Wiring diagrams for SECU-3 units (examples)
Synchronization from a Hall sensor, using a high-voltage distributor:
Synchronization from VR CKP sensor, using high-voltage distributor:
Synchronization from VR CKP sensor, Wasted Spark configuration:
Injection on the 1-cylinder engine:
Injection on the 4-cylinder engine:
If one wants to use above example scheme for engines with more cylinders, then second injector driver and more injectors should be added.
Wasted spark, synchronization from VR CKP sensor(s). Description of external connector pins see here.
Synchronization from VR CKP sensor(s), Hi-voltage distributor. Second ignition channal is free in this configuration and can be used for other purposes, for instance to output pulses for low or high voltage tachometer.
Synchronization from a Hall sensor, using Hi-voltage distributor:
How to connect stepper motor driver unit to the SECU-3 Lite:
Examples of wiring diagrams for legacy 24-pin units are here
Wiring diagram of the SECU-3T, synchronization of Hall sensor in distributor.
This is the easiest way to connecting the unit.
It is desirable to install coolant temperature sensor for temperature correction of ignition timing.
It is also possible to connect additional auxiliary units. For example, a stepper motor control unit (for air choke control or IAC), speed control unit of the cooling fan etc.
Synchronization from one VR CKP sensor, “wasted spark”:
Synchronization from VR CKP sensor, wasted spark, using 2-channel igniter (produced in Russia):
Following wiring shows how to connect ignition modules (igniters) and coils for full sequential ignition on 4-cylinder engine. The rest is like on previously shown wiring diagrams.
Synchronization from two VR CKP sensors (using non-missing tooth wheel), “wasted spark”:
Example of connecting BIP373 and coils for Wasted Spark configuration on 6-cylinder engine:
Example of connecting BIP373 and coils for Wasted Spark configuration on 8-cylinder engine:
Example of connecting BIP373 and coils (COP) for sequential ignition on 6-cylinder engine:
Full-sequential ignition on the 8 cylinder engine:
Central (throttle-body) injection or simultaneous injection, one Lo-z or several Hi-z injectors. P&H injector + PWM IAC control unit is used.
Example of single-point injection for engines with 1 or 2 throttle units. Stepper IAC, wasted spark. SECU-2P&H+STEP is used for driving of injectors and stepper IAC.
Example of semi-sequential injection on the 6-cylinder engine, Hi-z injectors, stepper IAC actuator. Two hi-z injector driver boards and stepper motor control unit are used. Three ignition channels of the ECU are reserved for wasted spark.
Example of full sequential injection on the 6-cylinder engine, Hi-z injectors, stepper IAC actuator. Two hi-z injector driver boards and stepper motor driver board are used. High voltage distributor used for ignition.
Semi-sequential injection on the 8-cylinder engine, Hi-z injectors, stepper IAC actuator. Two hi-z injector driver boards and stepper motor control unit are used. Four ignition channels of the ECU are reserved for wasted spark.
Next wiring diagram shows example of full sequential injection on the 5-cylinder engine. Spark is distributed using high voltage distributor. Synchronization from CKP+cam sensors. In this wiring control of stepper IAC is shown.
One more wiring example for 5-cylinder engine. Full sequential ignition, simultaneous injection, stepper IAC. Also, this wiring shows usage of compact ignition, injection and stepper drivers (SECU-IGN-DRV4, SECU-INJ-DRV4, SECU-DRV8825).
Often used sensors and accessories and their part numbers please see on this page.
Description of the parts which shown on diagrams:
- Idle cut-off valve, installed on carburetor.
- Starter blocking relay.
- 3.0 Ampere fuse.
- Power valve, has to be installed manually on the carburetor thus replacing old spring and diaphragm.
- ‘Check Engine’ lamp, 12V and no more than 5W.
- Cooling fan’s relay.
- Twin ignition coil
- Twin ignition coil
- Carburator’s limit switch.
- Crankshaft position sensor
- MAP sensor, for instance, MPX4250, Bosch 0 261 230 004 or other.
- Coolant temperature sensor
- Camshaft position sensor
- Knock sensor, for instance Bosch 0 261 231 176.
- Crankshaft position sensor (additional)
- TPS – Throttle position sensor
- IAT – Intake air temperature sensor
- Narrow band oxygen sensor
- 4-channel hi-z injectors’ driver
- Stepper motor control unit (like L297+L298)
- Fuel injectors (Hi-z)
- IAC actuator (stepper or PWM)
- Fuel pump relay
- P&H injector + PWM IAC control unit
- P&H injector and stepper IAC driver unit