scanner that complies with the OBD II standard.
The OBD II diagnostic standard interface is used on all cars sold in America since 1996, so a fault code reader that works for a 2005 Jeep Wrangler also works on any other Wrangler built after 1996. The OBD II standard was developed primarily to ease diagnostics for emission control systems during vehicle inspections, but it is also in widespread use by mechanics for diagnosis of vehicle issues.
OBD II fault codes report problems with an alphanumeric code that indicates the problem, so it is necessary to have a reference for these codes available to translate the output from the code reader. Many codes are common across manufacturers, however, such as generic codes for powertrain and chassis problems. Generic codes for powertrain problems begin with P0, P2 or P3, while codes for body issues begin with B0 and chassis problems begin with C0. Codes beginning with P1 are manufacturer-specific codes often indicating problems with unique or proprietary aspects of a vehicle.