How severe is this DTC?
A stored P20DD code should be considered severe and addressed as soon as possible. The EAS system may be damaged due to the conditions that contributed to storing the P20DD code.
What are some of the symptoms of the code?
Symptoms of a P20DD fault code may include:
- Decreased engine performance
- Excessive black smoke from the vehicle’s exhaust
- Reduced fuel efficiency
- Other EAS/SCR related codes
What are some common causes of the code?
Causes
of this code may include:
- Faulty EAS fuel pressure sensor
- Bad EAS fuel supply pump
- Open or shorted wiring in the EAS fuel pressure sensor circuit
- Faulty EAS controller/PCM or programming error
What are the troubleshooting steps for P20DD?
A diagnostic scanner, digital volt/ohmmeter (DVOM), and a source of vehicle-specific diagnostic information will be needed to diagnose a P20DD code.
Finding a technical service bulletin (TSB) that matches the vehicle’s year, make, and model; as well as engine size, stored codes, and presented symptoms, could provide helpful diagnostic information.
I like to start my diagnosis with a visual inspection of the EAS wiring harnesses and connectors. Burned or damaged wiring and/or connectors should be repaired or replaced before continuing.
I would continue by plugging the scanner into the vehicle’s diagnostic connector and retrieving all stored codes and relevant freeze frame data. Consider noting this information before clearing the codes. Test drive the vehicle until the PCM enters readiness mode or the code resets.
If the PCM enters readiness mode at this point, the code is intermittent and may be much more difficult to diagnose. If this is the case, the conditions that contributed to storing the code may need to worsen before an accurate diagnosis can be made.
If the code immediately resets, to complete the next step of your diagnosis, you will need to consult your vehicle’s information source for diagnostic flowcharts, connector pinout diagrams, connector face views, as well as component testing procedures and specifications.
Use the DVOM to test (voltage drop) all grounds of the EAS fuel supply system. Continue by testing the power supply to the EAS control system. Test fuses with the circuit loaded to avoid misdiagnosis.
If all system fuses are intact, use the DVOM to test the EAS fuel pressure sensor and sensor circuits. If any of these components do not meet manufacturer specifications, suspect that it has failed.
Don’t forget ground circuits during voltage drop testing