Presentation Objective
At the end of this presentation you will be able to:
•
Describe the benefits of electronically controlled engines.•
Answer basic questions relating to system components.•
Understand the functions of Electronic Technician (ET)•
Describe the basic concept of Controller Area Network (CAN) and SAE J1939.Caterpillar 3000 Series 3054E/3056E
Electronic Control Module (ECM) Manifold Pressure Sensor Intake Air Temperature SensorEngine Oil Pressure Sensor Engine Coolant Temperature Sensor Machine Interface Connector Service Tool Connector (Industrial Engine) Primary Speed/Timing Sensor Bosch VP30 Pump
3000 Series Basic Engine Schematic
Service Tool Connector Intake Manifold Temperature Sensor Intake Manifold Pressure Sensor Primary Speed/Timing Sensor VP30 Electronic Distributor Pump 36-1 Tooth Crank Gear A4 E1 ET Pump ECU VLPM Machine Interface Connector Engine Coolant Temperature Sensor Engine Oil Pressure SensorSystem Components - Wiring Harness
•
Engine harness connects engine mounted sensors and actuators to ECM•
Traditionally wiring and connectors is highest cause of reliability problems•
Incorporates robust sealed connectors•
Connectors are designed for long service life•
Cable insulation is capable of withstanding temperature and fluid exposure•
Outer covering provides protection from damage due to vibration, heat and general abuse•
Harness routing and connector ‘keying’ is used to prevent incorrect connection of componentsElectronically Controlled
Fuel Systems
Caterpillar 3000 Series
Bosch VP30 Fuel Injection Pump
PUMP CONNECTOR Pump Supply/CAN Link/
Engine Speed/Timing/ Fuel Shutoff Connector
Fuel Quantity Solenoid Valve Pump ECU Timing Control Solenoid Secondary Speed/Timing Sensor
TRANSFER PUMP PRESSURE REGULATOR TIMING ADVANCE MECHANISM TIMING SOLENOID FUEL QUANTITY SOLENOID VALVE DELIVERY VALVE INJECTOR SPEED TIMING SENSOR ELECTRONICALLY CONTROLLED FUEL SYSTEM HIGH PRESSURE STAGE LIFT PUMP (PRIMING PUMP) DISTRIBUTOR PLUNGER ENGINE ECM (A4 CONTROLLER) PUMP ECU FUEL RETURN CHECK VALVE CAM PLATE ROLLER RING ROLLER PLATE ORIFICE
A4 ECM (3054E/3056E)
One ECM fits all applications
Basic System - Interactions
CAT DATA LINK Switches/Pushbuttons Sensors: Pressure,Temperature, Speed/TimingINPUTS
Power Supply 12 v or 24 v 5/8 volts sensor supplies and operation Computer Hardware + Software ECMCONTROL
INPUTS
OUTPUTS
Indicator lights Actuators Cables/Connectors Cables/Connectors RelaysOUTPUTS
C.A.N. DATA LINKSystem Components
-ECM Hardware
Analogue voltage PWM PROCESSOR MEMORY OUTPUTS Digital PWM COMMUNICATIONS LINKS INPUTS DigitalElectronic Control Module:
Essential Facts
•
High reliability•
External connectors most vulnerable•
No serviceable parts•
Never replace without full diagnostic test•
All warranty returns checked•
No fault warranty returns - no warranty credit•
ECM is the LAST component you should suspect being faultySensor Types
System Components – Speed Controls
Throttle PositionSensors/Controls
•
Cat Machines- Pulse Width Modulation (PWM) - Set Speed Switches
•
Industrial Engine, pedalposition/operator demand
- Pulse Width Modulation (PWM) - Contacting, resistive track
potentiometer type devices.
• Provide linear voltage output (0.5v to 4.5v)
• Should have idle validation switches on mobile applications for failure detection. Voltage o/p Low Idle High Idle
PWM Throttle Position Sensor
•
Ground•
+8 Volt supply•
PWM OutputSystem Components
-Throttle Position Sensors
•
Pulse Width Modulation (PWM) is an output that is defined by its duty cycle.•
The duty cycle is the relation between the time on to the time off.•
More consistent than a linear sensor type.•
Above 90% and below 10% implies there is an error present.IDLE(0.9volts)
System Components
•
Temperature Sensors: Passive type- Commonly known as magnetic pick-ups - Produce a sinusoidal voltage signal. Signal
conditioning is required in the ECM
•
Pressure Sensors: Active type:- Hall effect
- Produce a ‘conditioned’ square wave signal - More costly than passive sensors
On Engine Sensor Wiring
ECM
14 INTAKE MANIFOLD PRESSURE A B C 1 2 1 2 INTAKE MANIFOLD AIR TEMPERATURE
SENSOR COMMON
26 SENSOR VREF +5 VOLTS
34 SENSOR COMMON O VOLTS
15 ENGINE COOLANT TEMPERATURE
32 INTAKE MANIFOLD AIR TEMP
24 ENGINE OIL PRESSURE
49 CRANKSHAFT POSITION -41 CRANKSHAFT POSITION + 2 1 CRANKSHAFT POSITION + CRANKSHAFT POSITION
-ENGINE OIL PRESSURE SENSOR INTAKE MANIFOLD PRESSURE SENSOR ENGINE COOLANT TEMPERATURE SENSOR INTAKE MANIFOLD TEMPERATURE SENSOR
SPEED AND TIMING SENSOR NO.1 J103 P103 J401 P401 L730 994 X731 995 C967 L731 E965 P1 J1
33 CRANKSHAFT POSITION SCREEN ENGINE COOLANT TEMPERATURE
SENSOR COMMON J100 P100 A B C SENSOR VREF +5V ENGINE OIL PRESSURE SENSOR COMMON
J201 P201
SENSOR VREF +5V INTAKE MANIFOLD PRESSURE SENSOR COMMON
J200 P200
System Components
Temperature Sensors
•
Thermistors:- Semiconductor sensing devices
- Resistance varies with temperature
- Negative Temperature Coefficient (NTC) most common i.e. As temperature increases its resistance
decreases
- 40 to 300ºF range
Temperature Sensors
•
Thermistor Pin No 2 Pin No 1 Ground SignalTemperature Sensors
•
3054E/3056E Applications- Intake Manifold Temperature Sensor
- Engine Coolant Temperature Sensor
System Components
-Temperature Sensors
Volts Ohms (Resistance) Volts Ohms 5.0 25,000 5,000 0.5 Increasing Temperature+5 VOLTS REFERENCE SUPPLY ANALOGUE TO DIGITAL CONVERTER MICR OPR OCESSO R R2 0 VOLTS ECM
Temperature (Passive)
Sensor Operation
R1 TEMPERATURE SENSORSystem Components
-Pressure Sensors
Pressure:
• Active Sensors (i.e. with built in conditioning electronics) provide
analogue voltage output with linear and temperature compensation.
• Various working ranges to suit measured parameter e.g. - 12 to +17 psi (abs) - Atmospheric pressure
0 to 70 psi (abs) - Intake manifold pressure 0 to 115 psi (abs) - Engine oil pressure
Pressure Sensors
Oil Pressure Sensor
Intake Manifold Pressure Sensor A (5 Volts)
B (Sensor Return) C (Signal)
Pressure Sensors
Change of Voltage with Pressure.
Out of range 4.5 Volts 0.5 Out of Range Pressure
+5 VOLTS REFERENCE SUPPLY ANALOGUE TO DIGITAL CONVERTER MICROPROCESSOR 0 VOLTS +12V ECM
System Components
Other Sensors (Industrial):
System Components
Speed/Timing Sensors
• Applications:
- Determine rotational speed and rotational position • Primary - Crankshaft speed and position
• Secondary - Camshaft/fuel pump speed and position
Speed/Timing Sensor
70 Degrees 4 CYL
40 Degrees - 6 Cylinder
Top Dead Center
Rotation
• The 3000 series engines use a 36-1 tooth ring. i.e. the timing ring has space for 36 teeth, and one is missing. The missing tooth allows the ECM to determine the timing of the
engine. The wheel is dowelled to index it to the crankshaft.
System Components - Speed Sensors
Iron Core
Teeth Pole Piece
Passive Speed Sensors
MagnetCoil
Flux Lines
Direction of motion
Secondary Speed/Timing Sensor
Installation
Crank shaft Speed/Timing Sensor ECM (6 cylinder Engine)System Components – Speed/Timing
Sensors
Speed/Timing Sensors – failure Modes
Primary sensor
Defaults to Secondary
Engine runs in “limp home” mode (max 1200 rpm) Engine will start and run with a failed sensor
Secondary sensor
Engine stops and will not start
System Components
-Output Devices
•
Typically include: - Relays - Lamps - Gauges (PWM)System Components - Actuators
Electronically Controlled Fuel Pump•
“Intelligent” rotary pump e.g. Bosch VP30- Local pump mounted ECU controls pump solenoids to achieve desired fuel delivery and timing.
- Main ECM communicates desired timing and fuelling via CAN communication link
Electronic Service Tools
•
Communication Adapter (CA II)
(
CA I can be used if necessary)Electronic Service Tools
CAT ET Service Tool:
• PC based, multi function - Status Screens
- Diagnostics
Electronic Technician
CAT ET
z The first element of STW (Service Technician
Workbench)
z Common for all future Caterpillar electronic engines z Hardware and software required
z Annual subscription
Communication Adapter Group
CAT ET (Electronic Technician)
Functionality includes:z Fault Codes
z Data recording and graphing
z Engine Configuration Horsepower, customer operational parameters, P.T.O. cruise, Multi-position switch.
z Flash Programming (ECM re-programming) z Supports troubleshooting process
z Displays parameters, temperature, speed,
Electronically Controlled Engines
ARE ABLE TO
•
Indicate active faults, logged faults and events•
Identify sensor and actuator short and open circuitsCANNOT
•
Troubleshoot themselvesData Links
z
Cat Data Link (CDL)
z
Controller Area Network (CAN)
Example of CAN wiring
MACHINE INTERFACE CONNECTOR
Ohm TERMINATING
RESISTOR 120 Ohm TERMINATINGRESISTOR
52 61 GEARBOX ECM Address 3 INSTRUMENT PANEL Address 23 ENGINE ECM Address 0 HAND HELD SERVICE TOOL
Address 249 DATA BUS
NODE NODE
Controller Area Networks (CAN)
Introduction:•
CAN is the communication network between intelligent electronic devices used on an application.•
Ground based equipment use a version of CAN that conforms to an international standard known as J1939•
Application control, monitoring and diagnostics is possible using J1939.Controller Area Networks (CAN)
Advantages:•
Uses less wiring, lower weight, lower cost, etc.•
Uses fewer connections, more reliable.•
Easier to install.•
Improved quality of signal.3054E/3056E CAN Data Link Usage
CAN J1939•
Flash ProgrammingCAN Proprietary Data Link
•
ECM to Pump ECU communicationCAN - J1939
Examples of CAN Data link Uses:• ECM to Engine Fuel Pump: Transmits engine power
requirements to pump ECU
• Transmission to Engine: Tells the engine what gear is
currently selected
• Engine to Machine: Broadcasting of engine parameters
(e.g. engine speed, oil pressure, coolant temp.)
3054E Versus 3056E Differences
3054E:
z Cross flow cylinder head z Electric fuel priming pump z Glow plugs for starting
Training Material Resources
z ITIM 3056E Engine – SERV 2705
z Systems Operation Testing & Adjusting z 3054E Industrial Engine – RENR 7568 z 3056E Machine Engine – RENR 2416 z The Service Training website contains:
z Information & this presentation
