Section 7 - Troubleshooting
Page 78
90-8M0099741
eng
JUNE 2015
Diagnosing EFI Problems
Your authorized Mercury MerCruiser dealer has the proper service tools for diagnosing problems on electronic fuel injection
(EFI) systems. The engine control module (ECM) on these engines has the ability to detect some problems with the system
when they occur, and store a Trouble Code in the ECMs memory. This code can then be read later by a service technician
using a special diagnostic tool.
Diagnosing DTS Problems
Your authorized Mercury MerCruiser dealer has the proper service tools for diagnosing problems on digital throttle and shift
(DTS) systems. The engine control module (ECM)/propulsion control module (PCM) on these engines has the ability to detect
some problems with the system when they occur, and store a Trouble Code in the ECM/PCMs memory. This code can then be
read later by a service technician using a special diagnostic tool.
Engine Guardian System
The Engine Guardian System monitors the critical sensors on the engine for any early indications of problems. The system will
respond to a problem by emitting a continuous beep and/or reducing engine power in order to provide engine protection.
If Guardian System has been activated, reduce throttle speed. The horn will turn off when throttle speed is within the allowable
limit. Consult an authorized Mercury MerCruiser dealer for assistance.
Troubleshooting Charts
Starter Motor Will Not Crank Engine, or Cranks Slowly
Possible Cause
Remedy
Battery switch turned off.
Turn the switch on.
Remote control not in neutral position.
Position the control lever in neutral.
Open circuit breaker or fuse.
Check and reset the main power circuit breaker or replace the fuse. Check the
5‑amp fuse on the power harness connected to the battery, and replace if
necessary.
Loose or dirty electrical connections or
damaged wiring.
Check all electrical connections and wires (especially battery cables). Clean
and tighten all faulty connections.
Bad battery or low battery voltage.
Test the battery and charge if necessary; replace if bad.
Lanyard stop switch activated.
Check the lanyard stop switch.
Engine Will Not Start or Is Hard to Start
Possible Cause
Remedy
Lanyard stop switch activated.
Check the lanyard stop switch.
Improper starting procedure.
Read the starting procedure.
Insufficient fuel supply.
Fill fuel tank or open valve.
Faulty ignition system component.
Service the ignition system.
Clogged fuel filter.
Replace fuel filter.
Stale or contaminated fuel.
Drain fuel tank. Fill with fresh fuel.
Fuel line or tank vent line kinked or clogged. Replace kinked lines or blow out lines with compressed air to remove
obstruction.
Faulty wire connections.
Check wire connections.
EFI system fault.
Have EFI system checked by an authorized Mercury MerCruiser dealer.
