Mercury MERCRUISER Service Manual

Important Information, Maintenance, and
Troubleshooting
Section 1D - Troubleshooting
Table of Contents
Introduction........................................................................ 1D-2
Before You Begin Troubleshooting.............................1D-2
Situational Awareness................................................ 1D-2
General Troubleshooting Guidelines.......................... 1D-2
Visual/Physical Check....................................................... 1D-3
Emission Control Fault Indicators...................................... 1D-4
Diagnostic Roadmap......................................................... 1D-4
Chart R1: Engine System Fails to Power Up..............1D-5
Chart R2: OBD‑M Lamp Does Not Self‑Test..............1D-6
Chart R3: Crankshaft Fails to Rotate..........................1D-7
Chart R4: Engine Cranks Over but Will Not Start.......1D-8
Chart R5: Hard Start...................................................1D-9
Chart R6: Engine Stalls............................................ 1D-10
Diagnosis by Symptom.................................................... 1D-11
Chart S1: Engine Surges..........................................1D-11
Chart S2: Lack of Power, Sluggish, or Spongy........ 1D-11
Chart S3: Detonation or Spark Knock...................... 1D-12
Chart S4: Hesitation, Sag, or Stumble......................1D-14
Chart S5: Engine Misses.......................................... 1D-15
Chart S6: Rough, Unstable, or Incorrect Idle and
Stalling.................................................................. 1D-16
Chart S7: Poor Fuel Economy..................................1D-16
Chart S8: Dieseling or Run‑On.................................1D-17
Chart S9: Backfire.................................................... 1D-18
Troubleshooting Tests..................................................... 1D-19
Chart T1: Main Power Relay Test............................ 1D-19
Chart T2: Fuel System Electrical Test...................... 1D-20
Chart T3: Fuel System Diagnosis.............................1D-20
Chart T4: Ignition System Test................................. 1D-21
Troubleshooting Shift Problems.......................................1D-22
PCM 112 Calibration Information.....................................1D-22
Default Sensor Values..............................................1D-22
Fault Conditions........................................................1D-22
Sticky and Nonsticky Faults......................................1D-22
OBD‑M Faults...........................................................1D-22
CDS G3 Service Tool...................................................... 1D-22
Introduction...............................................................1D-22
Connecting and Starting G3..................................... 1D-22
CDS G3 Service Tool Home Screen Overview........ 1D-24
CDS G3 Fault List.....................................................1D-25
Troubleshooting
90-8M0099748 eng DECEMBER 2015 © 2016 Mercury Marine Page 1D-1
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Mercury MERCRUISER Specifications

General

Brand	Mercury
Model	MERCRUISER
Category	Engine
Language	English