How severe is this DTC?
A stored P20D6 code should be considered severe and addressed as quickly as possible. The EAS system may be damaged due to the conditions that contributed to storing the P20D6 code.
What are some of the symptoms of the code?
Symptoms of a P20D6 fault code may include:
- Decreased engine performance
- Excessive black smoke from the vehicle’s exhaust
- Reduced energy efficiency
- Other EAS/SCR related codes
What are some common causes of the code?
Causes
of this code may include:
- Faulty EAS fuel injector
- Open or shorted circuits in the EAS fuel injection control circuit
- Insufficient DEF in the EAS tank
- Faulty EAS controller/PCM or programming error
What are the troubleshooting steps for P20D6?
A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be required to diagnose a P20D6 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 useful 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 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 information source for diagnostic flowcharts, connector pinout diagrams, connector face views, as well as component testing procedures and specifications. You can also use your vehicle information source to locate the exact location of the EAS A fuel injector.
Use the DVOM to test (voltage drop) the EAS control system power supply. Test fuses with the circuit loaded to avoid misdiagnosis. If proper power (battery voltage) and ground circuits are discovered, use the scanner to activate the EAS fuel injector (solenoid) and test the output control circuit voltage. If voltage is insufficient, suspect the controller is faulty or encountered a programming error.
If the output voltage circuit is within parameters, use the DVOM to test the EAS fuel injector in question. If the injector does not meet manufacturer specifications, suspect it has failed.
The EAS fuel injector is simply a solenoid injector that sp