3T5-76022-0 Tohatsu CAP, MAIN SWITCH

Illustration 1 g01141323
Schematic of the electronic control system
(1) Fuel injection pump
(2) Voltage Load-dump Protection Module (VLPM)
(3) Service tool connector
(4) Electronic Control Module (ECM)
(5) Machine interface connector
(6) Timing wheel
(7) Primary speed/timing sensor
(8) Intake manifold pressure sensor
(9) Coolant temperature sensor
(10) Engine oil pressure sensor
(11) Intake manifold temperature sensor The electronic control system for the 3054E engine has the following components:
Electronic Control Module (ECM)
Pressure sensors
Temperature sensors
Primary speed/timing sensor
Voltage Load-dump Protection Module (VLPM)Electronic Control Module (ECM)
Illustration 2 g01133234
Electronic control module (ECM)
The ECM functions as the governor and the computer for the fuel system . The ECM receives all the signals from the sensors in order to control the timing and the engine speed.Reprogramming of the ECM requires factory passwords. Passwords are used in the "ECM" for the following reasons:
Prevent reprogramming that is unauthorized.
Prevent erasing of logged events that is unauthorized.
Allow the customer to control certain programmable engine parameters.The factory passwords restrict changes to authorized personnel. Factory passwords are required to clear any event code. Refer to Troubleshooting, RENR2417, "Factory Passwords" for more information on the passwords.The ECM has an excellent record of reliability. Any problems in the system are most likely to be the connectors and the wiring harness. The ECM should be the last item in troubleshooting the engine.The personality module contains the software with all the fuel setting information. The information determines the engine performance. The personality module is installed behind the access panel on the ECM.Flash programming is the method of programming or updating the personality module. Refer to Troubleshooting, RENR2417, "Flash Programming " for the instructions on the flash programming of the personality module.The ECM is sealed and the ECM needs no routine adjustment or maintenance.Pressure Sensors
Illustration 3 g00884730
Intake manifold pressure sensor
The intake manifold pressure sensor is a three-wire active sensor that is supplied with power from the ECM. The sensor provides the ECM with a measurement of intake manifold pressure in order to control the air/fuel ratio. This will reduce the engine smoke during transient conditions. The intake manifold pressure sensor is also used for engine monitoring.The operating range for the intake manifold pressure sensor ... 55 kPa to 339 kPa (8 psi to 50 psi)Required accuracy ... 3% of maximum pressure
Illustration 4 g01133306
Engine oil pressure sensor
(1) Sensor common
(2) 5 volt supply
(3) Pressure signal The engine oil pressure sensor is also an active sensor with three wires and a power supply. The sensor provides the ECM with a measurement of engine oil pressure. The ECM can warn the operator of possible conditions that can damage the engine. This includes the detection of a blocked oil filter.The operating range for the engine oil pressure sensor ... 110 to 882 kPa (16 to 128 psi)Required accuracy ... 3% of maximum pressureTemperature Sensors
Illustration 5 g01133312
Temperature sensor
(1) Negative terminal
(2) Positive terminal The intake manifold temperature sensor and the coolant temperature sensor are two-wire passive sensors. The intake manifold temperature sensor provides the ECM with intake manifold air temperature so that the ECM can control the fuel for starting and injection timing. The coolant temperature sensor provides the ECM with coolant temperature so that the ECM can control injection timing. The temperature sensors are also used for engine monitoring.The operating range for the temperature sensors ... −40° to 150°C (−40° to 302°F)Required accuracy for sensor ... 1 °C ( 1.8 °F)Primary Speed/Timing Sensor
Illustration 6 g01133334
Primary speed/timing sensor
(1) Negative terminal
(2) Positive terminal The primary speed/timing sensor is also a two-wire passive sensor. The sensor provides the ECM with the speed and the position of the engine from a timing wheel that is mounted on the crankshaft so that the ECM can control fuel and timing from the fuel injection pump. The timing wheel has one missing tooth that is located 70 degrees after top center.The operating range for the primary speed/timing sensor ... 142 to 3333 RPMWhen the engine is cranking, the ECM uses the signal from the secondary speed/timing sensor in the fuel injection pump. When the engine is running, the ECM uses the signal from the primary speed/timing sensor on the crankshaft. This speed/timing sensor is the primary source of the engine position.Note: If the primary speed/timing sensor fails, the engine will be derated and the engine will continue to operate on the secondary speed/timing sensor. Refer to Troubleshooting, RENR2417 for more information.Voltage Load-dump Protection Module (VLPM)
Illustration 7 g01133354
(1) VLPM The VLPM monitors the voltage of the system and the VLPM will protect the ECU on the fuel injection pump against voltage spikes and reverse polarity. The fuel injection pump will be shutdown if there is high voltage on the system.