The Ford Powerstroke Diesel loosely follows the On Board Diagnostic system known as OBD/II (OBD-2). Because the PSD is weight rated above 8800lbs, the vehicle is not required to follow the structure exactly. Ford uses their own "manufacturer specific" coding system that follows the OBD/II template.

Because of the 8800lb exemption, many generic OBD/II code readers cannot retrieve the manufacturer codes from the computer. Scanners that are KNOWN to work are:

  • Auto Enginuity OBD tool (with Enhanced Ford activation)
  • Superchips 1705 tuner


First digit structure is as follows:


  • Pxxxx for powertrain
  • Bxxxx for body
  • Cxxxx for chassis
  • Uxxxx for future systems

Second digit structure is:


  • P0xxx Government required codes
  • P1xxx Manufacturer codes for additional emission system function, not required but reported to the government


Third digit structure is:


  • Px1xx measurement of air and fuel
  • Px2xx measurement of air and fuel
  • Px3xx ignition system
  • Px4xx additional emission control
  • Px5xx speed and idle regulation
  • Px6xx computer and output signals
  • Px7xx transmission
  • Px8xx transmission
  • Px9xx control modules, input and output signals

The fourth and fifth digits designate the individual components and systems.

Anatomy of the Diagnostic Trouble Code

A DTC is made up of 5 digits. The figure below demonstrates the
composition of a DTC. With this information it is easier to trouble shoot a DTC
without knowing the description of the code.
X X X X X

First Digit


Second Digit

  • 0-SAE
  • 1-MFG

Third Digit

  • 1-Fuel and Air Metering
  • 2-Fuel and Air Metering (Injector circuit)
  • 3-Ignition Systems or Misfire
  • 4-Auxiliary Emission Controls
  • 5-Vehicle Speed Control and Idle Control System
  • 6-Computer Output Circuit
  • 7-Transmission System
  • 8-Transmission

Fourth and Fifth Digit

Fault 00-99

Types of DTC's

There are two categories of DTC's that apply to OBD II. They are listed
below with Type A being the more severe.

Type A

  • 1. Emissions related.
  • 2. Requests illumination of the MIL after one failed driving cycle.
  • 3. Stores a freeze frame DTC after one failed driving cycle.

Type B

  • 1. Emissions related.
  • 2. Sets a Pending Trouble Code after one failed driving cycle.
  • 3. Clears a Pending Trouble Code after one successful driving cycle.
  • 4. Turns on the MIL after two consecutive failed driving cycles.
  • 5. Stores a freeze frame after two consecutive failed driving cycles.

On to the Codes!