The Lambda Tronic Operating System Instruction Manual

LOVTEC’s LPG Lambda Tronic operating system is one of the most modern operating systems for LPG fuelled vehicles on the market, and is fully compliant under EHK 67.01.

The control unit (CU) is made up of the newest hardware, extremely resistant to all sorts of interruption, breakdown, or faulty integration, and is run on a fully programmable Microchip RISC processor.

The Autotest function precisely measures the state of the manifold framework and electrical connections of the converted vehicle.

When connected to PC, the unit can measure oscillation of the Lamda sensor on gasoline in two modes and use the recorded entries for the emulation of the sensors during use with LPG.

The unit has four adjustable TPS control settings. The ability to choose control speeds, as well define the parameters in each of the control settings allows for the optimal set up of the vehicle’s performance, while attaining a minimal emissions count.

Although the unit has an Autotest function, it only reaches its full potential when connected to PC.

The unit is delivered with a basic factory setting of 70 steps from the lower limit, unconnected to the TPS, with Lambda 1V = rich.   This setting is also referred to as “Factory Reset”.

TPS must be grounded if it is not connected.

It is not recommended to mount the unit in the area around the engine.

1. Set up procedure for AUTOTEST mode.

1.1     After completely installing all mechanical and electrical elements, connect the unit to the actuator and +12V battery. The units LED indicators flash in the order of the factory settings: 1.orange / 2.orange / 3.green / 4.orange / pause / red / green / see table “LED Signals During Start Up” and set up the stepper motor in its starting position of 70 steps from the lower limit.

1.2     Disconnect the unit from the power source. (Remove it from the connector, or remove the fuse).

1.3     In the“Gasoline” position, warm up the motor with gasoline.

1.4     With the unit disconnected, switch to LPG, set the regulator so that the motor runs on LPG at a high RPM rate, without stalling on idle (the idle nozzle should be turned approximately three full rotations).

1.5     Turn off the engine and reconnect the unit. If the unit has not been previously connected to LPG, it is still in “factory settings” mode, and will carry out an autotest. The unit will carry out an autotest only when in factory settings mode and when the LED light first blinks orange – see below.

2. Autotest

2.1       Phase 1 – increased RPM

Start with gasoline, increase RPM to 2500 and switch manually to LPG. 

After switching, ignore the Lambda signal for three seconds. The unit then begins to regulate the mixture by increasing RPM, and will look for the optimal position for the stepper motor. This is indicated by about 10 changes from red LED(rich) to green LED(lean). Whenever the unit flashes orange, the process is complete. It is important to move on to the next mode within 5 seconds of the flashing. If the unit continues to flash orange, it means that it was not possible for the stepper motor to create an optimal mixture, and that the autotest was unsuccessful. See Trouble-shooting. If you want to attempt another autotest without having to reset, the unit must be disconnected from the power source (disconnect the cable or remove the fuse) until the unit is switched back from LPG to gasoline.

2.2       Phase 2 - idle

Ease up on the gas pedal. The unit searches for the optimal position and TPS reading while idling. Ten changes from rich to lean. At the end, LED flashes orange. If the flashing continues, it doesn’t mean that the autotest was unsuccessful, but rather the idle and high RPM zones are not in agreement. See Trouble-shooting.

2.3       Phase 3 – setting up a TPS maximum

Fully step on the gas pedal for a short interval (pay attention to RPM!) The unit gets a reading of the maximum TPS performance. If the LED flashes, the test has been completed successfully. If the LED is constantly lit, TPS is not connected, and the test is stopped, but not considered to be in error. In this three-phase set up process, the LED indicates green (lean) or red (rich).After completing set-up, switch back to gasoline, and the settings will be placed into the memory of the unit. It is recommended to disconnect the unit from the 12V battery and verify the results according to point 3 “LED Signals During Start Up”.

Unconnected (grounded) TPS means that all borders have been shifted to the limit on the right, and that the TPS has a voltage of zero and  “StaCU” is increasing – See “Tuning” and “Actual” Panels” below. The unit can be controlled by PC.After autotest, the optimal mechanical set-up of the system regulates the unit to a maximum limit of between 40 and 100 for lower performance, and 40 and 120 for idling, with a limit range of 50 steps. Control can only take place with the help of a PC. See  manual.A properly functioning unit flashes during all operational LPG modes.If continually lit, an error is being registered – this has no effect on the functionality of the unit. See Basic Information about Interfacing the “Tronic” Unit to PC.The entire process of the Autotest can be monitored with the help of the PC. If the unit flashes orange, the autotest phase has been successfully completed. If the unit LED is continually lit, that phase has not been successfully completed. At this moment the readings are blocked for voltage values and the position of the motor.

3. LED Signals During Start Up

New units and restarted units flash in the same order: 1. orange / 2.orange / 3.green / 4.orange / pause – after the pause, the process will be the same / red – stepper motor closes / green – stepper motor opens, sets starting position, stepper motor test.

4. Trouble-shooting: Errors, Causes and Solutions.

4.1       The first flashes of the LED are red 

Means that the autotest did not determine an advantageous stepper motor position in the higher RPM area. The unit remains with the factory settings. An Autotest can not take place. In order to conduct an autotest, the unit will have to be turned on and off three times – see Table “LED Signals During Start Up” or with the help of the PC.

4.2       Phase 1 – increasing RPM

Indicators are continually lit orange after the 2500 RPM test.

The unit does not change from red to green when increasing RPM.

Causes:    1. Faulty or incomplete warming of the Lambda.

Monitor during the change switch to gasoline. The voltmeter on the white wire, measuring 0-3V, measure against the ground.

                2. Badly connected signal from the Lambda sensor.

Determine whether there is a signal when switching to gasoline. If so, the injector was disconnected with it, or only the warming Lambda itself was disconnected.The Lambda will briefly show.

                3. Not possible to create a mixture with the stepper motor.

Before turning orange, a long period of green – mixture too lean:

Determine whether there is enough fuel in the tank, and if it flows freely to the regulator.If the mixture is too lean: lower the internal diameter of the mixer. Increase the number of holes in the mixer.Loosen the plastic screw on the regulator (to strengthen). Be careful to ensure that the vehicle is idling - it is possible to compensate during idling by completely tightening the idle nozzle.

Before turning orange, a long period of red. – mixture too rich:

Control manifold – air filter, possible obstructions (backfire-protect valve before mixing, wind pressure shield, etc.).If the mix is too rich: increase the internal diameter of mixer, lower the number of holes in the mixer.Tighten the plastic screw on the regulator (to weaken). Be careful to ensure that the vehicle is idling - it is possible to compensate during idling by completely tightening the idle nozzle. The idle nozzle doesn’t influence higher RPM.

4.3           Phase 2 - idling

Indicators are continually lit orange after the idling RPM test.

When idling, the unit doesn’t change from red to green.

Under normal running conditions, (after the autotest), we set the idling rate with the help of an adjusting plastic screw and idle nozzle so that the indicators blink lean / rich. Strengthening the idle nozzle or adjusting the screw weakens the idling mixture - should result in flashing green indicators. Loosening (when the green LED is lit) enriches the idling mixture - should result in flashing red indicators.Reset the unit and repeat the autotest.

5. Basic Information about Interfacing the “Tronic” Unit to PC.

To connect to PC, it is essential to purchase the Lovtec Tronic interface (code 4201).

Minimum computer configuration:    PC 486, 8M RAM, 200M HDD,Windows 95 or higher.

Set up: the factory settings program is on COM1 and it is possible to change it to COM 2 in the second line of the file tester.ini. For slower computers (Pentium 120 and lower) it is important to change the screen to 8 colours.

While connecting the computer to the CU (Control Unit) through the interface (code 4201), connection is automatic. The current values of Lambda and TPS are read, as well as the position of the stepper motor, if the unit is hooked up to a +12V battery, and the computer is set to the right COM, with the application program running. See below. Changes in TPS voltage will not be shown until the key has been turned, because the gasoline-control unit will not have been activated. (Some vehicles also connect to TPS only after start up). Lambda changes are shown after the engine is restarted.

Updates on the status, and the parameters of the unit and fuel diagnostics are always available by clicking on the “Read from CU” (Control Unit) button.

Results are shown on the monitor of your computer. The unit operates according to the parameters you set, at the moment when  the parameters are sent to the Control Unit. You must click on “Send to CU”.

Results are saved to permanent memory after switching back to gasoline, or by clicking on “RAM =>EEPROM”.

Autotest will not operate if the PC has been connected to the CU and the “RAM =>EEPROM” button has been pressed, before the LPG has been turned on.

Read from the CU, and follow changes in status in the "StaCU" box.  Autotest is able to bypass current red (+12Vbat.) and blue (+12V LPG) wires when the unit is first connected to the power source.

Resetting the unit so that it will carry out an autotest can be done by clicking on the “Factory Reset” button, only if the unit is not switched to LPG. If it is on LPG, only factory settings for control will be activated.

Changes in the “Starting Position” of the stepper motor and “Lambda Ignore Time” take place only when they are saved to EEPROM with the “RAM =>EEPROM” button. This holds true for editing all settings in gasoline mode, so that they will not be written over with old information from EEPROM. Before switching to LPG, the “RAM =>EEPROM” button must be clicked.

All data besides the actual voltage of the Lambda and TPS as well as the position of the stepper motor, can be updated by clicking “Read from CU”.

To change among windows, use the following keyboard shortcuts: Ctrl + A (Actual Values), Ctrl + T (Tune CU), Ctrl + S (Save and Read from PC), or arrows, when it is highlighted, or the left mouse button.

Movement in editing TAB on one side,  Shift + TAB on the other side, or with a mouse.

Confirm entry by hitting ENTER or the Space Bar, or by left-clicking the mouse.

“Tuning” and “Actual” Panels – access through keyboard shortcuts  Ctrl L and Ctrl A

Assists in setting up and displaying control parameters. All data are stored in the CU (Control Unit) and then displayed on screen after the “Read from CU” button is clicked. During the establishment of individual borders and speeds, it is important to count on the fact that the unit will act in accordance with the new parameters only after they have been entered into the CU. This can be done either individually by clicking “Save”, or by batch  by clicking “Send to CU” (sends the entire table) which saves the data to RAM. RAM is only temporary memory, and if the unit’s 12V power source is cut, the data is lost. The unit starts up again with the original data last saved in the EEPROM (permanent memory).

 “Lambda Limit”: parameter representing the Lambda change from lean to rich. The standard, factory set Lambda is 0,2 – 1,2V and it is not recommended to change this. Change is advantageous when Lambda settings are 0,4-1,6V, with the higher values creating a middle area where Lambda can move. One step = 0,02V.

“Lambda Ignore Time”: is the amount of time, in seconds, after which the signal from the Lambda sensor (switched to LPG) will be ignored. The stepper motor is set in the “Starting Position”.

The “RAM=>EEPROM” button immediately saves the set parameters into EEPROM (permanent memory) This always takes place after switching from LPG to gasoline. It is possible to disconnect the unit from its power source, and the data stored in EEPROM will remain saved.

The “EEPROM=>RAM” button transfers data from the permanent memory to temporary memory (RAM). It is advantageous when you are starting up a new project to use the last saved parameters.

"Actual”: This field displays the current position of the stepper motor and Lambda settings, as well as TPS, both numerically and graphically, with highlighted transitional limits. The same values are displayed across the entire “Actual” panel. This panel serves to simplify watching the values from a distance. For example, during mechanical tuning of the vehicle.

1.TPS limit: is reached in the transition from idling to the so-called “leaner zone” of increased RPM.

2.TPS limit: is reached in the transition between the leaner zone and high output.

3.TPS limit: upon reaching this limit, the motor is running with a maximally open throttle, and maximum performance.

Each limit can be very precisely attained by using the autotest, as long as the TPS is properly connected.

Position “Max”: in individual zones, the established upper limit of the open stepper motor.

Position “Min”: in individual zones, the established lower limit of the open stepper motor.

Both of these borders are important for solving transitional phenomena.

When the stepper motor stays at a given limit for more than 40 seconds, a memory error will occur, and cause a reading error. See “On Board Diagnostics”.

Autotest creates a limit for idling and the first and second zones of increased RPM. Optimally, the limits are established after an autotest at around forty steps, and with the same values of ±10 steps.

Speed “UP”: is the speed of the stepper motor when opening. Increasing this speed enriches the mixture, the  level of NOx decreases and the level of CO2 increases.

Speed “DN” ”: is the speed of the stepper motor when closing. Increasing this speed enriches the mixture, the level of CO2 decreases and the level of NOx increases.

NOTE: The factory settings are a compromise. For specific vehicle types, we recommend using the speed and configuration file available on line at: www.hlpropan.cz . For those types not listed, we recommend the following:

Remember: the lower the performance, the lower the speed; the longer the engine manifold, the lower the speed.  Too high a speed indicates a pulsating operation of the engine, dependent on the mixture of lean / rich, and the large control range, increasing all harmful exhaust fumes in their stabile stage. Too low a speed results in an increase in harmful exhaust fumes in the transitional stage. For testing institutes, it is recommended to set the Lambda value to around 0.998 according to the emission tester, in other words, slightly richer.

Status Variables in the Lower Panel

StaCU = Unit status

Indicates in which order the unit will flash in its start-up sequence. The colours are always expressed by two bits, from the left .

For example, a new unit before conducting an autotest, or after resetting with gasoline. See 3. LED Signals During Start Up.

StaTPS=

StaLam=

“Service” Panel - enter with the keyboard shortcut Ctrl S

Communication software allows the creation of databases with the specific parameters of a given vehicle. The "Service Panel" helps. Reading the parameters from the database of the computer “Tuning panel” is done by clicking on the “Read from File” button and the choice of application files. The parameters are then transferred from the file to the “Tuning Panel” on your PC. This data  is then transferred from the “Tuning Panel” to the Control Unit by clicking on “Send to CU”. We recommend backing up the information in the CU by resending it to the PC. The unit begins to adhere to the parameters from the moment it begins receiving data from the PC.By clicking on “Save as” a dialogue box comes up requesting a name for your new file and stores it in the database.

“Lambda / TPS Status” panel

This panel is clear, until the “Read from CU” button is clicked from the “Tuning” panel on the main menu. The group “Type of Lambda Emulation”: in this group, where you can select boxes, the choice of Lambda sensors is made for the gasoline control unit, and if needed, the kind of signal.

“Open Circuit”: In this setting, the signal from the Lambda sensor doesn’t move on to the gasoline control unit. The gasoline controlled unit understands this as an error, and sets up an alternative control. Using this setting is advantageous in vehicles able to run normally, after being switched from LPG to gasoline (gasoline emissions are in order).

“T Lambda”: here, the Lambda signal is delivered to both control units. This setting is advantageous in cases where the speed controls on LPG (transition from lean-rich) are similar to those with gasoline. A disadvantage is in cases with an LPG of  a leaner mixture (fuel runs out), the gasoline control unit extends the length of the injection, in order to enrich the mixture, without influencing the operation of LPG to the corresponding response. The following operation using gasoline will be rich, until the old parameters are readapted. This system is not recommended  for long manifolds. – low speed control.

“Single Zone Emulation”: This setting during LPG operation generates frequent Lambda changes for the gasoline unit regardless of the real control status. To be more exact, the Tronic unit is equipped with a measuring level and speed signal, that will be generated. This is carried out by the “Idling Emulation Measurement” button, while the engine is idling on gasoline. The unit indicates measuring status on the computer.  After measuring, the entries for “Rich Idle Time” and “Lean Idle Time” are automatically renewed. The unit generates a constant idling signal for all TPS positions. After ompleting the measurement process, it is important to save the data to EEPROM.

“Higher Idling Emulation” This setting during LPG operation generates frequent Lambda changes for the gasoline unit regardless of the real control status. It is similar to the previous setting, with the difference that two gasoline measurements must be carried out. The second measurement, the “Higher Emulation Measurement”, must be made at around 3500 RPM, by clicking the same button as in the previous example. The unit then generates two signals (idling and higher RPM) according to TPS (the limit of the emulation changes is “2.TPS limit”). After making changes, it is important to save the results in EEPROM.

Speeds are freely editable in their respective boxes.  The unit parameter is  0,05sec.

Group “Type of Lambda Voltage”: Here, the Lambda type is set. The factory setting is 0-1,2V.

Group “Type of Lambda Logic”: Here, the Lambda logic is set (normal or inverted). The standard is 1,2V = rich mixture – normal logic.

Group “TPS Logic”: This is for setting up TPS. If a voltage increases with acceleration, then it is rising.

If it lowers, then it is decreasing. A proper box is set after a properly completed autotest.

 “On Board Diagnostics” Panel

This panel is clear until the “Read Diagnostics” button is clicked. Entries are made individually, and the computer merely displays them.

The first row of this panel provides manufacturing information concerning unit type and production date. In the second row, in the “Total Work” field, when connected to +12V battery, the time in the form month/day/hours: minutes is read. In the “Work on LPG” field, time is read only when LPG is running. The one editable panel, “Tacho Status” contains information that was saved during the last installation or regular servicing.

 “Last Servicing” indicates the date when the computer was last used to service (by clicking on the “Completed Service” button, in the form of day/month/year.

 “Service Number” is the number assigned to the software on the PC when bought.The number is put on the product warranty of Lovtec Tronic Interface (code 4201).

Group “Errors”: in this group, when an error has been made, a number is displayed to signify the error status. The error status occurs when the unit is not able to control the mixture.  Errors are divided into TPS and Types of Mixture. For example, a set up error (lean idle) will be displayed in the field as “Lean Idle Error”, which will be read after an interval of about one minute. The stepper motor remains at the upper limit, the indicators are continually green.

 Errors can help identify mistakes even during tuning up of the vehicle. Errors won’t be read, if the limits are set too wide. Errors have no influence on the operation of the unit, they merely identify a status where the stepper motor stops at a given limit.

To erase the error memory of the unit, click on the “Erase error memory” button.   The  mistake is shown on the display until the “Read Diagnostics” button is clicked again.

Copyright © 2000  HL Propan s.r.o.
Last change: 11.03.2008