Chris' '90 Toyota Celica All-Trac Turbo (aka "The Shuttle")
Autronic SMC Documentation

The software utility supplied with Autronic SMC ECU may be used with any IBM compatible computer that in operating under MS-DOS 3.0 or later.  The computer must have the following hardware: an MDA, CGA, EGA or VGA graphics adaptor,  128K RAM, one RS232C serial port, and one 3.5" floppy drive.  

The following functions are available using this program: 

• Real-time display of the current operating status of the ECU and engine
• Display of error/fault condition history information recorded in the ECU and the cancellation of stored error history.
• Display of the relative timing of the engine position reference signals for ease of setup.

Calibration adjustment:

• Non-interactive calibration of the ECU. (Off-line calibration editing).
• Interactive calibration of the ECU (online calibration editing).
• Disk file storage and retrieval of calibrations.
• Free transfer of calibrations between file, screen and ECU.
• Calibration process does not effect normal ECU operation i.e.:- No hiccups during online adjustment.
• Calibration may be password secured in ECU to prevent unauthorized access.
• User I.D. may be included with calibration in ECU for ease of future identification.

The calibration features accessible with this version of the program are as listed below.  All tabular calibrations may have a user selected table size from 1 X 1 = 1 variable up to the maximum specified for each table. The program allows calibration tables (or maps) to be defined with variable spacing of the calibration grid points. Mapping detail can be fine where engine characteristics vary dramatically and course where engine characteristics are well behaved. This ensures that precise calibration is achieved with a minimum of effort. Variable mapping precision if achieved by allowing arbitrary choice of the calibration axis site values. The program allows the building of larger tables by the insertion of table rows and for columns, as more calibration detail is required.  Calibrations, other than the base fuel and ignition tables, may-be initialized with default values to eliminate the complexity of these enhanced features in applications where only the basic features are required.

Basic fuel delivery calibration table providing fine (0.1%) adjustment of fuel.  This table, the engine "load", barometric pressure and corrections dependent upon intake and coolant temperature, acceleration and deceleration and external trims determine the actual rate of fuel delivery for all engine operating conditions.  The table data values being a representation of the engines "Volumetric efficiency" allows considerable simplification of the calibration procedure. Up to 32 engine speed and 16 engine load dependent calibration sites may be chosen at random calibration intervals giving up to 512 adjustment points. The engine load variable used in this table and others that follow below is a function of throttle position if throttle position is chosen as the primary input and a function of manifold absolute pressure if pressure is the primary input.

Basic ignition timing calibration table for "normal" engine operation, excluding cranking, idling and over-run conditions. The table uses the same site calibrations as the base fuel delivery table and therefore is of equal size. Timing is selectable in 0.25 Degrees increments over a range from 0 to 50 Degrees crank angle. The calibration from this table is combined with temperature dependent corrections and. an external trim to produce the actual engine "running" ignition timing.

Engine speed dependent ignition timing calibration for stable combustion under closed throttle conditions. The adjustment range is the same as the base ignition timing calibration table above. The table comprises a single row using the same engine speed calibration sites as the base fuel delivery table above.

Ignition timing for engine cranking calibration allows the selection of an engine speed dependent timing characteristic that minimizes the possibility of starting gear damage due to engine kick-tack yet aids in the rapid acceleration of the engine up to running speed. The range of calibration is as for the bass ignition table and up to 5 engine speed calibration sites may be chosen.

Idling ignition timing calibration allows optimal timing during this condition for good idle quality and improved idle speed stability. The range of calibration is as for the base ignition table and up to 5 engine speed calibration sites may be chosen.  

Base ignition timing modification dependent upon engine coolant temperature and engine load to ensure efficient operation during warm-up and to minimize the possibility of engine damage if over-heating occurs. Table size is 12 engine coolant temperature calibration sites by 6 engine load calibration sites and the correction range is +/-31.75
degrees.

Base ignition timing modification, dependent upon barometric pressure and engine load to ensure efficient operation at high altitude. Table size is 7 engine load calibration sites by 2 barometric pressure calibration sites and the correction range is +/- 31.75 degrees.

Calibration of the actual positioning of the fuel injection pulse within the engine cycle, dependent upon engine speed and engine load. Calibration may be selected at up to 20 engine speed sites and 5 engine load sites with a resolution of 2.8 crankshaft degrees.

Individual calibration trim tables for each injection group (i.e.:- cylinder) to correct for injector calibration differences or individual cylinder efficiency differences due to non-ideal manifolding. These tables share common calibrations sites with the injection timing calibration data (20 X 5) and allow +/- 61% adjustment range in 0.4% increments.

Calibration table that allows the throttle position sensor to act as a back-up in the event of a pressure sensor failure, thus ensuring almost normal engine operation.  This is used for limp home in applications where pressure is the primary engine load input.  This table can have up to 8 engine speed calibration sites and 6 throttle position calibration sites.  Calibration range is 20 to 420 KPa in 0.1 KPa increments.

Calibration table that provides a limp-home function if the throttle position sensor is faulty. This table uses the same engine speed calibration sites as the manifold pressure failure table limp-home table. Calibration range is 0 to 100% in 0.1 % increments.

Calibrations to optimize the operation of the engine during- acceleration and deceleration. These calibrations all have common engine speed calibration sites (up to 8 max).

This calibration allows estimation of the amount of heat transferred to the incoming charge by the hot manifold and intake port, so that an actual charge temperature may be estimated for the calculation of correct fuel delivery.  This table can have up to 16 engine speed calibration sites and 10 engine "load" calibration sites.  The calibration represents % contribution that coolant temperature has in determining the charge temperature, its range is 0 to 100% in 0.5% increments.  This calibration is particularly useful for two-stroke engines where the charge temperature is almost totally determined by crankcase temperature.

This calibration table allows engine coolant temperature and engine "load" dependent control of additional fuel delivery.  It controls additional fuel delivery after the initial post start enrichment period has finished, and its function is to ensure stable engine operation during engine warm-up.  It can also be used to enrich the air/fuel mixture at high engine loads if an engine overheated condition is detected in order to minimize the risk of engine damage.  Calibration may be selected at up to 13 engine coolant temperature sites and 10 engine "load" sites and the adjustment range is 1.00 to 1.99 times the base fuel delivery.

Additional fuel delivery immediately after start-up is controlled by this table, this additional delivery decays away with time to the warm-up enrichment value from the table above. The calibration range is 1.00 to 3.99 times the base fuel delivery.  This calibration function is only engine coolant temperature dependent and it uses the same engine coolant temperature 'calibration sites as chosen for the warm-up enrichment calibration table.

The decay time for the additional fuel delivery immediately after start-up is controlled by this table.  The calibration range is 0 to 20 SEC.  This calibration function is only engine coolant temperature dependent and it uses the same engine coolant temperature calibration sites as chosen for the warm up enrichment calibration table.

Calibration multiplier for additional engine coolant temperature dependent acceleration enrichment.  The calibration range is 1.0 to 8.0 times the "warm" engine value.  This calibration uses the same engine coolant temperature calibration sites as chosen for the warm-up enrichment calibration table.

Calibration for idle speed increase required of automatic idle speed control function during low temperature engine operation.  This calibration table may also be used to increase the idle speed if engine overheating occurs so that engine driven cooling fan efficiency is improved helping to elevate the condition.  The calibration range is 0 to 1020 RPM.  This calibration uses the same engine coolant temperature calibration sites as chosen for the warm-up enrichment calibration table.

Calibration for idle speed increase immediately following start-up.  This effect decays away with time to warm-up fast idle RPM calibration.  Calibration range is O to 1020 RPM.  This calibration uses the same engine coolant temperature calibration sites as chosen for the warm up enrichment calibration table.

Decay time for post start fast idle increase. Calibration range is 0 to 41 SEC.  This calibration uses the same engine coolant temperature calibration sites as chosen for the warm-up enrichment calibration table.

Boost Control Calibration Tables - One turbocharger wastegate control calibration table is available.  The table allows engine speed and engine coolant temperature dependent setting of the boost level controlled by the boost control function.  The coolant temperature dependency of the table (if used) allows boost to be, reduced at elevated engine coolant temperatures in order to minimize the possibility of engine damage.  The table can have up to 10 engine speed calibration sites and 5 engine coolant temperature calibration sites.  The calibration range is 110 to 500 KPa.

Boost Control Throttle Modifier Calibration - The boost level determined by the above calibration table may be made throttle position dependent by setting this table to effect a reduction in boost under conditions less than full throttle. The table may have up to 4 throttle position dependent calibration sites and the range for calibration is 0 to 300KPa.

Engine rev limiting may be made coolant temperature dependent with this table.  A maximum of six engine coolant temperature calibration sites may be selected.  The calibrations may be selected in the range 0 to 30000 RPM in 1 RPM increments.  Additional control variables allow the characteristics of the rev limiter function to be tailored for the application.

Two engine coolant temperature dependent engine speed calibrations may be defined, one specifies the minimum engine speed that fuel delivery shutoff can commence under trailing throttle conditions and the other the minimum engine speed down to which fuel shutoff will be sustained.  Higher engine speeds can be selected during engine warm-up to minimize the drivability problems associated with fuel delivery shutoff.  The engine coolant temperature calibration sites chosen for the engine speed limit calibration function are also used by this function.  The calibrations may be selected in the range 0 to 30000 RPM in 1 RPM increments.

Base idle speed calibration adjustment to provide the idle speed steeping for the automatic idle stabilization function.  This table allows battery voltage dependent idle speed selection if desired.  It also helps ensure battery charge is tained under all conditions.  A maximum of three battery voltage calibration sites may be selected.  The calibrations may be selected in the range 300 to 5000 RPM in 1 RPM increments.

This user-defined table is a 16 by 10 table that allows the user to define the output-characteristics of a spare pulse width modulated output as a function of any 2 variables that the ECU measures.  A typical application would be the control of the actuation of an auxiliary upstream butterfly (a la Toyota T-VIS) depending upon throttle position and engine speed in a turbocharged application in order to minimize turbocharger lag.

This user defined table is a 6 by 4 table that allow the user to define the on /off characteristics of a spare relay output as a function of any 2 variables that the ECU measures.  A typical application would be to control activation of a nitrous system.

The idle mixture trim screwdriver adjustment can be configured to operate over any defined engine speed and load range with up to +/- 25% of adjustment range.  This allows the control to suit road and race tuned engines and also allows the action of the control to be inhibited if government authority regulations exclude any idle mixture adjustment.  The calibration may be selected at up to 2 engine speed sites and 2 engine load sites with an adjustment range of 0 to +/- 25% in 0.1% increments.

This calibration table allows the ECU to estimate barometric pressure at times other than before engine start-up using the internal MAP sensor.  The table may have a maximum of three engine speed calibration sites and six throttle position sites.  The calibration range is 0 to 50 KPa IN 0.2 KPa increments.

This 16 by 10 calibration table is for use in applications where closed loop air fuel ratio operation is required. 

The throttle position sensor (TPS) should be mounted directly on the throttle, shaft or alternately connected to this shaft a rigid lash free linkage.  Either a linear or rotary type potentiometer sensor may be used.  Its electrical resistance should be in the range 2000 to 20,000 OHMS.  Movement of the throttle over its full travel must not stroke the sensor to its limits of mechanical travel, otherwise damage to the sensor may result.  Mounting and/or linkage construction must be such that the travel is always less that the total available electrical travel.  The electrical connections to the two ends of the potentiometer (fixed terminals) must be chosen so that the output voltage increases with increasing throttle opening.  If the reverse occurs then the two end terminal connections should be interchanged.  A voltmeter should be used to check the output voltages at the extremes of travel.  Ideally the sensor should be mounted so that the throttle closed output voltage should be between 0.5 and 0.6 volts.

The following conditions MUST be met:

• Throttle is fully closed the output voltage MUST be in the range 0.4 volts to 1.8 Volts.
• Throttle fully open the output voltage MUST be in the range 3.2 to 4.7 volts. 
• The difference between the voltage at the extremes of travel should be greater than 2.5 volts.
• The voltage should increase smoothly with increasing throttle opening, there should be no dead spots in the total throttle travel.

The ECU is equipped with an automatic adaptive learning function that simplifies the procedure of throttle position sensing.  Setup is much simplified, not requiring any diagnostic aid, calibrator or laptop computer.  The procedure is as follows:

• Ignition switch on, engine stopped.
• Disconnect throttle position electrical connector for at least 5 seconds.
• Reconnect throttle position electrical connector.
• Ensure that throttle is closed for at least 5 seconds.
• Fully open the throttle for at least 5 seconds.

The above procedure records the limits of throttle travel in the ECU.  Additional ECU functions ensure that throttle stop and sensor wear are compensated for over the life of the engine.  The above procedure need only be repeated if the butterfly / sensor assembly is serviced or replaced.

Many variables exist that work with the above calibration functions, some are selected automatically by the laptop program depending upon the users response to questions asked by the program, others may be adjusted directly from a special screen display.  These calibrations include: number of engine cylinders, compression ratio, selection of two or four-stroke engine, selectionof MAP or TPS as engine load input, overboost protection, as well as..

• Overall Fuel Delivery Multiplier - Provides correct scaling for all fuel delivery tables and allows changes to injector sizing and/or fuel pressure without having to re-calibrate the fuel delivery tables.
• Injection Response Compensation -  Selects the correct response characteristics for all commonly available injectors.
• Acceleration Enrichment -  Throttle sensitivity and maximum acceleration fuel delivery allow trimming of the minimum and maximum limits of enrichment.
• Cooling Fan Control Adjustments - Allows co-ordination of two cooling fans according to vehicle speed, engine coolant
  temperature and air conditioner operation.
• Automatic Idle Speed Stabilization Control Adjustment - Allows the trimming of the control characteristics of the idle stabilization function for optimal operation.  The supplied default values are normally ok. 

The ECU’s red LED indicator flashes error codes to indicate fault conditions.  Error conditions include: faulty sensors. out of range signals, electrical interference, Operation endangering engine life, and internal ECU malfunction.  This indicator is located near the connector, and connection of a remote indicator light is available.  Each time the ECU is activated (ignition on) previously detected HISTORY or old error conditions are indicated. After the completion of the HISTORY error codes, error codes are displayed as the errors are detected.  An error code will re stored in ECU memory until the fault is repaired and the engine is warmed-up (from cold to normal operating temperature) 20 times.  This error memory feature allows the engines' user reasonable time to fault find difficult intermittent faults, or drive in limp-home mode to qualified service for repair.  When the repair is effected the old stored error codes may be erased by using the laptop calibration
program.

Return to The Shuttle's Autronic EMS page