Hyundai’s have really odd drive cycles. A drive cycle is a structured test drive where the computer tests all the of the Emission Components and Systems in a step by step process.
Here are 2 methods for completing the drive cycle:
To perform an OBDII Driving cycle do the following: Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run. Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge “No Flow”, Misfire and if closed loop is achieved, Fuel Trim. Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed. Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed. Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed. Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3. Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst. Decelerate. This will perform the same diagnostics as in step 5. Again, don’t press the clutch or brakes or shift gears.
The following is a description of the Hyundai Sonata Drive Cycle. Prior to beginning the drive cycle ensure your Sonata has at least 1/4 to 3/4 tank of gas. An empty or full gas tank will not allow the EVAP monitor to run. Also begin the drive cycle from a cold start; best achieved by leaving your vehicle sitting overnight.
Hyundai Sonata Drive Cycle
STEP 1:
• Make sure check engine light is not on and that there are no stored trouble codes in the computer. Use a scan tool to check for OBD II trouble codes. Any faults founds need to be repaired first.
• Start the engine. Keep the vehicle in Park.
• Idle the engine for 1 1/2 minutes.
STEP 2: (Steady State Driving – Part 1)
• Accelerate within 15 seconds to 50-55 mph (using 1/4 to 3/4 throttle) and keep this speed steady for 2 to 3 minutes.
• Decelerate to 0 mph without braking.
• Idle engine then idle in Drive for 1 to 2 minutes.
STEP 3: (Steady State Driving – Part 2)
• Accelerate within 15 seconds to 50-55 mph (using 1/4 to 3/4 throttle) and keep this speed steady for 10 to 20 minutes.
• Decelerate to 0 mph without braking.
• Idle engine then idle in Drive for 1 to 2 minutes.
STEP 4: (Engine Stop)
• The drive cycle is completed.
• Turn off the engine (key in the OFF position).
If all other emissions systems are functioning properly, completing the drive cycle above should set or make ready (complete) your Hyundai Sonata’s emission monitors. If the emission monitors are still not complete then check for any trouble codes and whether the check engine light is on or not. If faults are found make the appropriate repairs and conduct the drive cycle twice again. Take extreme caution when performing drive cycles on public roadways. Perform the procedure at your own risk.