AdBlue Removal Volvo L70H - SCR Troubleshooting

Volvo L70H loaders are renowned for their reliability, but the AdBlue system can be a problem. When this system fails, the machine loses power. Worse still, it can come to a standstill, bringing your business to a halt. We explain how to solve these problems.

Common symptoms of AdBlue failure on Volvo L70H

During our last service, this 2018 Volvo L70H showed several signs of malfunction. First, a "Check SCR system" warning message appeared on the control screen. SCR" warning message appeared on the control screen, accompanied by a reduction in active power that limited the machine's use. In addition, several fault codes (DTCs) were detected in the engine ECU, such as :

• P20A64 : Reductant Level Sensor "A", Signal plausibility failure

  This code indicates a problem with the AdBlue level sensor. The sensor sends inconsistent or illogical information to the engine control unit (ACM - Aftertreatment Control Module). This malfunction can be caused by a number of factors, including a faulty sensor, oxidized connectors or damaged wiring. Sometimes, poor sensor calibration or general wear and tear can also be to blame. This fault interferes with the accurate assessment of the AdBlue level in the tank, which can trigger alerts or even shut down the SCR system.

• P206A11 : Reductant Quality, Circuit short to ground

  This code indicates a short-circuit in the AdBlue quality sensor circuit. This may be due to damaged insulation on the cables, connectors in poor condition, or internal faults in the sensor itself. Another common cause is the use of AdBlue of poor quality, or contaminated with impurities such as water or solid particles. When the ECU detects poor AdBlue quality, it blocks the SCR system to protect the engine. This leads to a reduction in power and prevents the machine from operating normally.

• P20E016: Reductant Quality Sensor Circuit, Voltage below threshold

  This fault indicates low voltage from the AdBlue quality sensor. This may indicate an insufficient power supply, often due to a wiring problem or faulty connector. In some cases, the sensor itself has failed and can no longer supply the necessary data to the ECU. This prevents the SCR system from checking AdBlue quality correctly, blocking regeneration cycles and leading to an immediate reduction in machine performance.

These faults often prevent the Volvo L70H from operating at peak efficiency. They require rapid, precise intervention to avoid major costs or prolonged downtime.

SCR Diagnosis Volvo L70H - A rigorous method

We applied a methodical process to diagnose the causes of the problem. First, we used an advanced diagnostic tool to read and record all the fault codes present in the engine ECU. Next, we analyzed the data collected to identify faulty components, including SCR sensors, injectors and the AdBlue circuit.

Once the analyses had been completed, we validated the diagnosis by checking sensor values and engine ECU parameters. It became clear that the machine was suffering from a Volvo AdBlue malfunction linked to a combination of faults. This step is essential, as it enables us to plan the intervention precisely and efficiently.

AdBlue removal Volvo L70H - Steps of the procedure

To rectify the defects, we carried out a multi-stage AdBlue Volvo L70H removal. Each phase of the procedure is carried out with the utmost care to guarantee optimum results:

1. Reading and extracting manufacturer data: We retrieved the original files, also known as "dumps", directly from the machine's electronic control unit (ECU). This operation is essential for accessing engine parameters and SCR system settings.
2. Targeted software modification: Once the data had been collected, we deactivated the functions responsible for the restrictions and limitations caused by AdBlue defects. This recalibration work is carried out with precision to ensure that the machine operates correctly.
3. ECU flashing: We then injected the modified program into the engine ECU's memory. This step removes the faults permanently.
4. Final on-site tests: Finally, we tested the machine under real-life conditions with the customer. All fault codes were erased or rendered inactive, and the machine returned to full power.

This process guarantees a reliable and long-lasting Volvo L70H SCR system repair, while eliminating the risk of further AdBlue-related breakdowns.

Common AdBlue system failures on Volvo L70H

Volvo L70H loaders are often confronted with similar breakdowns. Here are the most common problems we encounter on these machines:

• NOx sensor failure: Inconsistent reading of emissions data or sensor completely out of order.
• Clogged AdBlue injector: Injection is insufficient or non-existent, blocking SCR system operation.
• Faulty AdBlue tank heater: At low temperatures, the AdBlue crystallizes and the system stops working.
• SCR regeneration blockage: The machine is unable to complete its regeneration cycle, resulting in a build-up of particulate matter.
• Problems with AdBlue quality or level: often due to faulty or incorrectly calibrated sensors.

These Volvo AdBlue charger faults can be avoided or corrected thanks to rapid diagnosis and repair.