How Severe Is This DTC?
A stored P205F code should be considered severe and addressed as quickly as possible. The SCR system may be disabled because of this. Catalyst damage can occur if the conditions that contributed to the code being stored are not rectified in a timely manner.
What Are Some Symptoms of the Code?
Symptoms of a P205F trouble code may include:
- Reduced fuel efficiency
- Excessive black smoke from the vehicle’s exhaust
- Decreased engine performance
- Other SCR-related codes
What Are Some Common Causes of the Code?
Causes
of this code may include:
- Faulty reductant pressure sensor
- Faulty reductant system injector
- Incorrect or inadequate DEF
- Open or shorted circuits in the reductant system
- Faulty SCR controller/PCM or programming error
What Are the P205F Troubleshooting Steps?
A diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information source will be needed to diagnose a P205F code.
You can use your vehicle information source to locate a Technical Service Bulletin (TSB) that matches the vehicle’s year, make, and model; as well as engine size, stored codes, and presented symptoms. If you find one, it may provide helpful diagnostic information.
Use the scanner (connected to the vehicle’s diagnostic connector) to retrieve all stored codes and relevant freeze frame data. It’s a good idea to record this information before clearing the codes, then test drive the vehicle until the PCM enters readiness mode or the code resets.
If the PCM enters readiness mode at that point, the code is intermittent and may be much more difficult to diagnose. If this is the case, the conditions that contributed to the code being stored may need to worsen before an accurate diagnosis can be made.
If the code immediately resets, the next step in your diagnosis will require you to search your vehicle information source for diagnostic flowcharts, connector pinout diagrams, connector face views, and component testing procedures/specifications.
Step 1
Use the DVOM to test the reductant pressure sensor according to manufacturer specifications. Components that do not test within allowed parameters should be considered faulty.
Step 2
If the actual reductant system pressure meets specifications, the P205F code persists, and the sensors are operational, use the DVOM to test the input and output signal circuits between the SCR system sensors and the PCM/SCR controller. Disconnect all controllers before using the DVOM for testing.
Reductant system performance codes are often attributed to low or incorrect DEF