Desox/Regen on Develon Equipment

Desox Process for Develon Equipment

Develon equipment with Doosan engines will periodically need a muffler cleaning process, called a Desox, to be performed. It’s very similar to a regen and helps clean the SCR muffler. The process is quite simple and shouldn’t require a service call. As the customer, this can save you time, & time is money! The machine will try to do the process on its own, but if not allowed, the machine will derate & become unusable.

Desox Codes

The two most common codes:

  • P1308:
    • Manual Desox Required
  • P1039:
    • Machine state changed before Desox completed

If either of these two codes are present, the first step is to attempt a force manual Desox.

The Process

You should note that this process can take up to 45 minutes. Be sure to find a spot that is out of the way, because interruption can stop the process and throw the P1039 code.

  1. Adjust settings of machine as below
    1. Warm up machine until temperature of engine oil & coolant oil are 104° F/40° C or more
    2. Maintain machine at low idle
    3. Switch the transmission lever to Neutral & turn on the parking brake
  2. Special Note:
    1. Wheel Loaders: We recommend moving the steering wheel up & out of the way towards the dash. That way it doesn't get bumped in the process
    2. Excavators: Make sure the throttle dial is set to minimum, even if the auto idles is activated.
  3. Turn on the Pilot Cut-off switch
  4. Execute Service DeSOx by pressing the DeSOx switch for 3 seconds located to the right of the operator switch


  • Machine must be running at idle of 800 RPM. Secondary idle for these machines is 1,000/1,200 RPM. Meaning if you operate the machine, pilot control, or steering wheel, the machine jumps to 1,000 RPM & it will not enter Desox mode.
  • Make sure the switch for the pilot cutoff is in the off position. This makes sure there is not chance of any pilot influence to kick the machine out of Desox
  • Park Brake must be in the applied position
  • Engine RPM is set to minimum
  • Carefully exit the machine, avoiding contact with the steering wheel or levers

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