OBD II Readiness Monitors

OBD Drive Cycles

Universal Drive Cycle

In order for the PCM to properly execute all the readiness monitors on a particular vehicle, an OBD II drive cycle needs to be driven to achieve the enabling conditions for each monitor. The correct drive cycle for your vehicle can vary greatly depending on the vehicle’s year, make, model and manufacturer. The type of monitor you are trying to execute can also dictate the type of driving you need to perform.

Vehicle specific drive cycle information can be found in the manufacturer’s service information, aftermarket service information, various websites and may also be included in the vehicle owner’s manual. Typically, a few days of normal driving, both city and highway, will make the monitors ready. The following generic drive cycle can be used as a guideline if a specific drive cycle is not known. It will assist with resetting monitors when a car specific drive cycle is not available. However, it may not work for all vehicles and readiness monitors. 

• The universal OBD-II drive cycle begins with a cold start (coolant temperature below 122 F, and the coolant and air
      temperature sensors within 11 degrees of one another). This condition is easily achieved by letting the car sit overnight.
• The ignition key must not be left on prior to the cold start. Otherwise the heated oxygen sensor diagnostic may not run.
• Start the engine and idle the engine in drive for two and half minutes, with the A/C and rear defroster on if equipped.
• Turn the A/C and rear defroster off, and accelerate to 55 mph under moderate, constant acceleration. Hold at a steady
      speed for three minutes.
• Decelerate (coast down) to 20 mph without braking or depressing the clutch for manual transmissions.
• Accelerate back to 55-60 mph at 3/4 throttle. Hold at a steady speed for five minutes.
• Decelerate (coast down) to a stop without braking.