Exhaust Data (EXH)
Monitor the complete exhaust aftertreatment system
Modern diesel vehicles rely on a complex exhaust aftertreatment system to control emissions and maintain engine performance.
The Squarell Exhaust Data Parameter Group provides insight into the operation and condition of systems such as EGR, DOC, DPF, SCR and AdBlue/DEF dosing.
Available parameters differ by vehicle manufacturer and model, but Squarell converts the available information into one harmonised Parameter Group for fleet, maintenance and diagnostic applications.
Specifications
Name: Exhaust Data
Header: $EXH1
Subscription: Yes
Solution: Vehicle Performance
Trigger: Configurable
Output port: Selectable
Typical Applications
The Exhaust Data Parameter Group supports applications such as:
- Exhaust aftertreatment monitoring
- DPF condition monitoring
- SCR performance monitoring
- AdBlue / DEF monitoring
- Emission system diagnostics
- Predictive maintenance
- Workshop planning
- Remote diagnostics
- Vehicle health dashboards
- Uptime monitoring
Key Parameters
NOx & Emission Control
Monitor the performance of the exhaust aftertreatment system.
Typical parameters include:
- NOx before aftertreatment
- NOx after aftertreatment
- SCR efficiency
- EGR valve position
- Exhaust back pressure
Where both upstream and downstream NOx values are available, applications can gain insight into the effectiveness of the SCR system.
AdBlue / DEF System
Monitor the fluid and dosing system used for selective catalytic reduction.
Typical parameters include:
- AdBlue / DEF Tank Level
- AdBlue / DEF Tank Temperature
- DEF Actual Dosing Quantity
- DEF Doser Pressure
- DEF Consumption
- Total DEF Used
These parameters can help identify dosing problems, low-fluid conditions and abnormal consumption.
Diesel Particulate Filter
Monitor the condition and operating state of the DPF.
Typical parameters include:
- DPF Warning Lamp
- DPF Intake Pressure
- DPF Outlet Pressure
- DPF Differential Pressure
- DPF Inlet Temperature
- DPF Outlet Temperature
- Regeneration Status
- Regeneration Requested
- Soot Load
- Ash Load — where available
DPF pressure and temperature information can provide an early indication of increasing filter restriction or incomplete regeneration.
Diesel Oxidation Catalyst
Monitor thermal conditions through the oxidation catalyst.
Typical parameters include:
- DOC Intake Temperature
- DOC Outlet Temperature
These temperatures provide useful context during regeneration and exhaust aftertreatment operation.
SCR System
Monitor the temperature conditions required for effective NOx conversion.
Typical parameters include:
- SCR Intake Temperature
- SCR Outlet Temperature
- SCR Dosing Status
- SCR Efficiency
- NOx Conversion Performance
Exhaust System Conditions
Additional parameters may include:
- Exhaust Gas Pressure
- Exhaust Gas Temperature
- Aftertreatment Fuel Pressure
- Aftertreatment Fuel Rate
- EGR Valve Position
- Exhaust Restriction
The exact parameter set depends on the information made available by the vehicle manufacturer.
The complete Parameter Group and parameter definitions are available to Squarell partners.
Different vehicles provide different levels of detail
Not every manufacturer exposes the same amount of exhaust aftertreatment information.
Some vehicles provide only basic AdBlue and warning information, while others provide extensive data from individual sensors, dosing systems, catalysts and filters.
Squarell uses all reliable information available on the vehicle networks and converts it into the same Exhaust Data structure.
This allows an application to work with one interface while automatically benefiting from additional information when a vehicle provides it.
Visualisation
Exhaust information can be visualised as a complete aftertreatment chain:
Engine → EGR → DOC → DPF → SCR → Tailpipe
Applications can then display values such as:
- temperatures throughout the exhaust system
- DPF pressure difference
- regeneration status
- AdBlue dosing
- NOx before and after SCR
- warning conditions
This makes complex aftertreatment behaviour much easier to understand remotely.
Business Value
The Exhaust Data Parameter Group helps fleet operators to:
- detect aftertreatment problems early
- prevent DPF-related breakdowns
- monitor AdBlue consumption
- identify incomplete regeneration
- improve workshop diagnostics
- reduce unexpected downtime
- monitor SCR performance
- reduce unnecessary workshop visits
- support emission system maintenance
- improve vehicle uptime
Why Squarell?
Exhaust aftertreatment systems are among the most complex systems in a modern commercial vehicle.
The number, location and meaning of sensors differ significantly between manufacturers, and the available CAN information is far from uniform.
Squarell interprets this manufacturer-specific information inside the IVMS and converts it into one harmonised Exhaust Data Parameter Group.
Fleet applications therefore receive usable exhaust system information without having to understand the individual OEM implementation.
