Onboard Diagnostics

DIAGNOSTIC TROUBLE CODES (DTCs)

„OBD2 Drive Cycle - An OBD2 Drive Cycle is an extended set of driving procedures that takes into consideration the various types of driving conditions encountered in real life. These conditions may include starting the vehicle when it is cold, driving the vehicle at a steady speed (cruising), accelerating, etc. An OBD2 Drive Cycle begins when the ignition key is turned “On” (when cold) and ends when the vehicle has been driven in such a way as to have all the “Enabling Criteria” met for all its applicable Monitors. Only those trips that provide the Enabling Criteria for all Monitors applicable to the vehicle to run and complete their individual diagnostic tests qualify as an OBD2 Drive Cycle. OBD2 Drive Cycle requirements vary from one model of vehicle to another. Vehicle manufacturers set these procedures. Consult your vehicle’s service manual for OBD2 Drive Cycle procedures.

Do not confuse a “Trip” Drive Cycle with an OBD2 Drive Cycle. A “Trip” Drive Cycle provides the “Enabling Criteria” for one specific Monitor to run and complete its diagnostic testing. An OBD2 Drive Cycle must meet the “Enabling Criteria” for all Monitors on a particular vehicle to run and complete their diagnostic testing.

„Warm-up Cycle - Vehicle operation after an engine off period where engine temperature rises at least 40°F (22°C) from its temperature before starting, and reaches at least 160°F (70°C). The PCM uses warm-up cycles as a counter to automatically erase a specific code and related data from its memory. When no faults related to the original problem are detected within a specified number of warm-up cycles, the code is erased automatically.

DIAGNOSTIC TROUBLE CODES (DTCs)

Diagnostic Trouble Codes (DTCs) are meant to guide you to the proper service procedure in the vehicle’s service manual. DO NOT replace parts based only on DTCs without first consulting the vehicle’s service manual for proper testing procedures for that particular system, circuit or component.

Diagnostic Trouble Codes (DTCs) are codes that identify a specific problem area.

DTCs are alphanumeric codes that are used to identify a problem that is present in any of the systems that are monitored by the on-board computer (PCM). Each trouble code has an assigned message that identifies the circuit, component or system area where the problem was found.

OBD2 diagnostic trouble codes are made up of five characters:

„The 1st character is a letter (B, C, P or U). It identifies the “main system” where the fault occurred (Body, Chassis, Powertrain, or Network).

„The 2nd character is a numeric digit (0 thru 3). It identifies the “type” of code (Generic or Manufacturer-Specific).

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Craftsman 14063 manual Diagnostic Trouble Codes DTCs