总裁俱乐部app

OBD Codes
Your OBD-II Trouble Codes Repair Site

P202E Reductant Injection Valve Circ Range/Perf B1U1

OBD-II Trouble Code Technical Description

Article by
Stephen Darby
Stephen Darby
ASE Certified Technician

Reductant Injection Valve Circuit Range/Performance Bank 1 Unit 1

What does that mean?

This diagnostic trouble code (DTC) is a generic powertrain code and applies to many OBD-II vehicles (1996-newer). That may include but is not limited to vehicles from Ford, Mercedes Benz, Sprinter, Smart, Ram, etc. Although generic, the exact repair steps may vary depending on year, make, model and powertrain configuration.


 

总裁俱乐部appA stored code P202E means that the powertrain control module (PCM) has detected abnormal voltage in the control circuit for the reductant injection valve for engine bank #1 and selective catalyst reduction (SCR) system one. Bank one refers to the bank of the engine that contains the #1 cylinder.

总裁俱乐部appThe catalyst system is responsible for reduction of (basically) all exhaust emissions although certain applications are also equipped with a NOx trap.

总裁俱乐部appExhaust gas recirculation (EGR) systems go another step further in the reduction of NOx. Nevertheless, today's larger and more powerful diesel engines cannot meet strict federal (U.S.) emission standards with the EGR, diesel particulate filter/catalytic converter, and NOx trap alone. It was for this reason that selective catalytic reduction (SCR) systems were invented.

SCR systems inject a reductant compound or a diesel exhaust fluid (DEF) into the exhaust in front of the diesel particulate filter, NOx trap, and/or the catalytic converter via the reductant injection valve (solenoid). The precisely timed DEF injection elevates the temperature of the filtration element and allows it to perform more efficiently. It enhances filtration element longevity and allows fewer harmful exhaust emissions to be released into the atmosphere.

The entire SCR system is monitored and controlled by either the PCM or a stand-alone controller (which interacts with the PCM). Either way, the controller monitors the O2, NOx, and exhaust temperature sensors (as well as other inputs) to determine the appropriate time for DEF (reductant) injection. Precise DEF injection is necessary to maintain exhaust temperature within acceptable parameters and optimize pollutant filtration.

Reductant heaters are used to prevent diesel exhaust fluid from freezing during extreme temperatures. These heaters are typically located in the DEF reservoir and/or the reductant injector supply hose/s.

If the PCM detects voltage on the control circuit for the reductant injection valve that is outside the normal range or performance parameters for engine bank 1 unit 1, a code P202E will be stored and a malfunction indicator lamp may be illuminated.


P202E

What is the severity of this DTC?

总裁俱乐部appA stored code P202E should be considered severe and addressed as quickly as possible. The SCR system could be disabled because of it. Catalyst damage could result if the conditions which contributed to the code being stored are not rectified in a timely manner.

What are some of the symptoms of the code?

Symptoms of a P202E trouble code may include:

What are some of the common causes of the code?

总裁俱乐部appCauses for this code may include:

What are some P202E troubleshooting steps?

总裁俱乐部appYou will need access to a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of vehicle specific diagnostic information to diagnose a code P202E.

总裁俱乐部appIf you can find a technical service bulletin (TSB) that matches the vehicle year, make, and model; as well as the engine size, code/s stored, and symptoms exhibited, it could yield helpful diagnostic information.

You will want to begin your diagnosis with a visual inspection of the reductant heater system harnesses and connectors. Burnt or damaged wiring and or connectors should be repaired or replaced before proceeding.

总裁俱乐部appProceed by hooking the scanner to the vehicle diagnostic connector and retrieving all stored codes and pertinent freeze frame data. Write this information down before clearing the codes and test driving the vehicle until the PCM either enters readiness mode or the code is reset.

The code is intermittent and may be much more difficult to diagnose (at this time), if the PCM enters readiness mode. If this is the case, the conditions which contributed to the code being stored may need to worsen before an accurate diagnosis can be made.

Should the code be reset, search your source of vehicle information to obtain diagnostic flow charts, connector pin out charts, connector face views, as well as component testing procedures and specifications. This information will be required to complete the next step of your diagnosis.

Use the DVOM to test the power supply to the SCR control system. Test fuses with the circuit loaded to avoid misdiagnosis. If the appropriate power (battery voltage) and ground circuits are discovered, use the scanner to activate the reductant injector valve (solenoid) and test output control circuit voltage. If voltage is insufficient, suspect that the controller is bad or has experienced a programming error.

总裁俱乐部appIf the voltage output circuit is within parameters, use the DVOM to test the reductant injection valve in question. If the valve fails to meet manufacturer's specifications, suspect that it has failed.

Related DTC Discussions

Need more help with a P202E code?

If you still need help regarding the P202E trouble code, please post your question in our FREE car repair forums.

NOTE: This information is presented for information purposes only. It is not intended as repair advice and we are not responsible for any actions you take on any vehicle. All information on this site is copyright protected.

手机棋牌输了几百万 我爱彩票邀请码是多少 怎么购买手机赌博软件 怎么样进入赌单双软件 快钱彩票官网 怎么下载波克棋牌 手机版彩票过滤工具 快乐棋牌游戏 我想查查彩票开奖结果 怎样买世界杯足球彩票