Service Training
MALAGA
MACHINE ELECTRONICS
ELECTRONIC
CONTROL
SENSOR
SUPPLY
OSCILLATOR
DUTY
CYCLE
A
C
SIGNAL
B
GROUND
AMPLIFIER
THERMISTOR
Adolfo
December 1997
Page:
2
R
I
E
OHM'S LAW
MACHINE ELECTRONICS
Page:
3
BASIC
ELECTRONIC
SIGNALS
• SINE WAVES
• ANALOG SIGNALS
• PULSE TYPE SIGNALS
MACHINE ELECTRONICS
• DC SIGNALS
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4
Fixed Positive
Fixed Negative
0
+ 12V
7V
6V
6V
7V
0
Time
(A)
Varying Positive
Time
(B)
+12V
Positive Pulse
6V
0
0
Time
(C)
Time
(D)
DC
Signals
MACHINE ELECTRONICS
+
- 12V
SINE
WAVES
0
One Hertz
Time
MACHINE ELECTRONICS
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5
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6
ANALOG SIGNALS
0
Pressure ( kPa)
MACHINE ELECTRONICS
DC volts
+
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7
DIGITAL SIGNALS
High
AMPLITUDE
LEVELS
Low
MACHINE ELECTRONICS
TWO DISTINCT
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8
PULSE WIDTH MODULATED
"DUTY CYCLE"
TIME ON vs TIME OFF
+
ON
OFF
ONE PERIOD
MACHINE ELECTRONICS
0
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9
ELECTRONIC
COMPONENTS
Input Devices
Controls
MACHINE ELECTRONICS
Output Devices
Page:
CATERPILLAR MONITORING SYSTEM
769D - 777D OFF-HIGHWAY TRUCKS
10
GAUGE CLUSTER
MODULE
MESSAGE CENTER
MODULE
TACHOMETER
MODULE
1F
ACTION
LAMP
°C kPa MilesKM RPM Liter SERV
CODE
X10
...
ACTION
ALARM
DISPLAY
DATA LINK
INPUT
COMPONENTS
AUTO RETARDER
CONTROL
TRANSMISSION
CONTROL
ENGINE
CONTROL
© 1997 Caterpillar Inc.
INPUT
COMPONENTS
MACHINE ELECTRONICS
CAT DATA LINK
Page:
11
INPUT COMPONENTS
• SWITCHES
• SENSORS
MACHINE ELECTRONICS
• SENDERS
MACHINE ELECTRONICS
Page:
12
MACHINE ELECTRONICS
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13
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14
SENDER-TYPE
• 70 to 800 OHM
MACHINE ELECTRONICS
• 0 to 240 OHM
MACHINE ELECTRONICS
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15
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16
SENSOR-TYPES
FREQUENCY
PWM (DIGITAL)
ANALOG
ANALOG to DIGITAL
MACHINE ELECTRONICS
•
•
•
•
1
2
MACHINE ELECTRONICS
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17
MAGNETIC FREQUENCY
SENSOR
MACHINE ELECTRONICS
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18
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19
TRANSMISSION SPEED
SMALL SIGNALS FROM
SENSING ELEMENT
OUTPUT
ROTATING
GEAR
AMP
AMP
SMALL AC
SQUARE
WAVE
LARGE
SQUARE
WAVE
MACHINE ELECTRONICS
SENSING ELEMENT
('HALL CELL') HALL CELL
IN SLIP HEAD
SMALL
SQUARE
WAVE
REMOVE DC
VOLTAGE
MACHINE ELECTRONICS
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20
MACHINE ELECTRONICS
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21
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22
DIGITAL TEMPERATURE SENSOR
B+
GND
Signal
A
B
C
MACHINE ELECTRONICS
V+
VS
+8
MACHINE ELECTRONICS
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23
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24
ANALOG TEMPERATURE SENSOR
ENGINE
CONTROL
THERMISTER
T
A
C
B
5V
SIGNAL (0 - 5V)
ANALOG
RETURN
MACHINE ELECTRONICS
AMPLIFIER
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25
ANALOG
SECTION
DIGITAL CONVERTER
PWM OUTPUT
TO CONTROL
GROUND
SCHEMATIC
ENVELOPE
DISPLAY
GRAPHICS
MACHINE ELECTRONICS
SIGNAL
V+
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26
OUTPUT COMPONENTS
• Main Display Module
MACHINE ELECTRONICS
• Display Data Link
• Alert Indicators
• Action Lamp/Alarm
MACHINE ELECTRONICS
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27
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28
CATERPILLAR MONITORING SYSTEM
GAUGE CLUSTER
MODULE
TACHOMETER
MODULE
MESSAGE CENTER
MODULE
°C
kPa
Miles
KM
RPM
...
ACTION
LAMP
Liter
SERV
CODE
X10
ACTION
ALARM
CAT DATA LINK
INPUT
COMPONENTS
AUTO RETARDER
CONTROL
TRANSMISSION
CONTROL
ENGINE
CONTROL
INPUT
COMPONENTS
MACHINE ELECTRONICS
DISPLAY
DATA LINK
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29
CATERPILLAR MONITORING SYSTEM
MAIN DISPLAY
FOUR GAUGE
CLUSTER MODULE
ALERT
INDICATORS
ACTION LAMP
P
15
AUT
20
5
25
X100
R
24 V
0
MPH
km/h
44
30
SPEEDOMETER /
TACHOMETER MODULE
MESSAGE CENTER
MODULE
MESSAGE
DISPLAY
MACHINE ELECTRONICS
10
MACHINE ELECTRONICS
OPERATOR MODES
INPUTS
SERVICE
METER
MODE
ODOMETER
MODE
DIGITAL
TACHOMETER
MODE
RESETTABLE
LOAD COUNTER
MODE
DIAGNOSTIC
SCROLLING
MODE
SERV
CODE
41.4
30
(During CRANKING the display will show "P" if the engine is
equipped with the Caterpillar Engine Pre-Lubrication System
If the Ether starting aid is installed an "E" will also appear
during cranking)
MILES or KM
- TOS
170
RPM
- ENGINE SPEED / TIMING SENSOR
700
L
74
- BODY UP SWITCH
(AFTER 10 SECOND ACTIVATION)
SERV
CODE
SERV
CODE
030
MID
Page:
- ENGINE SPEED / TIMING SENSOR
- ALTERNATOR "R" TERMINAL
- ENGINE OIL PRESSURE
271 F05
CID, FMI
Page:
MODULE IDENTIFICATION CODES
31
MID
ELECTRONIC CONTROL
030
036
027
083
Caterpillar Monitoring System (CAT MS)
Advanced Diesel Engine Management (ADEM)
Electronic Programmable Transmission Control (EPTC II)
Automatic Retarder Control (ARC)
FMI
DESCRIPTION
096
177
177
248
263
263
271
271
271
324
324
324
601
819
821
821
830
F03
F04
F08
F02
F03
F04
F03
F05
F06
F03
F05
F06
F08
F02
F03
F04
F08
Fuel LevelSender or Circuit Open or Shorted to Bat +
Torque Converter Temperature Sensor Shorted to Ground (Bat -)
Torque Converter Temperature Signal is incorrect
CAT Data Link Communication Abnormal
8 V Sensor Power Supply Shorted to BAt +
8 V Sensor Power Supply Shorted to ground (Batt -)
Action Alarm or circuit shorted to Bat +
Action Alarm open Circuit
Action Alarm or circuit shorted to ground (Bat -)
Action Lamp or Circuit Shorted to Bat +
Action Lamp Open Circuit
Action Lamp or Circuit shorted to Ground
Brake AIr pressure Sensor signal Incorrect
Display Data Link Error
9V Display Supply Shorted to Bat +
9V Display Supply Shorted to Ground (Batt-)
Brake Oil Temperature Sensor Signal Incorrect
MACHINE ELECTRONICS
CID
Page:
SERVICE MODES
32
HARNESS CODE FOR 769D - 777D OHTs
HARNESS
CODE
NUMERIC
READOUT
SERV
CODE
-1-
34
USE "S" SERVICE SWITCH TO SCROLL GAUGES
C
C
170
-2-
190
GA - 2
GA - 1
SERVICE
kPa
030
MID
-4-
tatle
MILES
UNITS
PERMAMENT
LOAD
COUNT
ECONOMY
SHIFT
(NOT 777D)
-6-7-
L
271 F05
CID FMI
- USE "S" SERVICE
SWITCH TO SCROLL
FAULTS
- USE "C" SERVICE
SWITCH TO CLEAR
FAULTS
- ALL GAUGES AND INDICATORS
SHOW WORST RECORDED CONDITIONS
KM
US
-5-
SERV
CODE
SI
- USE "C"SERVICE SWITCH
TO CHANGE UNITS
1057
-
ON
OFF
- USE "S" SERVICE
SWITCH TO TURN
OFF
- USE "C" SERVICE
SWITCH TO TURN
ON
MACHINE ELECTRONICS
LOG
GA - 4
GA - 3
SERV
CODE
---
-3-
75
715
A11
A12
A13
A14
A15
A16
SERVICE
BRAKE
706-BR
A6
SECONDARY
BRAKE
720-PU
A20
D3
ACTUAL
GEAR
INDICATOR
OR
SCRAPER
CONTROL
A31
A32
A33
A34
A35
733-BR
734-WH
735 - OR
736 - YL
737-GN
B9
B10
893-GN
892-BR
DATA LINK
B1
306-GN
STARTSOLENOID
B2
321-BR
BACK-UPALARM
RELAY
B3
409-OR
NEUTRALOUTTOAUX
NEUTRALOUTTOEMS
B4
891-BU
NEUTRALOUTTOPMC
A5
E767-GN
10
A27
A8
KEY START
SWITCH
307-OR
B5
ENGINE
SPEED
450-YL
CONVERTER
SPEED
452-PU
D996-PU
D997-YL
HARNESS
CODE
A-37PINCONNECTOR
B-10PINSURE-SEALCONNECTOR
2
12
13
3
4
5
6
7
8
9
(DATA LINK)
A29
A30
B6
A18 A36
A22 A24
B7
A17 A19 A37 A9 A10 A21 A23 A25 A26
TRANSMISSION
TOS
GEARSWITCH
TRANSMISSION
AUGERSOLENOID
A4
A3
A5
UP,DOWN,
LOCKUP
SOLENOIDS
EPTC II
SYSTEM
MACHINE ELECTRONICS
708-YL
11
703-BU
704-GY
705-PK
E750-PU
A7
726-BU
707-PU
TRANSMISSION
HOLD (WTS)
SERVICE"SET"&
"CLEAR"SWITCHES
D2
721-BR
722-WH
723-OR
724 - YL
725-GN
BODY UP
D1
710-GN
BODY
RAISE
EPTC II
217-BK
218-BK
219-BK
280 - BK
227-BK
33
711-BR
712-WH
713-OR
714-YL
715-GN
716-BU
709-OR
Page:
SHIFT
LEVER
SWITCH
Page:
EPTC II NORMAL OPERATION
34
SELECT SPEED
(UPSHIFT)
EPTC II
D1
D2
STORE SHIFT
D3
10
SHIFT
LEVER
SWITCH
GND VERIFY
11
2
12
13
3
4
5
6
7
8
CHECK TOS
9
TOS SHIFT
POINT ???
UPSHIFT
NO SHIFT
TRANSMISSION
TOS
GEARSWITCH
TRANSMISSION
GND VERIFY
signal
supply
Exceptions:
1) F-N or R-N shifts only if speed below
5mph.
2) Reverse only if speed below 3mph
3) Upshift one gear in case of
overspeed. L.U. deactivated if in top
gear (3500 OHT)
UP,DOWN,
SOLENOIDS
MACHINE ELECTRONICS
HARNESS
CODE
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35
AUTOMATIC RETARDER CONTROL
KEY FEATURES
SIMPLIFIED RETARDING ON LONG DOWNHILL HAULS
-Maximum truck speed at consistant high engine rpm
- High RPMassuresadequateXMS&brakecooling
-Reducestorquefluctuations,prolongingbrakelife.
PROGRAMMABLE ENGINE CONTROL SPEED
COMMUNICATES THROUGH CAT DATA LINK
ENGINE OVERSPEED PROTECTION
MACHINE ELECTRONICS
AUTOMATIC AND VISIBLE DIAGNOSTICS
Page:
AUTOMATIC RETARDER CONTROL SYSTEM
36
ENGINE SPEED
SENSOR
ENGINE SPEED
HARNESS
CODE INPUTS
SERVICE INPUTS
B6
SET
B7
CLEAR
HARNESS
CODE PLUG
A17-19
36,37
A10
AUTOMATIC
RETARDER
CONTROL
(ARC)
DATA LINK
B9
B10
RETARDER
LAMP
RETARDER LAMP OUTPUT
A5
RETARDER PRESSURE INPUT
A21
ARC ON/OFF
SWITCH
AUTO RETARDER
PRESSURE INPUT
A16
ON INPUT
A3
A11
Diagnostic Display
A26
AIR FROM
SERVICE BRAKE
RESERVOIR
A4
SUPPLY OUTPUT
SUPPLY
SOLENOID
VENT
VENT
CONTROL
SOLENOID
RETARDER
LEVER
AND VALVE
BRAKE
PEDAL
AND VALVE
ARC SHUTTLE
VALVE
AUTOMATIC
RETARDER
VALVE
AUTO RETARDER
PRESSURE SWITCH
SERVICE BRAKE
SHUTTLE VALVE
RETARDER
PRESSURE SWITCH
A - 37 PIN CONNECTOR
B - 10 PIN SURE-SEAL CONNECTOR
TO BRAKE
AIR RELAY
MACHINE ELECTRONICS
OFF INPUT
CONTROL OUTPUT
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37
AUTOMATIC RETARDER CONTROL BOX
Display Mode
1) If no diagnostic code have been
logged, display will show
--2) If diagnostic code have been
logged, display will show a
component number such as
172.
Cont. Failure
Power
When all diagnostic Codes
have been displayed the
display will show END.
1) Access MODE 1 by
activating SERVICE and CLEAR
switches until display shows:
-12) Release switches
10 Pin
3) Activate SERVICE switch to
access diagnostic code to be
cleared.
Ret. Prssr.
Parking Bk.
Throttle
Release the SERVICE switch.
Eng. Speed
Service mode
indicator
Diagnotic
present
AUTOMATIC RETARDER CONTROL
4) Activate the CLEAR switch
to clear the diagnostic code.
5) When all the diagnostic
codes are cleared the display
will show
--To return to MODE 0
Activate both switches
until display shows
-0-
37 Pin
connector
MACHINE ELECTRONICS
ARC Prssr.
followed by a a Failure
Mode Identifier such as F27 To clear logged diagnostics:
MACHINE ELECTRONICS
AETA SYSTEM
50%
Torque Remains
The Same
Torque
50%
50%
Torque
50%
50% Torque
available to wheel
on firm footing
50%
BRAKE SLOWS
SPINNING WHEEL
Page:
38
Page:
Operating Principle
39
Electronic
Control Box
Selector & Proportional
Solenoid Valves
Trans. Output
Sensor
Wheel Speed Sensors
Spring Applied Parking Brakes
MACHINE ELECTRONICS
Standard
Differential
MACHINE ELECTRONICS
LAB EXERCISES
SCHEMATICS QUIZ
Directions: Using the truck electrical schematic given complete the following quiz. Fill in the blanks
or mark the correct answer.
1
Locate the engine coolant sensor on the schematic. List the schematic grid location and the
machine silouette.
2
___
grid location
___
machine location (silouette).
What is the part number of the engine coolant temperature sensor?
_____________
3
What gauge wire s are attached to the sensor in question 2?
a)
14
b)
16
c)
18
d)
20
4.
Locate the start aid switch on the schematic. List the shematic grid location and the machine
silouette.
5.
___
grid location
___
machine location (silouette).
How many wires are attached to the switch in question 8?
a)
2
b)
3
c)
4
d)
5
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40
MACHINE ELECTRONICS
LAB EXERCISES
6.
What are the wire numbers & colours attached to the switch in question 5
__________________________________________________
7.
Briefly explain what a solid red line represents on the schematic.
___________________________________________________________
8.
9.
The ARC displays a CID of 627, the probable malfunction is in the
a)
throttle position sensor
b)
engine RPM sensor
c)
Automatic retarder pressure switch
d)
Parking brake pressure switch
The electronic control displays a FMI of 4, explain the failure description:
___________________________________________________________
10.
At what pressure does the secondary brake pressure switch actuate?
______________________________
11.
Locate the right front strut sensor. What colour is the signal wire?
___________________________________________________________
12.
What does the letter B mean on the machine silhouette?
___________________________________________________________
13.
What is the resistance of the upshift, downshift & LU solenoids ______________
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41