Technical Description of OBD-II Trouble Code
Open Circuit in Reductant/Regeneration Supply Control
What does that signify?
This diagnostic trouble code (DTC) is a generic powertrain code that is applicable to various OBD-II vehicles (1996-newer). This includes vehicles from Mercedes Benz, BMW, Dodge, Volkswagen, Ram, Sprinter, Audi, etc. Although it is a generic code, the specific repair steps may vary depending on the year, make, model, and powertrain configuration.
A stored code P2062 indicates that the powertrain control module (PCM) has detected no voltage in the control circuit for the reductant/regeneration supply pump.
Selective catalyst reduction (SCR) systems inject a reductant compound or diesel exhaust fluid (DEF) into the exhaust system before the diesel particulate filter, NOx trap, and/or the catalytic converter using the reductant injection valve (solenoid). The precise timing of DEF injection increases the temperature of the filtration element, allowing it to function more effectively. This improves the longevity of the filtration element and reduces harmful exhaust emissions released into the atmosphere. The entire SCR system is monitored and controlled by either the PCM or a stand-alone controller that interacts with the PCM. The controller monitors the O2, NOx, and exhaust temperature sensors, among other inputs, to determine the appropriate time for DEF (reductant) injection. Accurate DEF injection is crucial for maintaining exhaust temperature within acceptable limits and optimizing pollutant filtration.
The reductant/regeneration supply pump pressurizes the DEF in the liquid reductant system for use when required. The PCM monitors the supply pump voltage for consistent fluctuation and load percentage. The PCM also monitors one or more pressure sensors in the reductant supply system to detect any leaks.
If the PCM detects no voltage in the reductant/regeneration supply pump control circuit, it will store a code P2062 and may illuminate the malfunction indicator lamp (MIL). The MIL may require multiple ignition cycles with a failure for illumination.
What is the severity of this DTC?
A stored code P2062 should be considered severe and addressed as quickly as possible. It could disable the SCR system, and failure to rectify the conditions that led to the code being stored in a timely manner could result in catalyst damage.
What are some of the symptoms of the code?
Symptoms of a P2062 trouble code may include:
What are some of the common causes of the code?
Possible causes for this code may include:
What are some P2062 troubleshooting steps?
To diagnose a code P2062, you will need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of vehicle-specific diagnostic information.
Refer to your vehicle information source to find a technical service bulletin (TSB) that matches the vehicle’s year, make, and model, as well as the engine size, stored codes, and exhibited symptoms. A TSB can provide helpful diagnostic information.
Use the scanner connected to the vehicle diagnostic connector to retrieve all stored codes and relevant freeze frame data. It is advisable to write down this information before clearing the codes and then test-drive the vehicle until the PCM either enters readiness mode or the code is reset.
If the PCM enters readiness mode at this point, the code is intermittent and may be more challenging to diagnose. In such cases, the conditions that led to the code being stored may need to worsen before an accurate diagnosis can be made.
If the code is immediately reset, the next step in your diagnosis will involve searching your vehicle information source for diagnostic flowcharts, connector pin-out charts, connector face views, and component testing procedures/specifications.
Step 1
Use the DVOM to test the reductant tank supply pump according to the manufacturer’s specifications. Any components that do not test within the maximum allowable parameters should be considered defective.
Step 2
Refer to your vehicle diagnostic information source and use the DVOM to test the voltage of the reductant supply pump (usually battery voltage) when the pump is activated. If current conditions do not allow for automatic activation, use the scanner to manually activate the pump.
Step 3
If the reductant supply pump is functioning properly, use the DVOM to test the input and output signal circuits from the fuse panel, PCM, and ignition switch. Disconnect all controllers before using the DVOM for testing.
