The Challenge
For a new development project, a Mercedes-Benz Sprinter with a 2.0-liter OM654 diesel engine was available.
The objective was to transfer the now very popular high-idle function of the IOPEDAL to the IOREVO Idle Control platform, while significantly simplifying integration into the vehicle.
In the previous solution, the reference signal for engine speed is taken directly from the camshaft sensor. This method provides a reliable RPM signal, but it requires an additional cable route from the vehicle interior into the engine compartment.
Especially in modern commercial vehicles, this can make installation more complex. Cables must be routed through existing or newly created pass-throughs and then connected professionally in the engine bay.
The central development question was therefore:
Can the engine speed signal and other safety-relevant vehicle states be captured directly via the CAN bus, or alternatively via the OBD-II interface, and used for high-idle control?
The Solution: Reading Vehicle Data Digitally
With IOREVO Idle Control, we were able to successfully implement both approaches.
Relevant vehicle data could be reliably read and processed in real time, both via direct access to the vehicle CAN bus and via the OBD-II interface.
The captured information includes, among other things:
- current engine speed
- vehicle speed
- selected gear or transmission position
- parking brake status
- engine operating state
- additional available enable and safety signals
This means that IOREVO Idle Control not only has a precise reference signal for engine speed available at all times. At the same time, the system can monitor whether all conditions for safe high-idle operation are fulfilled.
No Additional RPM Signal from the Engine Compartment Required
A key advantage of this solution is that the engine speed reference signal no longer necessarily has to be taken directly from the camshaft sensor.
This means:
- no additional signal cable from the interior to the engine compartment
- no intervention at the camshaft sensor
- reduced wiring effort
- simpler and cleaner installation
- a better foundation for scalable retrofit and series-production solutions
With suitable vehicle configurations, the required data communication can take place directly via a connection inside the vehicle interior or optionally via the OBD-II interface.
As a result, the high-idle function becomes not only more intelligent, but also significantly easier to install.
Safety Through Real-Time Vehicle Data
An increased idle speed may only be activated when the vehicle is in a safe operating state.
By processing CAN bus data, IOREVO Idle Control can continuously check these conditions. The target idle speed is only enabled when all defined requirements are met.
For the Mercedes Sprinter, the following enable conditions were taken into account, among others:
- vehicle speed is 0 km/h
- parking brake is activated
- automatic transmission is in position P
- engine is running
- no safety-relevant lockout condition is active
Only when these conditions are fulfilled can high-idle control be activated and the engine speed raised to the desired target value.
As soon as one of the conditions changes, IOREVO Idle Control can react immediately and deactivate the function. This may occur, for example, when a drive gear is selected, the parking brake is released, or vehicle movement is detected.
More Than a Simple High-Idle System
In a conventional high-idle solution, often only a signal to increase engine speed is output. IOREVO Idle Control, by contrast, combines this function with intelligent evaluation of the actual vehicle state.
The system knows not only the current engine speed, but also the context in which the vehicle is operating.
This makes it possible to implement vehicle- and application-specific control logic. For example, engine speed control can depend on whether:
- the vehicle is safely parked
- an auxiliary unit has been activated
- an external enable signal is present
- a defined battery voltage threshold has been undershot
- a generator or hydraulic pump is to be operated
- additional defined conditions are fulfilled
CAN bus integration therefore creates the basis for significantly more complex and safer control processes than a purely analog solution.
CAN Bus or OBD-II: Two Possible Integration Paths
As part of the project, we were able to read relevant data both directly via the vehicle CAN bus and via the OBD-II interface.
Direct CAN bus access generally offers the possibility of capturing a wide range of vehicle-specific signals at a high update rate.
The OBD-II interface, on the other hand, can provide a particularly convenient connection option depending on the vehicle and application. It is located inside the vehicle interior and can be accessed without additional cable routing into the engine compartment.
Which option is best suited for a specific project depends on several factors, including:
- vehicle model and year of manufacture
- available CAN bus architecture
- required vehicle data
- desired update rate
- installation position of the system
- requirements of the specific application
IOREVO Idle Control offers the flexibility to support different communication paths and vehicle platforms on a project-specific basis.
Precise Engine Speed Control While Stationary
Once the function has been enabled, IOREVO Idle Control takes over control of the increased idle speed.
The current engine speed is continuously compared with the defined target speed. Deviations, for example caused by switching on a generator, hydraulic pump, or compressor, can be automatically compensated.
This keeps engine speed stable even under changing load conditions.
This is particularly important for applications in which auxiliary units require consistent drive power or electrical consumers must be reliably supplied via the alternator.
Suitable for Numerous Vehicle Applications
The combination of high-idle control and CAN bus data processing opens up a wide range of possible applications.
Typical applications include:
- rescue and emergency vehicles
- service and workshop vehicles
- camper and expedition vehicles
- vehicles with additional generators
- hydraulic and compressor applications
- refrigerated vehicles
- mobile power supply systems
- municipal and special-purpose vehicles
Depending on the application, target speed, enable conditions, and safety logic can be configured individually.
IOREVO Idle Control for the Mercedes Sprinter OM654
With this project, we were able to successfully transfer the proven high-idle function of the IOPEDAL to the IOREVO platform while further developing vehicle integration.
The engine speed signal and additional safety-relevant reference values were successfully read, processed, and monitored in real time via both the CAN bus and the OBD-II interface.
The result is an intelligent high-idle solution that:
- can operate without a separate RPM signal from the engine compartment
- reduces installation effort
- monitors several vehicle states simultaneously
- enables engine speed control only under safe conditions
- can be flexibly adapted to different vehicle and body requirements
IOREVO Idle Control combines precise engine speed control with intelligent vehicle data processing for safe, flexible, and installation-friendly high-idle applications.
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