3T9-10080-0 Tohatsu AIR RAIL

Illustration 1 g01045708
Engine speed sensor for the ECMThe engine speed sensor is a powered type of sensor. The sensor receives 10 VDC from the ECM. This voltage is shared with the inlet manifold temperature sensor.The signal from the engine speed sensor varies in voltage and in frequency. The level of the signal varies between 0 VDC and 14 VDC. The frequency of the signal can be measured with the following test equipment:
Oscilloscope
An AC voltmeter that measures the frequency of the signalThe ECM monitors the signal from the engine speed sensor for these faults:523-00 Engine Overspeed - The engine speed is greater than 2000 rpm. The ECM will send a shutdown command to the EIS control module via the Cat data link.523-02 Noisy Engine Speed Signal - The engine rpm is greater than 400 rpm and the ECM has measured an acceleration rate that is greater than 2.5 rpm per millisecond. The engine will continue to run. However, operation of the engine may be degraded.523-11 No Engine Speed Signal - The EIS control measures an engine speed that is greater than 100 rpm. The ECM measures an engine speed that is less than 75 rpm. The ECM will send a shutdown command to the EIS control module via the Cat data link.
Illustration 2 g01045516
Schematic diagram of the engine speed sensorThe engine is equipped with a remote control panel that includes a status control module and air/fuel ratio control.
Illustration 3 g01045514
Schematic diagram of the engine speed sensorThe engine is configured for Canadian Standards Association (CSA). The engine is equipped with an optional remote control panel with air/fuel ratio control.Test Step 1. Inspect the Electrical Connectors and the Wiring
Set the engine control to the OFF/RESET mode. Remove the electrical power from the engine.Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
Thoroughly inspect each of the following connectors:
Connectors for the EIS control module
Connectors for the engine speed sensor
Illustration 4 g01045730
Harness side of the P1 connector (P1-2) 10 VDC for the engine speed sensor (P1-3) Ground for the sensors (P1-31) Engine speed signal
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the engine speed sensor.
Check the harnesses and the wiring for abrasion and for pinch points from the engine speed sensor to the ECM.Expected Result:The connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - The components are not in good condition and/or at least one connection is improper.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. Check for an Open Circuit
Disconnect the following connectors:
J1 connectors for the ECM
Connector for the engine speed sensor
Measure the resistance between the points that are listed in Table 1. During each measurement, wiggle the wires in the harness in order to check for an intermittent problem. Be sure to wiggle the wires near each of the connectors.
Table 1
Resistance Measurements for the Harness for the Engine Speed Sensor    
Terminal on the P1 Connector    Terminal on the Connector for the Engine Speed Sensor    
P1-3 (Ground for the sensors)     B (Ground)    
P1-2 (10 VDC for the engine speed sensor)     A (10 VDC for the engine speed sensor)    
P1-31 (Engine speed signal)     C (Engine speed signal)    Expected Result:Each check of the resistance is less than 5 Ohms.Results:
OK - Each check of the resistance is less than 5 Ohms. The wiring does not have an open circuit. Proceed to Test Step 3.
Not OK - At least one check of the resistance is greater than 5 Ohms. There is an open in the wiring for the engine speed sensor.Repair: Repair the connection and/or the wire, when possible. Replace parts, if necessary. Verify that the problem is resolved.STOPTest Step 3. Check for a Short Circuit
Disconnect the P2 connector.
Measure the resistance between the points that are listed in Table 2. During each measurement, wiggle the wires in the harness in order to check for an intermittent problem. Be sure to wiggle the wires near each of the connectors.
Table 2
Resistance Measurements for the Engine Speed Sensor    
Terminals on the P1 Connector    
P1-2 (10 VDC for the engine speed sensor)     All of the remaining terminals on the P1 connector    
The housing for the P1 connector
All of the terminals on the P2 connector
The housing for the P2 connector
P1-31 (Engine speed signal)     All of the remaining terminals on the P1 connector    
The housing for the P1 connector
All of the terminals on the P2 connector
The housing for the P2 connector Expected Result:Each check of the resistance is greater than 5 Ohms.Results:
OK - Each check of the resistance is greater than 5 Ohms. The wiring does not have a short circuit. Proceed to Test Step 4.
Not OK - At least one check of the resistance is less than 5 Ohms. The wiring for the engine speed sensor has a short circuit.Repair: Repair the connection and/or the wire, when possible. Replace parts, if necessary. Verify that the original problem is resolved.STOPTest Step 4. Check the Installation of the Engine Speed Sensor
Mark the installation of the engine speed sensor.
Loosen the locknut for the sensor.
Rotate the sensor clockwise until the sensor contacts a tooth of the flywheel. Note the number of turns that are required in order for the sensor to contact the teeth of the tooth.Expected Result:At least one half of a turn is required in order for the sensor to contact a tooth of the flywheel. No more than three quarters of a turn are required in order for the sensor to contact a tooth of the flywheel.Results:
OK - The gap for the sensor was correct. Proceed to Test Step 5.
Not OK - The gap for the sensor was not correct. Proceed to Test Step 5.Test Step 5. Inspect the Engine Speed Sensor
Remove the engine speed sensor fro