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Failed Smog Test

How To Make Monitors Ready on Ford 2006 F-350 6.0L Diesel

My 2003 F350 6.0L diesel truck will not pass the smog test due to OBD-II monitors incomplete... specifically the misfire monitor. I've been trying to get it to reset by running the drive cycle but have not been able to. It's been several months now without success. The misfire monitor will simply not reset or become complete. There are no trouble codes showing and the smog shop said there are no repairs needed.


In most cases, all the emission monitors should run during normal vehicle operation. However, due to different driving habits, the criteria required to run a monitor may not always be met. Following the Ford F-350 diesel drive cycle below should allow the emission monitors to complete. The drive cycle must be followed accurately. Take extra caution when performing the drive cycle on public roadways. Perform the drive cycle at your own risk. If you feel you might not be able to perform the drive cycle safely, or obey all traffic laws, seek the assistance of a smog check repair station which will be able to perform the drive cycle on a dynamometer and be utilizing specialized OBD II drive cycle readiness tools/scanner/computer.

Your Ford F-350 diesel must have all of its emission monitors READY or COMPLETE in order to pass the smog test (as of the time of this writing). Emission monitors (also known as Readiness Flags) are internal self tests which your Ford F-350 diesel's ECU (engine control unit) conducts to ensure its emission systems are working properly. Typically driving 200-300 miles in both city and highway traffic conditions is sufficient to complete the emission monitors. However at times, a vehicle owner's driving patterns do not match those required for the emission monitors to run; and performing the drive cycle's specific driving pattern is required.

Follow the Ford F-350 diesel drive cycle below. We do recommend performing the drive cycle at twice if after the first attempt all the monitors (including the misfire monitor) do not become Ready or Complete. Note, the Misfire Monitor can only be tested if the fuel gauge reads above one quarter full or the FLI PID is above 15 percent (percentage fuel tank fill). We recommend having the fuel tank at 15% to 75% full during the drive cycle.

How to Perform Drive Cycle for Ford F-350 6.0 Diesel Engine

The Ford F-350 (6.0 liter diesel engine) drive cycle below will "complete" or make "ready" your truck's emission monitors, including the Catalyst monitor, Misfire, Oxygen Sensor monitor, EGR monitor, and Secondary Air Injection.

Start Here:

  1. Turn ignition on, but do not crank engine until WAIT TO START indicator turns off, or 10 seconds has passed (whichever is greater).
  2. Start engine. Allow engine to idle with transmission in Park or Neutral for 40 seconds.
  3. The following conditions must be followed to run certain OBD-II monitors that require engine to be under a load. On A/T models, select OVERDRIVE CANCEL to perform test in 3rd gear. On all models, turn on accessories (headlights, A/C compressor, blower fan, etc.). DO NOT use hazards or PTO. Select an uphill or level road. DO NOT select a downhill road. Driving downhill will unload engine and defeat test.
  4. Accelerate steadily to 3rd gear (A/T) or 4th gear (M/T) and keep engine speed at 1500 RPM for 3 seconds. Accelerate steadily from 35 MPH to 65 MPH in about 15 seconds (A/T) or 11 seconds minimum (M/T). Repeat this procedure 3 times while maintaining conditions set in step 3) . Before proceeding, turn all accessories off and disengage OVERDRIVE CANCEL. On A/T models, go to next step. On M/T models, go to step 6.
  5. On A/T models, drive vehicle in 4th gear continuously for one minute. Accelerate steadily from a full stop to 4th gear and then return to a full stop. Repeat this procedure 10 times, then go to next step.
  6. Before continuing, use NGS tester and select EOT PID from PID/DATA MONITOR & RECORD menu. Ensure EOT PID value is more than 140°F (60°C). Allow engine to idle for 20 seconds in Park or Neutral. Turn ignition off. Start engine and allow engine to idle for 40 seconds in Park or Neutral. Repeat QUICK TEST in appropriate SELF-DIAGNOSTICS article. Drive cycle is complete.
  7. If DTC P1000 is present after performing drive cycle, repeat step 4 maintaining a minimum MFDES PID value of 37 milligrams/stroke with engine speed at more than 1500 RPM for 11 seconds. Also, maintain a minimum MFDES of 37 milligrams/stroke with engine speed at more than 2300 RPM for at least 6 seconds. Repeat step 6. MFDES PID value must remain less than 12 milligrams/stroke for 11 seconds.

Prerequisite: No trouble codes present, Intake Air Temperature (IAT) above 32 Degrees (F); Engine Control Temperature (ECT) is above 167 Degrees (F)

  1. Idle vehicle 4 minutes (achieve closed loop) 
  2. Drive 3 min at steady speed above 50 mph 
  3. Drive 2 min at steady 40 mph 
  4. Drive 2 min at steady 50 mph

Misfire Monitor Repair Verification Drive Cycle

  1. For applications with the Fuel Level Input (FLI) circuit to the PCM (terminal No. 12), check the fuel gauge and the FLI PID on the scan tool (if available). The Misfire Monitor can only be tested if the fuel gauge reads above one quarter full or the FLI PID is above 15 percent (percentage fuel tank fill).
  2. Start the engine and drive the vehicle to a location where speeds can reach 55 to 60 mph and coast down to 40 mph without traffic interference.
  3. Accelerate at wide-open throttle to allow vehicle to shift at red-line (if equipped with a tachometer). Immediately return to normal speed limits.
  4. Perform the following drive procedure three consecutive times. Accelerate on highway to 60 mph. Maintain speed for 30 seconds. Coast down with foot off the accelerator pedal from 60 mph to 40 mph.
  5. Re-run Quick Test.

posted by SmogTips Support 04-10-2018 08:11 PM

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