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seadoosnipe
09-03-08, 12:00 PM
Here, I want to start a thread on the 4-TEC's and will be adding information as I go along. Last year, there were no members here with issues or questions about the 4-TEC. This only goes to show you how well the design of this engine truly is. It can be an electrical nightmare if you have a short, because it's entirely computerized, but when it's running great, you can't beat it for performance.

Mechanics like me are limited on what we can do for these, since they require the B.U.D.S. to trouble shoot.

I'm going to start this thread with the acronyms that are commonly used in threads and posts and in time, will add posts such as winterizing and maintenance, since the info we have generically in the forum, applies to the 2 stroke engines.

If there is a specific topic you'd like to see covered, feel free to PM me. I will leave this thread locked, since I want to make sure that the info given, is factual from sources like our manuals and other research and not "hear say".

These Acronyms apply to all Seadoo's

ADC......................Analog to Digital Conversion
AC........................Alternate Current
AP........................Air Pressure Sensor
ATS......................Air Temperature Sensor
B.U.D.S..................Bombardier Utility and Diagnostic Software
CDI.......................Capacitor Discharge Ignition
CPS......................Crankshaft Position Indicator
CSI.......................Cooling System Indicator
DC........................Direct Current
DESS.....................Digital Electronic Security System
DI.........................Direct Injected
E.I.N.....................Engine Identification Number
ECM......................Electronic Control Module
ECU......................Electric Control Unit
EMS......................Engine Management System
EPA......................Environmental Protectioin Agency (USA)
HP........................Horse Power
LED.......................Light Emitting Diode
MAG.....................Magneto
MPEM...................Multi-Purpose Electronic Module
MPH.....................Mile Per Hour ( I hope I don't have to explain this one!)
MPI......................Multi Protocol Interface
N.A......................Not Applicable
OPT.....................Optional
P/N......................Part Number
PFD......................Personal Flotation Device
PSI......................Pounds Per Square Inch
PTO.....................Power Take Off
RAVE....................Rotax Adjustable Variable Exhaust
RFI......................Rotax Fuel Injection
RPM.....................Revolutions Per Minute
STD.....................Standard
TBD.....................To Be Determined
TDC.....................Top Dead Center
TPS.....................Throttle Position Sensor
VDC.....................Volts Direct Current
VCK.....................Vehicle Communication Kit
VTS.....................Variable Trim System
WTS....................Water Temperature sensor

There will be more specifics to follow. Thanks for reading the thread!...:cheers:

seadoosnipe
09-03-08, 01:03 PM
A brief look at the electrical system of the 4-TEC

Because the MPEM has been the primary controller (brain) for most of the Seadoo’s through the years, I think there is a mis-conception on their place in the 4-TEC EMS (engine management system).
With the 4-TEC engines, the electrical system is managed by micro-controllers that work together, to control your engine. The MPEM is the primary manager of all the electronics. The MPEM receives, interprets and distributes the information it receives from the ECM, which after intrepreting that info, sends it back to the ECM for adjustments to be made. At this point, the ECM is considered to be the primary controller to the ECM. Do not confuse the two systems. The ECM must have the MPEM to operate. But it’s just a “logic and power distribution controller”. The ECM is primary to the EMS, in order to run the 4-TEC engine efficiently.

This is the basic set-up in which these components work together. When you connect your lanyard to your DESS post, if it’s the correct lanyard, you get two beeps. The MPEM is powered up. It sends power to the ECM, Information center, Speed sensor, Fuel level sending unit, the “beeper” and the depth gage. The other features that start the craft are now active. The start/stop switch, starting solenoid, fuel pump, fuel injectors, ignition coils and the tip over protection system (TPS).

When these systems are all green and good to go (you’ll know, you get the two beeps) the ECM begins controlling the several sensors to run your engine. In order to get a start, the ECM receives and controls the information from several sensors. Those inputs are listed here.

TPS……………………..Throttle position
MAPS………………….Manifold air pressure
MATS………………….Manifold air temperature
CTS……………………..Coolant Temperature
EGTS……………………Exhaust Gas Temperature
KS………………………..Knock Sensor
OPS……………………..Oil Pressure Sensor
CPS………………………Crankshaft position sensor
DESS…………………….Digital electronic security system
TOPS…………………….Tip-Over protection system
Start/stop switch

Idle Bypass Valve

Now, when receiving these signals, the Engine Control Module provides the following outputs.
Fuel pump…………….
Starter solenoid……
Ignition coil (there are 3 of them)
Fuel injectors
Idle bypass valve
And, the communication port for your sevice mechanic to connect to B.U.D.S. through the VCK to troubleshoot and make adjustments to your operating systems.

While there are some things we can do to troubleshoot the 4-TEC’s (some fault codes are visible from your information center), for the most part, we are very limited. This engine is a very high tec and computerized engine and the owner or any “un-qualified” mechanic should not attempt to bypass any of the electrical control features without the understanding that you may cause terminal damage to the MPEM and ECM. These repairs will be over $1200 bucks.
So, if you have a problem with your 4-TEC, don’t just let anyone work on it. You can find limited information and help here, but for the most part, because of the sophiscated system of the EMS, it will have to go to an OEM certified mechanic.

seadoosnipe
09-12-08, 11:34 PM
I know I’ve got a couple things in this post that will be redundant to another, but I want to cover all the bases on these things in the next few weeks, so I’m going chapter by chapter and sometimes, a term or procedure may be used again.

First, the Jargon or acronyms:
1. SC or SCIC: These two are used in conjunction with each other. SC is supercharged and SCIC is supercharged with an intercooler.
2.Ceramic washers: The ceramic washers were first designed because of their characteristics of dissipating heat from slippage between the charger and the gear that drives it. Ceramic is a great thermal insulator for keeping friction and heat at a minimum. Unfortunately, it was found that use of the synthetic oils were causing them to deterior to the point that catastrophic failure occurred in many skis before Seadoo decided it was time to put out a supplemental on changing to the stainless washers. The downfall, stainless isn’t a good thermal reducing compound.
3.Closed loop cooling: The 4-TEC engines are a closed loop engine. Which means, unlike its 2 stroke counter parts, its cooling system is separated from the sea/river or lake water you’re riding in. With a cooling medium of 50% ethylene glycol and 50% water, you don’t have to worry about micro organisms living in the engines water jacket. No buildup of aluminum oxide or galvanic corrosion in the cooling circuit. You do have a water pump and a radiator (heat exchanger in the ride plate) that must be maintained and after a few years of running it. I recommend a full flush and change out in the winter time. You can also by a hydrometer and literally check the strength of the coolant each season. You may find, under your specific riding conditions that it only needs to be changed every couple years.
4.MPEM: The multi purpose electronic module in the 4-tec’s work with the ECM (electronic module) and the “Engine Management System”. The purpose of the mpem is to receive, interpret and distribute information. In 1996, Rotax first went to the MPEM for use with the new Digital Electronic Security System (DESS). For several years, this was the primary control center (or brain) for the electrical system.
Now, with the 4 TEC’s “Engine Management System (EMS)” it has 2 roles. It still receives, interprets and distributes information, but it works with the engine control module (ECM) which picks up signals from anywhere between 10 to 14 sensors on your engine, sends that information into the MPEM, which interprets that information, then sends the processed information back to the ECM, telling it what the sensors signals mean or what it wants them to do. Then, the ECM makes those changes or adjustments. For example, if the ECM receives a signal from one of the sensors that is abnormal, it sends that signal to the MPEM for interpretation, the MPEM decides that this problem could be catastrophic to the engine, so it sends a signal back to the ECM and says to either run the engine at a reduced RPM or slow to limp mode; turn on the “engine service” light.
The ECM controls ignition modules and the fuel injectors. The MPEM receives the generated power from the magneto via the regulator/rectifier and provides the engine and ECM with its power supply.
5.Acronyms for sensors.
KS: knock sensor
CPS: Crankshaft Position Sensor
OPS: Oil Pressure Sensor
CTS: Coolant Temperature Sensor
CAPS: Camshaft Position Sensor
EGTS: Exhaust Gas Temperature Sensor
MAPS: Manifold Air Pressure Sensor
MATS: Manifold Air Temperature Sensor
TOPS: Tip-Over Protection System
6.B.U.D.S. (Bombardier Utility and Diagnostic Software) This is the computer software designed to communicate with your engine via the VCK (vehicle communication kit). There are several parts to this utility. It programs keys, does the electrical component inspection, diagnosing problems and making adjustments. Some of the first 4 TEC’s would throw a “P” code when there was a problem. You could look up the “P” code yourself, find out what sensor it was created by and just test or replace it. Sometimes it was just the wires or connecters, others it was the sensor. Well, the newer models have taken that away. If you get a “service” light of some type, you got to take it to a certified shop so it can be connect to that expensive computer to tell you that a $5 dollar part failed. Part, $5 dollars. Cost to replace it and re-set the computer, $250 (hypothetical)
7.Engine Fogging. You’ve heard this a million times I’m sure, “what is fogging”. Fogging is typically done at the end of the season. It’s sprayed into the engine, while running, to create a moisture barrier between the metal parts and the atmosphere. It provides lubrication and protection to the intake and exhaust valves and the crankshaft and cylinders.
8.Nautical terms:
Bilge: The bottom of the boat/ski.
Port: The left side of the boat/ski.
Starboard: The right side of the boat.
Fore and Aft: The forward and after ends of the boat/ski.
Gunwale: The sides of the boat.
Freeboard: The free distance of boat between the water’s surface and the top edge of the gunwale.
Transom: Back of ski/boat, where strength is added for the force created by the pump for pushing against.
Deck: The area of the boat you walk on.
Keel: The backbone of the boat/ski. This is the strongest part that will absorb the impact of “beaching” or maybe hitting a log in the water. While doing this, it may damage the keel a bit but normally not bad enough to breach the hulls integrity.
9.Water flooded engine: An engine that has either sunk or ingested water through towing. You have only a few hours to remove the water and start procedures to boil out the engine before permanent damage may occur.
10.Solenoid. The electrical connector/controller that provides power to the starter when the key engages the magnetic plunger of the switch. When they come together, contact is made and the current from the battery is sent to the starter.

seadoosnipe
09-12-08, 11:38 PM
IF you have specific information on the 4 TEC that you want to know about it's equipment, abbreviations etc....... Or if you just want to share info in this thread that I haven't even yet began to scratch the surface, please, write your material in a PM to me and I"ll look over it and in some cases, verify that the info is indeed correct, then I'll post it, citing the member that wrote the post.............this can be a fun thread if we all get involved.