Home
Mercury
Outboard Motor
V8 250
Mercury V8 250 User Manual
5
of 1
of 1 rating
302 pages
Give review
Manual
Specs
To Next Page
To Next Page
To Previous Page
To Previous Page
Loading...
Wire Color Code Abbreviations
Wire Color Abbreviations
BLK
Black
BLU
Blue
BRN
Brown
GRY or GRA
Gray
GRN
Green
ORN or ORG
Orange
PNK
Pink
PPL or PUR
Purple
RED
Red
TAN
Tan
WHT
White
YEL
Yellow
LT or LIT
Light
DK or DRK
Dark
Troubleshooting and Diagnostics
90-8M0146617
eng
JULY 2018
© 2018 Mercury Marine
Page 7B-5
272
274
Table of Contents
Important Information 1
11
Table of Contents
11
Overview
12
Speed/Density Theory
12
Stoichiometry, Equivalency Ratio, and Emissions Control
12
Oxygen (O2) Sensor
13
Open-Loop and Closed-Loop Operation
13
Advanced Range Optimization
14
Propulsion Control Module (PCM)
14
Description
14
Engine Guardian System
15
Important Terms
15
Important Information 1
21
Glossary
22
Abbreviations
24
General Reference Charts
25
Manifold Vacuum and Pressure
25
Altitude and Barometric Pressure
26
Vacuum Gauge Versus MAP Sensor
27
Centigrade to Fahrenheit Conversion
28
Section 2A - Pcm 112 Important Information and Pinouts a
29
Important Information
30
Propulsion Control Module (PCM) Overview
30
Important PCM Notes
31
Test Equipment
31
Load Balancing
32
Software and Adaptive Speed Control
32
Connector
33
PCM 112 Pinouts
33
General Troubleshooting and Cds G3 3
55
About CDS G3
56
Connecting and Starting CDS G3
56
Connection to the Engine
56
Installing CDS G3
56
Troubleshooting with the Computer Diagnostic System (CDS G3)
56
Connection to the Junction Box or Diagnostic Port
57
If CDS G3 Does Not Communicate with the System
57
Starting CDS G3
57
CDS G3 Operation and Screen Descriptions
58
Home Screen
58
Print Screen/Print Report
59
Selecting an Ebom
59
Reflash Screen
60
Configuration Screen
61
Diagnostics Screen
61
Module Data Screen
62
CDS G3 and Diagnostic Fault Resolution
67
How to Begin
67
Addressing Faults
68
Fault Codes
68
Diagnosing Intermittent Problems
69
Visual/Physical Check
69
Fault Codes
91
Mercury UFC List
93
Aev_Outputfault
98
Authtimeout
98
CDS G3 Freeze Frame Faults
98
Barorange
99
Camshaft_Encoder_Fault
99
Crosscheck_Failed
99
Demandsensor1_Rangehigh
100
Demandsensor1_Rangelow
100
Demandsensor2_Rangehigh
100
Demandsensor2_Rangelow
101
Demandsensor_Diff
101
Demand_Xcheck_Diff
101
Dmdsense1_Noadapt
102
Dmdsense2_Noadapt
102
Dual_Can_Soh_Faults
102
Dual_Demandsen_Fault
103
Dual_Shiftdemandsen_Fault
103
Dual_Shiftpossen_Fault
103
Dual_Tps_Faults
104
Egt_Overtemp
104
Egt_Rangehigh
104
Egt_Rangelow
105
Esclossofcontrol
105
Esc_Desiredactualdiff
105
Esc_Noadapt_Forward
106
Esc_Noadapt_Reverse
106
Esc_Timeout
106
Est1_Outputfault
107
Est2_Outputfault
107
Est3_Outputfault
107
Est4_Outputfault
107
Estop_Active
107
Etc_Loss_Of_Control
108
Etc_Outputfault
108
Etc_Sticking
108
Encoderfaultcrankcamtrigger
109
Etc_Tpsdisagree
109
Fulp_Outputfault
109
Guardian_Active
110
Guardian_Egttemp
110
Guardian_Oilpressure
110
Guardian_Oil_Temp_Derate
111
Guardian_Overheat
111
Guardian_Overspeed
112
Guardian_Uxpowerlimit
112
Horn_Outputfault
113
Iat_Rangehigh
113
Iat_Rangelow
113
Map_Angle_Rangehigh
115
Map_Angle_Rangelow
115
Map_Time_Rangehigh
115
Mapr_Tps1Rationality
116
Map_Time_Rangelow
116
Mapr_Tps2Rationality
117
Microchi_Pwm_Adc
117
Neutral_Overspeed
117
O2Control_Itermhighport
118
O2Control_Itermlowport
118
Oillevelinvalid
118
Oillevel_Critically_Low
119
Oillevel_Rangehigh
119
Oillevel_Sensor_Faulted
119
Oillevel_Sensor_Invalid
120
Oilpress_Low
120
Oilpress_Rangehigh
120
Oilpress_Rangelow
121
Oiltemp_Rangehigh
121
Oiltemp_Rangelow
121
Rxdoc1_Soh
121
Rxdoc2_Soh
122
Rxdoc3_Soh
122
Rxdoc10_Soh
123
Rxdoc7_Soh
123
Rxdoc9_Soh
123
Rxdoc11_Soh
124
Security_Device_Missing
124
Security_Locked
124
Security_Setup
125
Shft_Outputfault
125
Shiftdemandsensor_Diff
125
Shiftdmdsensor1_Rangehigh
126
Shiftdmdsensor1_Rangelow
126
Shiftdmdsensor2_Rangehigh
126
Shiftdmdsensor2_Rangelow
126
Shiftpos2_Rangehigh
127
Shiftpos_Rangehigh
127
Shiftpos_Rangelow
127
Shiftpos2_Rangelow
128
Shiftpositionsensor_Diff
128
Shift_Xcheck_Diff
128
Spi_Crosscheckdata_Soh
129
Stbdect_Overtemp
129
Stbdect_Rangehigh
129
Stbdect_Rangelow
130
Strt_Outputfault
130
Sysvolt_Faultblocker
130
Sysvolt_Rangehigh
131
Sysvolt_Rangelow
131
Tps1_Etc_Noadapt
131
Tps1_Rangehigh
132
Tps1_Rangelow
132
Tps2_Etc_Noadapt
132
Tps2_Rangehigh
132
Tps2_Rangelow
133
Trmd_Outputfault
133
Trmu_Outputfault
133
Trimpos_Rangehigh
134
Trimpos_Rangelow
134
Uego1_Htrlwrlimit
134
Uego1_Sensor_Open
135
Uego1_Sensor_Short
136
Watchdog_Active
136
Waterinfuel_Rangelow
136
Xdrpa_Rangehigh
137
Xdrpa_Rangelow
137
Xdrpb_Rangehigh
137
Xdrpb_Rangelow
137
Xdrpc_Rangehigh
138
Xdrpc_Rangelow
138
Sensors, Actuators, Relays, and Accessories
139
General Sensor Troubleshooting
140
Sensor Tests
140
Swapping Sensors
140
Sensor Opens and Shorts
141
Sensor Signal Circuit Test
141
Three-Wire Sensor Opens and Shorts
141
Three-Wire Sensor Power Supply and Ground Circuit Test
141
Two-Wire Sensor Opens and Shorts
141
Wire Color Code Abbreviations
142
Sensor Power a - DTS
144
Circuit Description
145
Sensor Power a - Mechanical
146
Circuit Description
147
Sensor Power
147
Block Water Pressure Sensor
148
Circuit Description
148
Sensor Power
148
Block Water Pressure Sensor Tests
149
Block Water Pressure Sensor Installation
150
Block Water Pressure Sensor Removal
150
Camshaft Position Sensor
150
Camshaft Position Sensor Tests
151
Camshaft Position Sensor Installation
152
Camshaft Position Sensor Removal
152
CPS Test
153
Crankshaft Position Sensor (CPS)
153
Crankshaft Position Sensor Installation
154
Crankshaft Position Sensor Removal
154
ECT Sensor Test
155
Engine Coolant Temperature (ECT) Sensor
155
ECT Sensor Removal
156
ECT Sensor Installation
157
EGT Sensor Test
157
Exhaust Gas Temperature (EGT) Sensor
157
EGT Sensor Removal
159
EGT Sensor Installation
160
Intake Air Temperature (IAT) Sensor
160
IAT Sensor Test
161
IAT Sensor Removal
162
IAT Sensor Installation
163
Manifold Absolute Pressure (MAP) Sensor
164
MAP Sensor Test
164
MAP Sensor Installation
165
MAP Sensor Removal
165
Oil Level Sensor
165
Oil Level Sensor Test
166
Oil Level Sensor Installation
167
Oil Level Sensor Removal
167
Oil Pressure Sensor
168
Oil Pressure Sensor Test
168
Oil Pressure Sensor Removal
169
Oil Pressure Sensor Installation
170
Oil Temperature Sensor
170
Oil Temperature Sensor Test
170
Oil Temperature Sensor Installation
171
Oil Temperature Sensor Removal
171
O2 Sensor Test
172
Oxygen (O2) Sensor
172
O2 Sensor Removal
173
O2 Sensor Installation
174
Pitot Pressure Sensor
174
Pitot Pressure Sensor Test
174
Pitot Pressure Sensor Removal
175
Pitot Pressure Sensor Installation
176
Shift Demand Sensor
176
Shift Demand Sensor Testing
176
Shift Demand Sensor Removal
177
Shift Demand Sensor Installation
178
Throttle Demand Sensor
178
Throttle Demand Sensor Testing
179
Throttle Demand Sensor Removal
180
Throttle Demand Sensor Installation
181
Trim Position Sensor
181
Water-In-Fuel (WIF) Sensor
181
WIF Sensor Test
182
WIF Sensor Removal and Installation
183
Sensors, Actuators, Relays, and Accessories
185
Electronic Throttle Control (ETC)
186
Overview
186
Troubleshooting the ETC
186
Fuel Pump Relay
188
Main Power Relay (MPR)
189
Start Relay
190
Shift Actuator
192
Shift Actuator Harness Connector Pin out
192
Shift Actuator Troubleshooting
193
Shift Control
193
Sensors, Actuators, Relays, and Accessories
197
Advanced Sound Control
198
Troubleshooting
198
Moving Propeller (MP) Alert
200
Power Steering
200
Troubleshooting an Inoperable Power Steering Pump
201
Analog Gauges (DTS Only)
203
Boat Harness
204
Battery Isolator Troubleshooting
205
Diagnostics (RS48)
205
Electrical Systems
207
Ignition Specifications - V6 Models
208
Ignition Specifications - V8 Models
208
Ignition Coil Test - CDS G3
209
Ignition Coil Tests - Digital Multimeter
209
Ignition Coils
209
Ignition Coil Wiring Diagram - V6
210
Wire Color Code Abbreviations
211
Ignition Coil Wiring Diagram - V8
212
Ignition Coil Resistance Test
213
Spark Plug Wires
213
Spark Plug Wire Resistance - V6 Models
214
Spark Plug Wire Resistance - V8 Models
214
Electrical Systems
215
Battery
216
Battery Cable Test
216
Battery Specifications
216
Charging and Starting Specifications
216
Battery Precautions
217
Charging a Discharged Battery
217
Replacement Parts
217
Fuses
218
Alternator Description
219
Charging System
219
Charging System Components
219
Alternator
220
Charging System Inspection
220
Charging System Circuitry Tests
221
Starting System
224
Starting System Components and Connections - DTS
224
Starting System Components and Connections - Mechanical
225
Starting System Electrical Checks
226
Key Switch Test (Four Position)
227
Key Switch Test (Three Position)
228
Electrical Systems
229
Condition/Problem
230
Electrical System Troubleshooting
230
General Checks
230
Power Trim Electrical Circuit
230
Problem/Solution
230
Troubleshooting the down Circuit
235
Troubleshooting the up Circuit
236
Trim Circuit
237
Troubleshooting the down and up Circuits (All Circuits Inoperative)
237
Trim up Circuit
238
Power Trim Relay Test
239
Trim down Circuit
239
Trim Position Sensor
240
Trim Position Sensor Troubleshooting
240
Troubleshooting the Trim Position Circuit
240
Testing the Trim Position Sensor Circuit with DMT 2004A
242
Trim Position Sensor Location
242
Trim Switches and Sensor - DTS
243
Trim Switches and Sensor - Mechanical
244
Electrical Systems
245
Condition/Problem
246
Electrical System Troubleshooting
246
General Checks
246
Power Trim Electrical Circuit
246
Problem/Solution
246
Troubleshooting the down Circuit
249
Troubleshooting the up Circuit
250
Trim Circuit
251
Troubleshooting the down and up Circuits (All Circuits Inoperative)
251
Trim up Circuit
252
Power Trim Relay Test
253
Trim down Circuit
253
Trim Position Sensor
254
Trim Position Sensor Troubleshooting
254
Troubleshooting the Trim Position Circuit
254
Testing the Trim Position Sensor with DMT 2004A
256
Trim Position Sensor Location
256
Fuel System
259
Fuel Injector
260
Fuel System
260
Fuel System Overview
260
Fuel System Specifications
260
Theory of Operation
260
In-Line Fuel Filter
261
V6 Fuel Flow Diagram
262
V8 Fuel Flow Diagram
264
Fuel Supply Module (FSM)
265
Fuel Supply Module (FSM) Description
265
Fuel Lift Pump
266
Fuel Pressure Regulator
266
High-Pressure Fuel Pump
267
Fuel System
269
Antisiphon Valves
270
Fuel Component Troubleshooting and Diagnostics
270
Fuel Lift Pump
270
Fuel Supply Module (FSM)
270
High-Pressure Fuel Pump
271
Fuel Injector Resistance Test
272
Fuel Pressure Calculations, Engine Running
272
Wire Color Code Abbreviations
273
14-Pin Data Harness - DTS
280
Wire Color Code Abbreviations
281
14-Pin Data Harness - Mechanical
282
CAN Circuits - DTS
284
CAN Circuits - Mechanical
286
Clean Power
286
4.6L V8 DTS Wiring Diagram
292
4.6L V8 Non-DTS Wiring Diagram
295
3.4L V6 DTS Wiring Diagram
296
3.4L V6 Non-DTS Wiring Diagram
299
5
Based on 1 rating
Ask a question
Give review
Questions and Answers:
Need help?
Do you have a question about the Mercury V8 250 and is the answer not in the manual?
Ask a question
Mercury V8 250 Specifications
General
Brand
Mercury
Model
V8 250
Category
Outboard Motor
Language
English
Related product manuals
Mercury V8 300
302 pages
Mercury 250 VERADO
145 pages
Mercury 250 Verado FourStroke
144 pages
Mercury OptiMax 250
39 pages
Mercury 250 Pro XS OptiMax
155 pages
Mercury V6 175
302 pages
Mercury V6 200
302 pages
Mercury 200 VERADO
145 pages
Mercury 175 Verado
144 pages
Mercury 150 Verado FourStroke
144 pages
Mercury 200 Verado FourStroke
144 pages
Mercury 175 Verado FourStroke
144 pages
To Next PageTo Next PageTo Previous PageTo Previous Page
Loading...
Need help?
General
