EXHAUST GAS PRESSURE SENSOR
The Exhaust Gas Pressure Sensor (EGPS) or Diesel Particulate Filter (DPF) measures the exhaust gas pressure upstream and downstream of the Particle Filter. By monitoring the pressure difference between these two points, the saturation level of the Particle Filter can be determined. This information allows the emission control system to perform the regeneration of the Particle Filter, according to the European emission standards.
The EGPS allows monitoring the Particulate Filter saturation by measuring the pressure difference before and after the filter. The saturation is also controlled by the Temperature Sensors placed before and after the filter and by an intake Mass Airflow Sensor.
Once the filter’s saturation is determined, the regeneration routine will be started by the system
The EGPS is built with the following components:
A. Sensing element: Electronic circuit
B. Body: Molded with engineering plastic with high resistance
C. Pins: Tin soldered by automated operation
D. Tube before filter
E. Tube after filter
F. Fixing hole
The EGPS generates a linear output that depends on the exhaust gas pressure
difference upstream and downstream of the Particle Filter.
This relationship is shown in the following diagram:
Supply voltage: 5V +/– 0,5V
Temperature range: –20 to 130°C
Max pressure: +/– 400 kPa (30°C for 5s)
- Power off the engine
- Locate the sensor following the pipes coming out of the Particulate Filter
- Disconnect sensor connector
- Disconnect pressure pipes
- Extract fixation screws
- Install the new sensor, check the pressure and application
- Connect pipes and electrical connector
A careful visual inspection is the first step for the diagnosis of a problem.
Check for cracks, bumps or any damage to the sensor’s housing and connecting pipes.
Make sure there is no air leakage in the sensor, pipes and connecting joints.
Also, check for signs of wear in the connector or wirings that could lead to electrical problems.
If none of the problems above have been observed, the failure can be due to a damaged sensing element inside the sensor.
Failure causes can be;
• Breaks, pores or cracks in the pipes.
• Wear signs in the connector or wirings
• Damage of the sensing element causing bad pressure readings
• Air leakage in the sensor
• Wear in the joints between the sensor and the pipes
The malfunction of the EGPS may lead to different problems:
• Dashboard light for both Particulate Filter and Pre-heating (blinking light).
• Unnecessary filter regeneration, leading to reduction of filter life
• Power losses if the sensor is not detecting the filter saturation level
• Increased consumption of oil
- Reduced fuel economy
• Increased pollution emissions