These inputs are required by the ECU to determine exact crank and cams angles so that spark and injection timing can be calculated.

Crank (TDC)
The crank angle sensor is used by the ECU to determine exact crank degrees as it rotates. This sensor could be situated on the crank or in a distributor or encoder called a CAS. If it is situated on the cam gear like a distributor, then it will have enough pulses for 2 revolutions to represent the crank signal. For example, Toyota uses what we called a 24+TDC pattern. If the sensor is on the crank there will be 12 teeth. If it is on the cam there will be 24 teeth. If a pulse is generated on a 36-1 gear on a crank for example, then the missing tooth is used as a TDC pulse. A TDC pulse represent a signal that comes once every revolution. It is not necessary at TDC of the engine. In a distributor it may have a TDC pulse or Home pulse. If a pulse come once in two revolutions it is called a home pulse.

The crank sensor has a test function. Each firmware file is programmed for a specific sensor pattern. The test function will activate a test procedure of the crank sensor pattern during cranking, to ensure that it is read correctly. If it is incorrect or has the wrong firmware, the software will show errors and not attempt to start the engine. In this mode the ECU will do two revolutions of the crank sensor before starting the engine if the trigger pattern is correct. These Errors have numbers indicating a fault code and description. This is a very useful feature for first time startup after the installation is done. See Setting Crank Sensor Timing below. Note. After setup put the test faction off. It may bother at high RPM’s due to the calculations to determine correct patterns.

Cam (Home)
The cam angle sensor will always be situated on a cam shaft. It could be a lone sensor in the valve cover or in a distributor. This signal only came with later models when full sequential injection was introduced. Some distributors like Nissan and Toyota had both sensors in the distributor. The cam signal will give a unique pattern over two revolutions, allowing the ECU to detect which revolution is the firing stroke. This signal could be one pulse or a number of pulses. The ECU can compare it with the crank signal pattern and determine firing stroke.

This feature is not used in Orion. It can only do open loop VVT cams by setting GP2 value.

Setting Crank Sensor Timing

This block is used to indicate to the ECU where the exact TDC point is on the crank. It works differently for the different style of crank angle sensors. These settings will allow the ECU to synchronize software timing with the actual spark timing on the engine.

On gear type trigger wheels, the Gear Teeth will indicate to the ECU the amount of teeth between the slot and TDC. The Timing Sensor will do finer adjustments to precisely set the timing in-between the teeth.

The example below explains, if you put the engine of a 36-1 trigger wheel on TDC, count the number of teeth from the slot anti clockwise to the pickup sensor plus the one just past the sensor. Put this value in . Then you may adjust the Timing Sensor from 0 to 9 degrees to precisely align the timing light to the tuning software. The example below should work out as Gear teeth 7 Timing Sensor 6 as the last edge of the teeth is in the center of the sensor.

With the engine running match the timing as close as possible by using the Gear teeth setting. For example; the ECU software indicates 10° advance on the real-time bar, but you see 12° advance on the engine. The Timing sensor °BTDC will now be adjusted to accommodate the difference which is 2. With the Timing sensor adjusted the Timing light and the ECU should now be matched.

Important!
When using an Advance / Retard timing light on a wasted spark system the timing light will read double the timing of the engine. So if the timing light reads 20° advance, the actual ignition timing is 10° advance. If you are not sure rather put the timing light on zero degrees and use the pulley marks. Remember that the COP systems are still fired in wasted spark sequence.

On single event triggers you will find that gear teeth are not adjustable only the degrees between the triggers. On a 4Cyl Nissan for example the timing sensor may be adjusted to 180 degrees.