Mercruiser 5.0 MPI DDT scantool codes.

Hi all, We have an 03 MPI 5.0 mercruiser at the workshop, When the DDT scan tool Is connected It comes up as code 7, Which shows to be " Limiter". Now the book that comes with the DDT over here In Aus shows nothing on the " Limiter" as such,

Can someone shed some light on excatly whats going on, and what should be replaced or checked.

The engine also beeps every so often.

Im guessing Its something to do with the rev limiter? ECU maybe?

Cheers.

So today after more testing and checking, Ive come to this,

Engine shows 90% power. Yes the IAC has been done, and I checked the new one.. Im guessing 90% power is because guardian Is working? I cant help but wonder If maybe the engine is running a little warm, hence why the guardian is dropping the power.... Although the temp guage looks fine.... Its a twin engine configurment, And Ive swapped all corresponding electrial items over, Same problem persists.....


Anyone have any Idear????????

If you think it is running warm use a laser temperature gun on both engines and compare the results. Check the thermostat housings, exhaust and intake manifolds in several spots. It may be a water flow issue from a worn impeller or blockage from debris.

Never seen "7" show as a valid DTC and any GM-based marine engine; can't say if it would be valid for a non-US product.

Sure you have the correct cartridge in the DDT and it is seated?

Only mention i can find in the manuals (2000 and up) of limiter is in the REV LIMITER context. Another set of LIMIT parameters show up in the system info available charts.

A 2 beeps/minute audio signal is a good sign the Guardian Strategy has been invoked. Ignoring the "7", it shouldn't bee to hard to scan the parameters available and find the one(s) driving the Guardian mode. Then you can determine if it a hard fault and repair as appropriate. If the 90% power status is real, there's a whole list of sensors/circuits that are valid causes.

looked in my manual,#36 Service Manual
#36 ECM 555 Diagnostics S/N OM300000 and Above
Serial Number
0M300000 and Above
com
Rechain)
Belgium
ECM 555 Diagnostics

can't find anything for a no. 7, there all codes. are you using the correct software version.also I would have 2 check but I thought when the guardian system took over it put you into limp mode, enough RPM"S to get you to shore? not 90%, and its a steady beeping. intermittent is somthing dumb like check the fluid level in your drive monitor.

oops, just checked, hope this helps.

Warning Chart
The engine warning system incorporates an audio alarm and, if installed, Smartcraft
Gauges System. When the key switch is turned to the ON position, the audio alarm will
momentarily activate to test thewarning system. The alarm should sound once if the system
is operable. This table is a guick guide, showingwhat warning output will accompany a fault.
Fault Smartcraft
Gauges
Audio
Alarm
Available
Power
Description
ECT CKT HI Yes 2 Bp/min 90% Open
ECT CKT LO Yes 2 Bp/min 90% Short
ECT Coolant
Overheat
Yes Constant 6 - 100 % Engine guardian
overheat condition
EST 1 Open 1 Yes 2 Bp/min 100% Coil harness wire open
EST 1 Short 1 Yes 2 Bp/min 100% Coil harness wire short
Fuel Injector 1-7-4-6
Open
Yes 2 Bp/min 100% Fuel injector wire open
Fuel Injector 3-5-2-8
Open
Yes 2 Bp/min 100% Fuel injector wire open
Guardian Strategy Yes Constant 0% - 100% Protection Strategy
IAC Output LO/HI 2 Yes 2 Bp/min 90% Open
Knock Sensor 1 Lo Yes 2 Bp/min 90% Open
Knock Sensor 1 Hi Yes 2 Bp/min 90% Short
Low Drive Lube
Strategy
Yes Constant 100% Low oil in sterndrive
Low Oil Pressure
Strategy
Yes Constant 0 - 100% Low oil pressure strategy
NOTE: If any 5v sensor becomes shorted to ground the engine will not start. If the engine
is operating when the short occurs the engine may stop operating and will not start.
NOTE: 1 GM EFI ignition system failure open or shorted, driver will flag EST 1 fault.
NOTE: 2 TPS must see 5% throttle then back to 0% to flag IAC fault.
NOTE: 3 2-wire sensor open will read sensor Hi on scan tool.
NOTE: 4VDC PWR Low - if shorted or no voltage engine will not start; if VDC PWR voltage
falls velow 22 volts will set sensor faults.
NOTE: 5 Shift Switch - will activate code when engine rpm are above 3500 rpm and 40%
load.
GENERAL INFORMATION SERVICE MANUAL NUMBER 36
Page

Warning Chart (continued)
Fault Smartcraft
Gauges
Audio
Alarm
Available
Power
Description
Main Power Relay
Output
Yes No N/A Engine will not start
Main Power Relay
Backfeed
Yes No N/A Engine will not start
MAP Sensor 1 Input
High
Yes 2 Bp/min 90% High voltage or short
MAP Sensor 1 Input
Low
Yes 2 Bp/min 90% Open, no visual on
SC1000
Oil PSI CKT Hi Yes 2 Bp/min 90% Open, defaults to 50.7 psi
Oil PSI CKT Lo Yes 2 Bp/min 90% Short, defaults to 50.7 psi
Overspeed Yes Constant rpm limit Engine over rpm limit
Pitot CKT Hi No No 100% Short or high voltage
Pitot CKT Lo No No 100% Open
Sea Pump PSI Lo Yes Constant 6-100%
Guardian Strategy
Sea Pump CKT Hi Yes 2 Bp/min 90% Open - 0 psi reading
Sea Pump CKT Lo Yes 2 Bp/min 90% Voltage high or short
Sea Water Temp No No N/A Defaults to --31 degreesC
Fuel Level #1 No No N/A Only if turned on
STB EMCT CKT Hi N/A N/A N/A N/A
STB EMCT CKT Lo N/A N/A N/A N/A
STB EMCT CKT
Overheat
N/A N/A N/A N/A
NOTE: If any 5v sensor becomes shorted to ground the engine will not start. If the engine
is operating when the short occurs the engine may stop operating and will not start.
NOTE: 1 GM EFI ignition system failure open or shorted, driver will flag EST 1 fault.
NOTE: 2 TPS must see 5% throttle then back to 0% to flag IAC fault.
NOTE: 3 2-wire sensor open will read sensor Hi on scan tool.
NOTE: 4VDC PWR Low - if shorted or no voltage engine will not start; if VDC PWR voltage
falls velow 22 volts will set sensor faults.
NOTE: 5 Shift Switch - will activate code when engine rpm are above 3500 rpm and 40%

Thanks heaps for your Info, I've checked the cartridge for the DDT and re checked the seating all seems fine, After more tests today Im still stuck with the LED lighting up on number 7, (Limiter)..... Ive been all through the wiring, swapped just about everything from motor to motor and still this problem persists........

I'll have another play with the DDT tomorrow and swap some stuff over agian........


Ahhhh What a headache this job has turned Into!.......( Its been to 2 other mercruiser techs in the area and none have fixed it.... Now im stuck with the bugger!)

Cheers

see if you can clear the code and see if it comes back. what kind of out drives and prop are you running,maybe get lucky and just spun a hub?

iceknight66 said:

Hi all, We have an 03 MPI 5.0 mercruiser at the workshop, When the DDT scan tool Is connected It comes up as code 7, Which shows to be " Limiter". Now the book that comes with the DDT over here In Aus shows nothing on the " Limiter" as such,

Can someone shed some light on excatly whats going on, and what should be replaced or checked.

The engine also beeps every so often.

Im guessing Its something to do with the rev limiter? ECU maybe?

Cheers.

Click to expand...

did you ever figure this out I have the exact same problem exact same power engine does not need to be running just turn on the jet and wait