334-00131-0 Tohatsu KEY, MAGNETO

Introduction
This Special Instruction will modify the emergency stop circuit on the Electronic Instrument Panel. The existing circuit will allow the engine to restart after the emergency stop button is reset. The modification will change the circuit so that the Engine Control Switch must be reset after an emergency stop shutdown in order to restart the engine.This modification is recommended for the 3500B engines that are used in the following applications: marine propulsion, marine auxiliary with the Electronic Instrument Panel (EIP), land and offshore petroleum engines with the EIP and land EPG with the EIP. This modification is not for the EMCP II/II+ generator sets.This Special Instruction contains the procedures for modifying engines with premium wiring and for modifying engines with standard wiring. Verify which wiring package (standard or premium) that your engine has, and follow the corresponding procedures.Description and FunctionThis modification changes the emergency stop circuit. The change will require the Engine Control Switch (ECS) to be reset after an emergency stop shutdown in order to start the engine. The current emergency stop circuit will initiate cranking after the emergency stop button is reset without resetting the ECS. Once the modification is installed, pushing the emergency stop button will remove power from the Primary Engine Control Module (PECM) relay and the Secondary Engine Control Module (SECM) relay. The PECM relay then removes power from the Primary ECM. The SECM relay removes power from the Secondary ECM. The emergency stop lockout relay and the emergency stop relay energize in order to complete the circuit for the PECM relay and the SECM relay. These relays stay energized until the ECS is placed in the OFF/RESET position. Resetting the emergency stop switch will not allow the engine to start until the ECS has been placed in the OFF/RESET position, and then to START or AUTO.Glossary of TermsADEM Box - The ADEM box contains the PECM and the SECM. The premium wiring and instrumentation package contains the ADEM box.Engine Control Module (ECM) - The ECM is referred to as the ADEM II on 3500B engines.Engine Control Switch (ECS) - The ECS is located on the EIP or on the ADEM box. The ECS is the master control for the engine.Emergency Stop - An emergency stop is a method to shutdown the engine in an emergency. An emergency stop shutdown is not used for routine engine shutdowns.Electronic Instrument Panel (EIP) - The EIP is used with standard wiring on the following applications: marine, marine auxiliary, petroleum and land based package generator sets. Engine Monitoring System (EMS, EMS-II and EMS-III) - This module is used to indicate up to ten alarms and shutdowns. The module will also indicate a numeric value for various engine parameters on an LCD display.Independent Shutdown Relay (ISDR) - The ISDR is a means for the customer to supply 24 VDC to a separate relay specifically dedicated to shutting down the engine control modules. Completion of this Special Instruction, REHS0589, will make the ISDR a latching feature. Activating the ISDR will then require resetting the ECS prior to restarting the engine. Energizing the ISDR will not activate the air shutoffs.PECM - Primary Engine Control ModuleSECM - Secondary Engine Control Module. The SECM is used for applications in marine propulsion.Threaded Insert - The threaded insert is a fastener that compresses during installation. The fastener can be installed permanently from one side of a panel.Emergency Stop Lockout Relay - This relay will remove power from the PECM relay and the SECM relay until the ECS is returned to OFF/RESET and then moved to START.Emergency Stop Relay - This relay is controlled by the emergency stop lockout relay. The emergency stop relay switches power to the PECM and the SECM relay.Premium Wiring - The following components are designed to comply with marine requirements: harness, ECM, instrument panel and power distribution box.Standard Wiring - The electrical harness and the EIP that are used for standard applications.Installation
Table 1
Required Parts for Standard Wiring    
Part     Description     Quantity    
9Y-2921     Relay     2    
111-1323     Contact Block     1    
132-8095     Wiring Diagram     1    
132-8103     Wiring Diagram     1    
132-8269     Wiring Diagram     1    
174-1438     Harness     1    
7S-1197     Screws     2    
3B-4501     Lockwashers     2    
4B-4863     Washers     2    
176-1691     Threaded Inserts     2    
3S-2093     Cable Straps     10    
9X-8248     Heat Tube     1    
Table 2
Required Parts for Premium Wiring    
Part     Description     Quantity    
4B-4863     Washer     2    
6D-5801     Nut     2    
9Y-2921     Relay     2    
111-1323     Contact Block     1    
175-5041     Wiring Harness     1    
175-5043     Plate     1    
3S-2093     Cable Straps     10    
9X-8248     Heat Tube     1    
Table 3
Special Tools    
Part Number    Part    
178-7635     Installation Tool (Threaded Insert) (8-32)    
146-4080     Digital Multimeter    Rework Procedure
Standard Wiring Installation
Remove all electrical power from the engine and from the control panel. Verify that the 24 VDC power supply is disconnected.
Open the front panel of the EIP. Locate the EIP internal harness.
Locate the conductor that connects the emergency stop contact 1 to the Primary Engine Control Module Relay (PECMR) pin 86. Disconnect both ends of this conductor. If the engine has two engine control modules, disconnect the wire that is connected to pin 86