Trigger System

Trigger System Configuration


Engine Configuration - Trigger System Page

This section contains setup information for configuring your engines' trigger system, including crank and cam trigger patterns and sensors.

Trigger Configuration

Trigger Type

This is set to the type of trigger system that the ECU is connected to. The Nexus ECU requires this information to know Engine position and RPM, and when fuel and spark events should occur. Most engine manufacturer and types are supported and can be directly selected from the list. For those with custom trigger systems, a Generic Missing Tooth or a Generic Multi-tooth can be selected and the number of teeth entered. If you are using an engine that is not listed, or it uses the same trigger type as another engine type on the list, Haltech can be contacted and you can request your engine type to be added with a future update. Selecting a trigger type displays an information panel that describes the crank and cam sensor patterns, which may be helpful in selecting the correct Trigger Type.

Trigger Signal Location

The location of the Trigger. Enter if the Trigger is located on the crankshaft, or it is located on the cam eg. a distributor. If this setting is grayed out, the ECU already knows this information from the selected Trigger Type.

Number of Teeth

Active only when a Generic Trigger Type is selected. This is the physical number of teeth on the trigger wheel located in the trigger signal location, including any missing teeth as if they were still there. Eg. if you have 35 physical teeth with a gap where one tooth would be, you would enter 36 as the number of teeth. If this setting is grayed out, the ECU already knows this information from the selected Trigger Type.

Number of Missing Teeth

Active only when Generic Missing Tooth is set as the Trigger Type. The number of physical teeth that are missing from the trigger wheel.

TDC Offset Angle

The angle between the trigger tooth for cylinder 1 and TDC for cylinder 1. This value is important to set correctly to ensure timing accuracy. The value can be any number between 0 and 720 degrees (the full engine cycle) that allows the commanded ignition advance and the actual ignition advance to match. Typically it is adjusted while the Ignition Lock Mode is active. A timing light is required to set this value.

TDC Offset Angle Table Enable

Enabling this turns on the TDC Offset Angle Table in your Nexus ECU. The TDC Offset Angle Table allows for fine adjustment where the locked ignition timing advances or retards over RPM, and allows the ignition timing to match between ECU and Crank at all RPM. This may be required due to sensor output delays. For ignition delay compensation, see 'Ignition System > Time Offset'

RPM Filter

Filters the engine RPM value the ECU uses for all calculations. The filter value can be increased to remove excess fluctuations that can make tuning difficult with aggressive engines. Setting a filter value that is too high will cause calculations to lag behind the actual engine speed. Setting a filter value that is too low will cause erratic calculations that do not match the true engine speed. Set the filter to a value that gives a crisp engine rpm trace when viewed in datalogs. This value is the time constant for the RPM value to make a 63% change from the old value to the new one. Default - 3ms.

Quick Start

Enables the quick start feature. When using Direct fire ignition and Sequential injection enabling this function fires the Ignition in Wasted Spark and the Injection in Semi-sequential mode when Engine RPM is under the "Max Cranking RPM" and the ECU has at least Half-Sync information. This will assist with faster engine starting. We recommend disabling this function when using CDI style ignition systems and on Methanol fueled engines. Default - Enable.

Trigger Signal

Sometimes referred to as the Reference, Crank Sensor, or NE signal, the Trigger Signal tells the ECU what RPM the engine is running at. The minimum requirement for the trigger to run an engine is to have one tooth (pickup event) per spark event. There are many different tooth patterns used by different manufacturers. Most of these patterns are supported by your ECU and you simply need to select the correct engine type, allowing the ECU to know what pattern to expect. Some trigger patterns give more information than others. Eg. Missing tooth triggers allow for engine synchronisation giving the Elite ECU the ability to know not only that the engine is turning, but also the position of the crankshaft. Many Trigger patterns also use a Home Signal.

Sensor Type

Required to tell the system which type of sensor is connected to the Trigger input. 

Reluctor

A magnetic analogue sensor. In most cases it can be identified by having only 2 wires although some may have a 3rd shielding connection. It is an unpowered sensor that generates an analogue signal where a positive voltage signal produced as the tooth approaches the sensor, and a negative voltage signal is produced as the tooth moves away from the sensor. Known also as 'Variable Reluctance Sensor', 'VR', 'Reluctor', 'Magnetic', or 'Analog'. These sensors generate a sine wave. When set to reluctor, the ECU will enable the 'Arming Voltage' table for the sensor (see below).

Hall Effect

A digital sensor that generates an on and an off voltage, and directly switches between the two. Hall sensors are powered sensors and as such will have 3 or more wires. These sensors produce what is known as a square-wave digital pattern. Known also as 'Optical' or 'Digital'. These sensors generate a square wave. When set to Hall Effect, the signal has a 1.0v threshold centered around 2.5v. Eg, the signal must pass through 3v then 2v (falling edge) in order for the ECU to accept the signal. 

Custom

Only select this option is instructed to do so by Haltech. This setting allows for unique sensor properties to be supported and requires advanced knowledge to correctly configure.

Edge

Select if the Rising or the Falling edge is to be used as the detected edge by the Trigger. The edges are found through testing and in most cases Haltech can provide the correct settings for your Trigger Type.

Pull Up

Required with a Hall Effect sensor to generate a desired signal voltage. This setting will connect an internal resistor in the Elite ECU between the signal wire and 5V. Reluctor Sensors do not require a pullup.

Disabled

No pull up resistor is used. An external pull up or a sensor with a built in pull up will use this setting. If you are connecting your ECU so that it is sharing a signal with another ECU, such as an OEM ECU, you will select this option. The OEM ECU will have an internal pull up of its own and not require the ECU to have a pull up enabled.

Enabled

An internal 1.2K Ohm resistor will be connected between the signal input and 5V.

Strong

An internal 440 Ohm resistor will be connected between the signal input and 5V.

Ground Reference

Required only when using a reluctor or custom sensor. When enabled, this setting will use the ECU Signal Ground as the 0V reference when measuring voltage from the sensor. This should be used when both the ‘Trigger+’ and ‘Trigger-' wires cannot be run directly to the sensor itself, or when the sensor type requires it. Eg, Trigger + will be wired to one pin of the sensor, and the other pin will be wired to signal ground in the harness.

Home Signal

Sometimes referred to as the Sync, Cam Sensor, or G sensor, the Home Signal allows the ECU to know camshaft position, and therefore crank position over the full 720 degree engine cycle. From this it also knows cylinder position, which in turn allows full sequential operation of the fuel and ignition systems. A single tooth is all that is required for the system to know the engine synchronisation. Some Home Signal patterns contain multiple teeth, which is a requirement for accurate cam position detection with engines that use continuously variable cam timing.

Sensor Type

Required to tell the system which type of sensor is connected to the Trigger input. 

Reluctor

A magnetic analogue sensor. In most cases it can be identified by having only 2 wires although some may have a 3rd shielding connection. It is an unpowered sensor that generates an analogue signal where a positive voltage signal produced as the tooth approaches the sensor, and a negative voltage signal is produced as the tooth moves away from the sensor. Known also as 'Variable Reluctance Sensor', 'VR', 'Reluctor', 'Magnetic', or 'Analog'. These sensors generate a sine wave. When set to reluctor, the ECU will enable the 'Arming Voltage' table for the sensor (see below).

Hall Effect

A digital sensor that generates an on and an off voltage, and directly switches between the two. Hall sensors are powered sensors and as such will have 3 or more wires. These sensors produce what is known as a square-wave digital pattern. Known also as 'Optical' or 'Digital'. These sensors generate a square wave. When set to Hall Effect, the signal has a 1.0v threshold centered around 2.5v. Eg, the signal must pass through 3v then 2v (falling edge) in order for the ECU to accept the signal. 

Custom

Only select this option is instructed to do so by Haltech. This setting allows for unique sensor properties to be supported and requires advanced knowledge to correctly configure.

Edge

Select if the Rising or the Falling edge is to be used as the detected edge by the Trigger. The edges are found through testing and in most cases Haltech can provide the correct settings for your Trigger Type.

Pull Up

Required with a Hall Effect sensor to generate a desired signal voltage. This setting will connect an internal resistor in the Elite ECU between the signal wire and 5V. Reluctor Sensors do not require a pullup.

Disabled

No pull up resistor is used. An external pull up or a sensor with a built in pull up will use this setting. If you are connecting your ECU so that it is sharing a signal with another ECU, such as an OEM ECU, you will select this option. The OEM ECU will have an internal pull up of its own and not require the ECU to have a pull up enabled.

Enabled

An internal 1.2K Ohm resistor will be connected between the signal input and 5V.

Strong

An internal 440 Ohm resistor will be connected between the signal input and 5V.

Ground Reference

Required only when using a reluctor or custom sensor. When enabled, this setting will use the ECU Signal Ground as the 0V reference when measuring voltage from the sensor. This should be used when both the ‘Trigger+’ and ‘Trigger-' wires cannot be run directly to the sensor itself, or when the sensor type requires it. Eg, Trigger + will be wired to one pin of the sensor, and the other pin will be wired to signal ground in the harness.

Minimum RPM

Used with the Quick Start feature enabled, the home signal is ignored below this RPM when determining engine position. While below this RPM, if the Injection Mode is set to Sequential it will operate only as semi sequential, and if the Ignition Mode is set as Direct Fire it will operate as Waste Spark. When RPM goes above this value the home signal is latched on and will help provide more synchronisation information allowing Sequential and Direct Fire operation. This is reset when RPM goes back to 0.

Synchronisation Mode

Selects when the Home sensor should be used.

Always

Always uses the Home signal to determine engine position information, unless RPM is below the Minimum RPM setting and has not yet risen above it (if enabled).

In “Always” synchronisation mode the ECU requires both the Trigger and Home sensors to detect each trigger and home event accurately every engine cycle. A missing Trigger or Home event will result in the ECU losing synchronisation (being unaware of the engine position) and the “Trigger System Error Count” incrementing to let you know there has been a trigger or home error. The ECU will attempt to re-synchronise after the next Home signal is detected. If the “Trigger System Error Count” continues to increment the Trigger and Home signals will need diagnosing to determine the cause of the problem.

Until Full Sync

The home signal gets ignored once the ECU has been at full cycle engine synchronisation for 8 engine cycles, after which only the crank sensor is used for engine position information. This is only available for Generic Standard Full Cycle and some Generic and Missing Tooth and Extra Tooth trigger patterns. This can be used in circumstances where the Home signal is unreliable at moderate engine speeds and loads, such as in very high powered drag applications.

In “Until Full Sync” mode, the ECU will detect the Crank and Cam sensor signals for 8 successful consecutive timed engine cycles then ignore the Home signal and continue to run off the Trigger signal only. This function is only to be used when a reliable Home sensor signal is not available under high engine load/RPM, for example an engine fitted with a high current Magneto ignition system (MSD Pro-Mag or similar). Any missed, extra, or erroneous trigger sensor events will cause an error in the ignition timing, and any subsequent missed crank events will multiply the ignition angle error. Engine damage may occur if these settings are enabled with a faulty or poor Trigger sensor. The Trigger Sensor MUST be functioning correctly with no missing, additional or erroneous trigger signals when using "Until Full Sync" home sensor mode.

Conditional

The home signal gets ignored when the Maximum RPM and Throttle Position values are both met. Full syncronisation is maintained without the home signal. This can be used in circumstances where the Home signal is unreliable at high engine speeds and loads, such as in high powered drag applications. When the Maximum RPM and Throttle Position values are no longer met, the ECU will seamlessly resyncronise by using the Home sensor signal again. This function is only to be used when a reliable Home sensor signal is not available under high engine load/RPM, for example an engine fitted with a high current Magneto ignition system (MSD Pro-Mag or similar). Any missed, extra, or erroneous trigger sensor events will cause an error in the ignition timing, and any subsequent missed crank events will multiply the ignition angle error. Engine damage may occur if these settings are enabled with a faulty or poor Trigger sensor. The Trigger Sensor MUST be functioning correctly with no missing, additional or erroneous trigger signals when using "Conditional" home sensor mode.

Technical Information

Trigger and Home input specifications

-5 to 5V Input
1 Million Samples per Second
Selectable 1k2 or 440R Pullup to 5V
Selectable Ground Reference (Full Differential Standard Mode)
-75 to 75V Indefinite Withstand
48kHz Signal Frequency Max (eg, RB optical home at 15,000 RPM is 45kHz, 60-2 at 20,000 is 20kHz)


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