Sensores 3500B EUI

Service Training MALAGA

ELECT. ENG. CONTROL 777D

IV. 3500B EUI

Thorben MARCH 1998

ELECT. ENG. CONTROL CHAPTER : 3500B AIR INTAKE AND EXHAUST

This sectional view of the engine shows the injector installation and the pushrod arrangement in relation to the upper portion of the engine. This sectional view is similar to the original 3500 EUI engine. Major differences are the spring loaded injector push rods and the larger diameter camshaft. Each cylinder has three corresponding camshaft lobes. The center lobe is is used to actuate the unit injector. The 3500B has a larger diameter camshaft to accommodate the higher injection pressures generated in the unit injector pumps. The cylinder block has a larger camshaft bore to accommodate the larger camshaft. (All 3500 engines are now being manufactured to this standard.) The 3500B injector pushrod spring, which maintains contact between the lifter roller and the camshaft lobe. This spring is designed to maintain cam follower and camshaft contact and protect the mechanism during a possible overspeed

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ELECT. ENG. CONTROL CHAPTER : 3500B CYLINDER HEADS

MUI

EUI

This picture shows the difference between the Mechanical Unit Injection (MUI) and current Electronic Unit Injection (EUI) installation in the cylinder head. Notice the Helper Spring on the injector pushrod. This arrangement is designed to keep the follower in constant contact with the camshaft. The helper spring is required due to the increased injection pressures of 151 MPa (22000 psi) and the steeper, high lift camshaft lobe profile.

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FUEL PRESSURE REGULATOR

RETURN FUEL

CYLINDER HEAD

PRIMING PUMP SUPPLY

ECM

ELECT. ENG. CONTROL

FUEL TANK

FUEL TRANSFER PUMP

CHAPTER : 3500B

PRIMARY FUEL FILTER

SECONDARY FUEL FILTERS (2 MICRON)

FUEL SUPPLY SYSTEM 992G

DIFFERENTIAL PRESSURE SWITCH

ELECT. ENG. CONTROL CHAPTER : 3500B FUEL SUPPLY SYSTEM

SECONDARY FILTER

FUEL PRESSURE REGULATOR

ECM TRANSFER PUMP FUEL TANK PRIMARY FILTER FUEL TANK

This view shows the injector and its fuel supply circuit. A larger volume of fuel passes through the injector than is required for injection. This extra flow is used to cool the injector, which is also surrounded by coolant.

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RIGHT TURBOCHARGER EXHAUST TEMPERATURE SENSOR

LEFT TURBOCHARGER EXHAUST TEMPERATURE SENSOR

COOLANT FLOW SWITCH

FUEL FILTER DIFFERENTIAL PRESSURE SWITCH

LOW OIL LEVEL SWITCH

AFTERCOOLER TEMPERATURE SENSOR

COOLANT TEMPERATURE SENSOR

SPEED/TIMING SENSOR

8/12/16 INJECTORS

P84/J84

J23/P23

P30/J30

P41/J41

J25/P25

J47/P47

P31/J31

RIGHT TURBOCHARGER INLET PRESSURE SENSOR

J28/P28

J106/P106

J29/P29

LEFT TURBOCHARGER INLET PRESSURE SENSOR

J27/P27

J105/P105

FAN SPEED SENSOR

A/C ON SWITCH

ENGINE FAN CONTROL SOLENOID

CRANKCASE PRESSURE SENSOR

24 V

R

1 0

MPH km/h

15

25 X100

20

30

RELAY

+ BATTERY

113-OR

AUT

15 AMP BREAKER

CYLINDER

GROUND LEVEL SHUTDOWN SWITCH

KEY START SWITCH

24 V

BATTERY

P

44

ELECTRONIC SERVICE TOOL CONNECTOR

USER DEFINED SHUTDOWN

ETHER START VALVE

ENGINE

308-YL

DISCONNECT SWITCH

MONITORING SYSTEM

0

5

+ BATTERY

J35/P35

GROUND BOLT

APPLICATION BLOCK DIAGRAM

TO PRELUBRICATION PUMP

STARTING AID SWITCH

THROTTLE BACK-UP SWITCH

THROTTLE POSITION SENSOR

J1

TURBOCHARGER OUTLET PRESSURE SENSOR

ATMOSPHERIC PRESSURE SENSOR

FILTERED OIL PRESSURE SENSOR

J22/P22

J32/P32

UNFILTERED OIL PRESSURE SENSOR

J48/P48

J3/P3 MACHINE INTERFACE CONNECTOR

GROUND BOLT

J2

ECM

CAT Data Limk

J21/P21

P20/J20

J4/P4 THROUGH J19/P19

P26 T/C CONNECTOR

BASIC ENGINE BLOCK DIAGRAM

ELECT. ENG. CONTROL

CHAPTER : 3500B

COMPONENT DIAGRAM - 777D

ELECT. ENG. CONTROL CHAPTER : 3500B ANALOG SENSOR POWER SUPPLY

J21 P21

ENGINE COOLANT TEMPERATURE SENSOR

+V ANALOG ANALOG RETURN SIGNAL

A B C

FILTERED OIL PRESSURE SENSOR

+V ANALOG ANALOG RETURN SIGNAL

P22 J22 A B C

TURBO OUTLET PRESSURE SENSOR

+V ANALOG ANALOG RETURN SIGNAL

P23 J23 A B C

RIGHT TURBO INLET PRESSURE SENSOR

+V ANALOG ANALOG RETURN SIGNAL

A B C

ATMOSPHERIC PRESSURE SENSOR

+V ANALOG ANALOG RETURN SIGNAL

P27 J27 A B C

LEFT TURBO INLET PRESSURE SENSOR

+V ANALOG ANALOG RETURN SIGNAL

P28 J28 A B C

CRANKCASE PRESSURE SENSOR

+V ANALOG ANALOG RETURN SIGNAL

P43 J43 A B C

P1 J1 36 30

ECM +V ANALOG SUPPLY ANALOG RETURN

P25 J25

5 ± 0.5 VOLTS

P48 J48

UNFILTERED OIL PRESSURE SENSOR

+V ANALOG ANALOG RETURN SIGNAL

A B C

The Analog Sensor Power Supply provides power to all the analog sensors (pressure and temperature). The ECM supplies 5.0 ± 0.5 Volts DC (Analog Supply) through the J1/P1 connector to each sensor. A power supply failure will cause all analog sensors to appear to fail. The power supply is protected against short circuits, which means that a short in a sensor or a wiring harness will not cause damage to the ECM.

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ELECT. ENG. CONTROL CHAPTER : 3500B DIGITAL SENSOR POWER SUPPLY

THROTTLE POSITION SENSOR

J35 P35

+V DIGITAL DIGITAL RETURN SIGNAL

A B C

FAN SPEED SENSOR +V DIGITAL DIGITAL RETURN SIGNAL

P1 J1 29 35

ECM + V DIGITAL SUPPLY - V DIGITAL RETURN

J84 P84 A B C

8 ± 0.5 VOLTS LEFT EXHAUST TEMPERATURE SENSOR +V DIGITAL DIGITAL RETURN SIGNAL

RIGHT EXHAUST TEMPERATURE SENSOR +V DIGITAL DIGITAL RETURN SIGNAL

J30 P30 A B C

J31 P31 A B C

The ECM supplies power at 8 ± 0.5 Volts through the J1/P1 connector to the following circuits: - Throttle Position Sensor - Fan Speed Sensor (if installed) - Exhaust Temperature Sensors The power supply is protected against short circuits, which means that a short in a sensor will not cause damage to the ECM

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

SYSTEM POWER SUPPLIES The 3500B EUI system has one external and five internal power supplies with various voltages as shown. EXTERNAL POWER SUPPLIES ECM power supply

24 Volts

INTERNAL POWER SUPPLIES Speed/Timing Sensor power supply

12.5 Volts

Injector power supply

105 Volts

Analog Sensor power supply

5 Volts

Digital Sensor power supply

8 Volts

Wastegate Control Solenoid power supply 0 - 24 Volts

ECM Power Supply The power supply to the ECM and the system is drawn from the 24-Volt machine battery. The principle components in this circuit are: - Battery - Key Start Switch - Main Power Relay - 15 Amp Breaker - Ground Bolt - ECM Connector (P1/JI) - Machine Interface Connector (J3/P3) If the supply voltage exceeds 32.5 Volts or is less than 9.0 Volts, a diagnostic code is logged. (See the Troubleshooting Guide for complete details on voltage event logging.) NOTE: The Ground Bolt and the Machine Interface Connector are the only power supply components mounted on the engine.

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

Injector Power Supplies The injectors are supplied with power from the ECM at 105 Volts. For this reason, precautions must be observed when performing maintenance around the valve covers. On the 3512B and 3516B, two of the internal power supplies are used for the injectors. If a failure occurs, only one bank of injectors could have failed. On the 3508B, only one of the internal power supplies is used. As previously mentioned, the same ECM is used on all three configurations. If an open or a short occurs in the injector circuit, the ECM will disable that injector. The ECM will periodically try to actuate that injector to determine if the fault is still present and will disconnect or reconnect the injector as appropriate.

Speed/Timing Sensor One Speed/Timing Sensor is installed and it serves four basic functions in the system: - Engine speed detection - Engine timing detection - Cylinder and TDC identification - Reverse rotation protection The ECM supplies 12.5 ± 1 Volts to the Speed/Timing Sensor. Connector pins A and B transmit the common power supply to the sensor. The C connector pin transmits the signals from the sensor to the ECM. This power supply is not battery voltage, but is generated and regulated within 1.0 Volt by the ECM. This power supply and the Speed/Timing Sensor are vital parts of the EUI system. A failure of the sensor will result in an engine shutdown.

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

The Speed/Timing Sensor is mounted on the rear housing and is self-adjusting during installation. This type of sensor does not have a typical fixed air gap. However, the sensor is not in direct contact with the timing wheel, but does run with zero clearance. A Speed/Timing Sensor failure will cause an engine shutdown. The sensor may be functionally checked by cranking the engine and observing the service tool status screen for engine rpm. A sensor failure will be indicated by the active fault screen on the service tool. An intermittent failure will be shown in the logged fault screen. The sensor has a dedicated power supply. A power supply failure at the ECM will cause the sensor to fail. The sensor head is extended prior to installation. The action of screwing in the sensor pushes the head back into the body after the head contacts the timing wheel. During installation, it is essential to check that the sensor head is not aligned with a wide slot in the timing wheel. If this condition occurs, the head will be severed when the engine is started, and some disassembly may be necessary to remove the debris. Timing calibration is normally performed after the following procedures: 1. ECM replacement 2. Speed/timing sensor replacement 3. Engine timing adjustment 4. Camshaft, crankshaft or gear train replacement

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

The engine Coolant Temperature Sensor is located at the front of the engine on the thermostat housing. This sensor is used with the ECM to control various functions. The following systems or circuits use the Temperature Sensor output to the ECM: The Vital Information Management System (VIMS) or Caterpillar Monitoring System Coolant Temperature Gauge over the CAT Data Link. The High Coolant Temperature Warning Alert Indicator and Gauge on the VIMS or Caterpillar Monitoring System panel. (The information is transmitted over the CAT Data Link.) The Engine Demand Fan Control, if installed, uses the sensor signal reference to provide the appropriate fan speed. The Cat Electronic Technician (ET) status screen for coolant temperature indication. The Cold Mode engine control (i.e. elevated low idle and timing reference for cold mode operation). The Ether Aid control as a reference for Ether Aid operation. The sensor supplies the temperature signal for the following functions: - Caterpillar Monitoring System or VIMS instrument display, warning lamps and alarm - Demand Control Fan (if so equipped) - ET or ECAP coolant temperature display - High coolant temperature event logged above 107°C (225°F) - Engine Warning Derate when 107°C (225°F) is exceeded or low oil pressure occurs (if so equipped) - Reference temperature for Cold Mode operation NOTE: All analog sensors use the common analog power supply of 5.0 ± 0.2 Volts.

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

The Aftercooler Temperature Sensor is mounted at the rear of the block (Off-highway Truck) and measures coolant temperature in the aftercooler circuit. The ECM uses the sensor signal as a reference for the fan control. When high aftercooler temperatures are reached, the cooling fan speed is increased. Very high aftercooler temperatures will cause a VIMS warning event to be logged. NOTE: This sensor measures the ability of the aftercooler to cool the air sufficiently for combustion. As a general rule, for every 1 degree that the combustion air is reduced in temperature, the exhaust will be reduced by approximately 3 degrees. High inlet manifold temperatures can significantly shorten the life of exhaust system components (i.e. exhaust manifolds, valves, turbochargers and pistons).

Three pressure sensors are used for the measurement of oil pressure: - Two Oil Pressure Sensors (filtered and unfiltered) - Atmospheric Pressure Sensor The filtered and unfiltered pressure sensors are used together to measure oil filter restriction. The filtered oil pressure sensor is used to measure lubrication oil pressure for the operator on the dash panel and for the technician on ET. The atmospheric pressure sensor is used with this oil pressure sensor to calculate the gauge pressure reading.

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ELECT. ENG. CONTROL CHAPTER : 3500B

340

49.3

320

46.4

300

43.5

280

40.6

260

37.7

240

34.8

220

31.9

200

29

180

26.1

160

23.2

140

20.3

120

17.4

100

14.5

80

11.6

OIL PRESSURE IN PSI

OIL PRESSURE IN kPa

OIL PRESSURE MAP

8.7

60 600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

ENGINE RPM kPa x 0.145 = PSI

Engine oil pressure varies with engine speed. As long as oil pressure increases above the upper line after the engine has been started and is running at low idle, the ECM reads adequate oil pressure. No faults are indicated and no logged event is generated. A delay built into the system prevents false events from being logged after start-up or after a filter change. If the engine oil pressure decreases below the lower line, the following occurs: - An event is generated and logged in the permanent ECM memory. - A Category 3 Warning (alert indicator, action lamp and alarm) is generated on the VIMS and Caterpillar Monitoring System. - The engine is derated (if so equipped) to alert the operator. The width of the pressure band between the two lines is sufficient to prevent multiple alarms and events or a flickering warning lamp. (This pressure separation is referred to as hysteresis).

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

The Atmospheric Pressure Sensor is installed on the ECM mounting adapter and is vented to the atmosphere. This sensor has various functions which are fully described later in the presentation. Briefly, it performs the following functions: Ambient pressure measurement for automatic altitude compensation and automatic air filter compensation. Absolute pressure measurement for the fuel ratio control, ET, filter restriction, and Caterpillar Monitoring System panel (gauge) pressure calculations.

All pressure measurements require the atmospheric pressure sensor to calculate gauge pressure. All pressure sensors in the system measure absolute pressure. The sensors are used individually in the case of atmospheric pressure (absolute pressure measurement). They are used in pairs to calculate gauge pressures (oil and boost) and filter restriction. All the pressure sensor outputs are matched to the Atmospheric Pressure Sensor output during calibration. Calibration can be accomplished automatically using the ET service tool or by turning on the key start switch without starting the engine for five seconds. The Atmospheric Pressure Sensor performs four main functions: 1. Automatic Altitude Compensation (Maximum derate 24%) 2. Automatic Filter Compensation (Maximum derate 20%) 3. Part of the pressure calculation for gauge pressure readings 4. Reference sensor for pressure sensor calibration A foam filter is installed below the sensor to prevent the entry of dirt.

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ELECT. ENG. CONTROL CHAPTER : 3500B ENGINE POWER DERATING MAP

100%

7,500

98%

8,210

96%

8,920

94%

9,630

92%

10,340

90%

11,050

88%

11,760

86%

12,470

84%

13,180

82%

13,890

80%

14,600

78%

15,310

76%

16,020

74%

16,730

72%

17,440 77

76

75

74

73

72

71

70

69

68

67

66

65

64

63

62

61

60

59

58

57

56

55

54

ALTITUDE IN FEET

PERCENT OF FULL LOAD POWER

ACCORDING TO ATMOSPHERIC PRESSURE

53

ATMOSPHERIC PRESSURE IN kPa

Atmospheric pressure measurement by the sensor provides an altitude reference for the purpose of Automatic Altitude Compensation. The graph shown here describes how derating on a typical 3500B starts at 7500 ft. and continues linearly to a maximum of 17000 ft. Other engines may start between 4000 and 12000 ft. depending on the application. The advantage of the EUI system is that the engine always operates at the correct derating setting at all altitudes. The system continually adjusts to the optimum setting regardless of altitude, so the engine will not exhibit a lack of power or have smoke problems during climbs or descents to different altitudes. NOTE: The EUI system has an advantage over a mechanical fuel system which is derated in "altitude blocks" (i.e. 7500 ft., 10000 ft., 12500 ft.). EUI derating is continuous and automatic. Therefore, a machine operating in the lower half of the block is not penalized with low power. Conversely, a machine operating in the upper half of the block will not overfuel with the EUI system.

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

The Turbocharger Inlet Pressure Sensor is mounted between the air filter and the turbocharger. This sensor is used in conjunction with the atmospheric pressure sensor to measure air filter restriction for engine protection purposes. The difference between the two pressure measurements is used as the filter differential pressure. The engine ECM uses this calculation to determine whether derating is necessary to protect the engine against the effects of excessive filter restriction. This function is referred to as Automatic Air Filter Compensation. Depending on the application and air intake system configuration, either one or two Turbocharger Inlet Pressure Sensors may be used. If the machine is equipped with an ether start system, the ECM will automatically inject ether from the ether cylinders) during cranking. The operator can also inject ether manually with the ether switch in the cab. Ether will only be injected if the engine coolant temperature is below 10°C (50°F) and engine speed is below 1200 rpm.

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

Automatic Filter Compensation means that the engine is protected against the effects of plugged filters. Derating is automatic as follows: - Air filter restriction (∆P) exceeds 6.25 kPa (30 in. of water) - Engine power derating starts at the rate of 2% per 1 kPa of ∆P - Maximum derate 20% - Event is logged when air filter restriction (∆P) exceeds 6.25 kPa (30 in. of water) These ∆P specifications are typical examples. The actual values may vary depending on the application. Derating is retained at the maximum ∆P until the key start switch is cycled off and on. NOTE: If only one filter is plugged, the ET service tool and Caterpillar Monitoring System will display the highest ∆P of the two. Derating is also based on the highest ∆P of the two.

The Turbocharger Outlet Pressure Sensor measures absolute pressure downstream of the aftercooler. Boost (gauge) pressure can be read with the service tools. This measurement is a calculation using the Atmospheric Pressure and the Turbocharger Outlet Pressure Sensors. A failure of this sensor will cause the ECM to default to a zero boost condition. This failure can result in a 60% loss in engine power. The function of the sensor is to enable the Air/Fuel Ratio Control which reduces smoke, emissions and maintains engine response during acceleration. The system utilizes manifold pressure and engine speed to control the air/fuel ratio. Engine fuel delivery is limited according to a map of gauge turbo outlet pressure and engine speed. The Air/Fuel Ratio Control setting is adjustable on 3500B machine applications using the service tool.

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

The ECM uses gauge pressure measured from the Crankcase Pressure Sensor and the Atmospheric Pressure Sensor to determine whether crankcase pressure is excessive (i.e. a piston allowing excessive blowby which could soon cause considerable damage). The ECM will warn the operator of possible damaging conditions and record adverse conditions in the memory. A possible cause of excessive crankcase pressure could be piston damage or a piston ring failure. An early warning means that the engine can be shut down without catastrophic secondary damage. Crankcase pressure is compared with atmospheric pressure. The result is crankcase (gauge) pressure (i.e. pressure above ambient). The trip points are: WARNING EVENT

2 kPa (10 in. of water) 3.5 kPa (17in. of water)

A Crankcase Pressure Sensor is mounted on the right side of the engine.

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

Two Exhaust Temperature Sensors are installed on the 793C. The sensors are mounted between the exhaust manifold and the turbocharger. The ECM uses the sensors to warn the operator of possibly damaging conditions and logs an event in the memory. An engine derate occurs on Off-highway Trucks if excessive exhaust temperatures are reached.

The Throttle Position Sensor provides engine speed control for the operator. At engine start-up, the engine rpm is set to low idle for two seconds to allow an increase of oil pressure before the engine is accelerated. The Throttle Position Sensor receives 8 Volts from the Digital Sensor Power Supply at the ECM. The Throttle Position Sensor is shown on the machine wiring side of the diagram. NOTE: This system eliminates all mechanical linkage between the operator's engine speed controls and the governor (ECM).

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

Demand Fan Controls Two types of thermostatic fans are used in 3500B machine applications. Some Off-highway Trucks and Track-type Tractors are equipped with a variable speed fan drive clutch. Some Wheel Loaders are equipped with a hydraulic fan drive. Both systems use the ECM and the temperature sensor as the engine coolant temperature reference, and both are controlled by the ECM. If an electrical failure of the system occurs, the fan will go to maximum (100%) speed. The advantages of the systems are: - Reduced fuel consumption in most conditions - Reduced engine overcooling at low ambient temperatures - Faster engine warm-up - More engine power available at the flywheel - Reduced noise

Engine Mounted Switches Three EUI circuit switches are mounted on the engine: The Low Oil Level Switch signals the ECM if the engine oil level decreases below a predetermined level. The ECM then warns the operator of possible damaging conditions and logs an event. The Filter Differential Pressure Switch signals the ECM if the pressure across engine fuel filter is excessive and the filter needs to be changed. The Coolant Flow Switch provides the operator with a warning if a failure in the coolant circuit causing no flow occurs. The switch contacts are normally open with no flow. The Coolant Flow Switch, like the Oil Level Switch, is a passive sensor (i.e. no power supply) which means that the ECM cannot determine if the switch or associated circuit has failed. A system problem could be determined if coolant flow is indicated with the engine stopped or if no coolant flow is indicated with the engine running. The functions of these switches may be checked using the status screen. The Coolant Flow Switch should indicate if flow is present. This function should be checked both with the engine running and stopped.

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

The Throttle Back-up Switch provides a "limp home" mode in the event that the Throttle Position Sensor becomes inoperative. If the ECM detects either an invalid or no signal, the Throttle Back-up Switch is automatically activated. When activated, the operator may operate the switch to raise the engine speed to 1200 rpm for as long as the switch is operated. If the Throttle Position Sensor signal is received again, the switch is deactivated.

Engine Shutdown Systems The Ground Level Shutdown Switch is connected to the ECM through the machine and engine wiring harnesses. The switch signals the ECM to cut electrical power to the injectors, but maintains power to the ECM. This feature also enables the engine to be cranked without starting for maintenance purposes. No other circuits may be connected to this system. The user defined shutdown feature may be used in conjunction with other circuits. The User Defined Shutdown feature (if installed) may be used to connect another device to the system to shut down the engine (such as a customer installed fire suppression system). When the shutdown input is grounded for one second, the engine will stop running. The input must be pulled down below 0.5 Volts before the ECM will recognize the shutdown signal. Operation of the User Defined Shutdown is logged as an event and can also be shown on the ET status screen. For example, when installed on an Off-highway Truck, this feature is programmed to function only during the following conditions: Parking brake is ENGAGED Transmission is in NEUTRAL Machine ground speed is at zero Not all machines will have this feature installed

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ELECT. ENG. CONTROL CHAPTER : 3500B COMPONENT DIAGRAM

Ether Injection System The ECM controls the use of ether for cold starting. The ECM uses inputs from the speed/timing and coolant temperature sensors to determine the need for ether. The ECM cycles the ether for three seconds on and three seconds off. Actual flow is determined by engine speed and temperature. Ether injection is disabled when the coolant temperature exceeds 10°C (50°F) or engine speed exceeds 1200 rpm. A manual mode allows ether injection when the above parameters permit. In the manual mode, a continuous flow of ether is injected. The ether injection status can be read on the ET status screen.

Prelubrication System The ECM controls the prelubrication system. This system uses the coolant temperature, engine speed and oil pressure as its references to determine the need for prelubrication. The system is activated when the key start switch is turned to the start position. The system prevents starter motor engagement until the oil pressure increases.

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ELECT. ENG. CONTROL CHAPTER : 3500B LOGGED EVENTS

Logged events listed on the appropriate ET screen are conditions which are abnormal to the operation of the engine. For example: - High coolant temperature - Low oil pressure - Filter restriction - Excessive engine speed

These events are not normally electronic problems, but might be conditions caused by a plugged radiator, low oil level, maintenance or operator deficiencies. A list of possible events for the 3500B engine is included on the next page. Some of the parameters listed in this presentation are used in the ET events list. They are as follows: - High coolant temperature - High exhaust temperature - High aftercooler temperature - Crankcase pressure - Loss of coolant flow - Low (lubrication) oil pressure (according to the oil pressure map) - User defined shutdown - Air filter restriction - Fuel filter restriction - Oil filter restriction - Engine oil level - Engine overspeed histogram - High boost - Low boost

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ENGINE ELECTRONIC CONTROL MODULE (ECM)

SERVICE TOOL CONNECTORS

CAT DATA LINK LAPTOP COMPUTER

IMPLEMENT CONTROL MODULE

COMMUNICATION ADAPTER

CAT ELECTRONIC TECHNICIAN

ELECT. ENG. CONTROL

CHAPTER : 3500B

3F

POWERTRAIN CONTROL MODULE

DATA LINK DIAGRAM (992G)

VIMS

Page: 26 GAUGE CLUSTER MODULE

SERVICE LAMP

SERVICE KEYSWITCH

VIMS RS-232 PORT

SPEEDOMETER/ TACHOMETER MODULE

MAIN MODULE

KEYPAD MODULE

3F VIMS SERVICE TOOL AND SOFTWARE

ELECTRONIC TECHNICIAN (ET) DISPLAY DATA LINK

VIMS

MESSAGE CENTER MODULE

VIMS ONLY INTERFACE MODULE

CAT DATA LINK

ACTION LAMP CAT DATA LINK SENSORS

VITAL INFORMATION MANAGEMENT SYSTEM (VIMS)

SENSORS SENSORS

IMPLEMENT CONTROL ECM TRANSMISSION CONTROL ECM

ELECT. ENG. CONTROL

ACTION ALARM

CHAPTER : 3500B

ADEM II CONTROL

VIMS DIAGRAM (992G)

VIMS/VIDS INTERFACE MODULE

KEYPAD DATA LINK

ELECT. ENG. CONTROL CHAPTER : 3500B TIMING CALIBRATION

TIMING WHEEL

REFERENCE EDGE TO TDC DISTANCE REFERENCE EDGE

ASSUMED CYL. NO. 1 TDC +7°

-7° TIMING CALIBRATION SENSOR SIGNAL

±7°

ACTUAL CYL. NO. 1 TDC

TIMING REFERENCE OFFSET

MAXIMUM TIMING REFERENCE OFFSET ± 7 DEGREES

As the Speed/Timing Sensor uses the timing wheel for a timing reference, timing calibration improves fuel injection accuracy by correcting for any slight tolerances between the crankshaft, timing gears and timing wheel. During calibration, the offset is saved in the ECM EEPROM (Electrically Erasable Programmable Read Only Memory). The calibration offset range is limited to ± 7 crankshaft degrees. If the timing is out of range, calibration is aborted. The previous value will be retained and a diagnostic message will be logged. The timing must be calibrated after performing the following procedures: 1. ECM replacement 2. Speed/timing sensor replacement 3. Timing wheel replacement 4. Camshaft, crankshaft or gear train replacement

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ELECT. ENG. CONTROL CHAPTER : 3500B E -TRIM CODE READING

TRADE MARK

PART No.

TRIM CODE

SERIAL No.

SERIAL No. BAR CODE

The code identifies the discharge and timing characteristics of the injector and is programmed into the ECM. If the injector is replaced, the new code must be entered via ET’s calibration menu. Old injectors are not coded, the default code 1100 must be entered.

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ELECT. ENG. CONTROL CHAPTER : 3500B E-TRIM FEATURE

CAT Electronic technician - Calibrations Select Calibration Pressure Sensor Calibration Injector Code calibration Timing Calibration Injector Injector Injector Injector Injector Injector Injector Injector Injector

1 2 3 4 5 6 7 8

Code 1100 1100 1100 1100 1100 1100 1100 1100

Change ENGINE 3508B ALL ENGINES BUILD STARTING MAY 15, 1996 HAVE THE E-TRIM FEATURE ON THEIR PERSONALITY MODULE AND INJECTORS CODED WITH AN E-TRIM CODE THE SOFTWARE COMPENSATES FOR INJECTOR VARIATION IN TIMING AND DISCHARGE. THE E-TRIM IS A 4 DIDGIT CODE ETCHED ON THE INJECTOR TAPPET IF IT IS NOT POSSIBLE TO REPROGRAM AN INJECTOR CODE IMMEDIATELY THE ENGINE WILL NOT BE SEVERELY HARMED , ALTHOUGH IT SHOULD BE REPROGRAMMED AS SOON AS POSSIBLE TO OPTIMIZE ENGINE PERFORMANCE AND PREVENT ANY LONG TERM DETRIMENTAL EFFECTS

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ELECT. ENG. CONTROL CHAPTER : 3500B COLD MODE TIMING

TO WARM MODE

TIMING ADVANCE BTDC

HIGH ENGINE SPEED

LOW ENGINE SPEED

FIXED TIMING

30° C

50° C

60° C

COOLANT TEMPERATURE IN DEGREES FAHRENHEIT

Cold Mode The desired timing is retarded during Cold Mode operation based on coolant temperature and engine speed. 1. For coolant temperatures at or below 86°F: Timing will be retarded to protect the engine against high cylinder pressures. Idle is elevated to 1300 rpm (with parking brake ON and transmission in NEUTRAL). 2. For coolant temperatures above 86°F and below 140°F, the timing will advance. For engine speeds below 1200 rpm, timing will vary according to the low engine speed line. NOTE: Neither fuel nor engine speed is limited during Cold Mode operation. When cold mode operation is deactivated, the desired timing returns to normal operation.

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ELECT. ENG. CONTROL CHAPTER : 3500B FRC OFFSET

VALID NUMBERS -25 to +25

+25

-25 0 Acceptable response Clean exhaust

© 1994 Deneba Systems, Inc.

LESS SMOKE SLOWER RESPONSE

© 1994 Deneba Systems, Inc.

MORE SMOKE FASTER RESPONSE

The Fuel Ratio Control has been optimized to provide excellent performance and black smoke control without any need for adjustment. There should be no need to use the “Fuel Ratio Control Offset” except for special circumstances.

Changing the Fuel Ratio Control Offset parameter allows the customer tailoring of the fuel to air ratio in order to compensate for winter blend fuel, individual costumer preference etc.

Use of the Fuel Ratio Control Offset parameter will NOT affect overall power output of the engine. The parameter should NOT be used to mask possible engine performance which may exist.

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ELECT. ENG. CONTROL CHAPTER : 3500B COLD START LOGIC

In cold mode the ECM stops injection to non-firing injectors until the engine has reached a certain temperature (coolant temperature).

The ECM cuts out each cylinder for a brief amount of time to see if that injector is contributing to power. If not injection will be stopped to that cylinder. TheECM will retest any cutout cylinder (injector) every so often to see if it started to fire or not.

HELPS REDUCE WHITE SMOKE DURING ENGINE WARM UP

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