12_Cummins iscOKservman manual traducir español.pdf

8/19/2019 12_Cummins iscOKservman manual traducir español.pdf

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All subjects related to maintenance and repairs to the diesel

engines are covered in the engine manual furnished by the

engine manufacturer. The instructions issued by the engine

manufacturer should be followed at all times. The local Cummins

dealer is capable and dedicated to performing warranty repairs

and any other services required. Contact your local Cummins

dealer on any questions related to engine performance or

problems.

It is advisable to obtain the necessary electronic test equipment

and trim the technicians that will be involved in servicing this

engine.

Special attention should be given to operating and servicing the

engine if operating in an environment involving severe cold

weather or extreme dusty conditions.

The electronically controlled ISC engine is a major step in

extended engine service life, reduced maintenance and

operating costs, and reduces problems created by driver error orabuse. The brain of the engine is the Electronic Control Module

(ECM) located on the left side of the engine.

Engine Data Plates

Three data plates are located on the engine. The information

listed on these plates are critical when ordering replacement

TL960 SERVICE MANUAL

Page 12-1

Cummins ISC

Engines



parts or discussing service related problems with your area

Cummins service facility.

1. Engine Data Plate

This data plate, located on top of the engine front cover,contains the engine serial number (ESN) and a Control

Parts List (CPL) number. The ESN and CPL are required

when ordering parts. The engine serial number is

stamped in the engine block above the oil cooler housing.

2. Fuel Injection Pump Data Plate

The Fuel Injection Pump Data Plate is located on the side

of the fuel injection pump and contains the pump serial

number, part number, and factory code.

3. ECM Data Plate

This plate contains the ECM part number and serialnumber, engine serial number date code, and a code that

identifies the software number that tells how the ECM is

programmed.

Electronic Control Module

The command center for the operation of the engine is the ECM.

The ECM assimilates signals from various sensors on the

engine and transmission. Based on these signals, the ECM

modifies fuel flow to the injectors as necessary to control thevarious functions under its control. Some of these are:

Low Idle Speed •Engine Timing •Diagnostics

•Fast Idle Speed •Accelerator Interlock •Start-up & Emissions

•Top Engine RPM •Cruise Control •Top Road Speed

•Engine Protection System •Fuel Economy •Fault Detection

These are discussed briefly herein, however, they may be more

in-depth in the Operation and Maintenance Manual 3666242.

Some of the functions of the ECM are programmed into the ECM

by Cummins and cannot be changed. Others are programmed in

accord with the customer's requirements. In all cases, special

software and electronic service tools are required to make any

changes.


Page 12-2



Top Engine RPM

The ISC 215 and 250 hp, low torque engines are governed at

2400 rpm. All other high horsepower engines are governed at

2200 rpm.

One of the functions of the engine protection system is to reduce

rpm and torque in the event of a problem with engine oil

pressure, engine overheat, or high intake air temperature. Then

such a problem occurs the ECM reduces fuel to the injectors,

causing a power loss that is obvious to the driver and at the

same time causes a warning light to come "ON" on one of the

four warning lamps on the dash.

Vehicle Top Speed Limit

Maximum road speed is preset at the factory, based on tire size,

rear axle ratio, and the customer's request. This cannot be

altered in the field without special software and electronic

service tools.

As the bus approaches the top speed limit fuel to the injectors

will be be limited, causing a drop off of power within three (3)

mph of the limit. Full power will be restored when road speed

drops three (3) mph. The driver will notice the power drop offgradually as top speed is approached.

Engine Protection System

The ECM receives signals sent from sensors monitoring oil

pressure, coolant temperature, and intake air temperature.

The sensor monitoring intake air temperature is located in the

pipe between the CAC and the turbocharger. The coolant sensor

is just below it, in the top radiator pipe. The oil pressure sensoris located in the block, just below the fuel/water filter.

If any one of these systems fall below, or rises above its normal

operating range, the ECM will cause the YELLOW warning light

to flash. This alerts the driver of a potential problem. If the RED

stop lights comes on the driver should pull off the road as soon

as possible to prevent damage to the engine.


Page 12-3

Caution : If the RED

warning light comes onwhile the bus is moving, thedriver should pull the bus offthe road as soon as possibleto avoid damage to theengine.



When the YELLOW light begins flashing, engine power may

drop off depending on the severity of the problem. At the same

time, the ECM will file a diagnostic fault code in its memory. This

can be retrieved by using the diagnostic switch or by using

Cummins "INSITE" electronic service tool.

Engine Low Idle and Fast Idle RPM

Low idle of 700 rpm is set at the factory. Fast idle is set at 1000

rpm, both controlled by the ECM.

The ECM will cause the engine to shut down after a period of

idling and there has been no movement of the bus or of the

accelerator pedal. This period can be anywhere between five

minutes or 30 minutes, depending on the period determinedwhen the ECM was programmed. Thirty seconds before the

engine shuts down, the yellow light on the dash will flash. If the

operator wants the engine to continue idling, simply touch the

accelerator pedal or the brake pedal. Once this is done, the

automatic shutdown is no longer functional until the bus has

been moved.

The idle shut down system will not function if the coolant

temperature is below 1000 F (380 C).

Start-up and Emission Control

The ECM controls the operation of the two (2) grids heaters in

the intake manifold. The grid heaters heat the intake air to aid in

cold weather starting, and at the same time reduce white smoke

after starting.

The ECM controls the preheat operation by sensing signals sent

from the sensor in the radiator top pipe and from the sensor

installed in the pipe between the CAC and the turbocharger. Formore information on this refer to the Air Intake section of this

manual.

The Wait-to-Start light comes on at the same time the heater

grids are energized. No attempt to start the engine while this

light is on should be made. Remember as soon as the starter is

engaged the intake heater grids are deenergized by the ECM.


Page 12-4



After the engine starts, the heaters operate on and alternating

basis until the bus reaches a road speed of 19 mph, or for three

(3) minutes.

Cruise Control

Refer to the Cruise Control comments in the Electrical section of

this manual.

Your area Cummins dealer can provide the needed literature,

test equipment, and training for the technicians. The dealer is

well qualified to handle warranty repairs as well as any other

engine service.

ECM Diagnostic System

The ECM controls a built-in diagnostic system that alerts the

driver of a system problem by illuminating one of the warning

lamps on the dash. It also records the fault code(s) that may

appear.

Ignition Switch On, Diagnostic Switch Off, Engine Not

Running

With the ignition switch on and Diagnostic switch off, the ECMperforms diagnostic and status operations. The dash indicator

lamps (RED-stop, YELLOW-warning, Water-in-Fuel, and Wait-

to-Start) will illuminate for two (2) seconds, one after the other, to

verify they are in working order. This is a normal part of the

power-up sequence. If an active fault is present, one of the

lamps will remain lighted for a short period of time and then

begin flashing.

Ignition Switch On, Diagnostic Switch On, Outboard

Diagnostic Mode

In addition to alerting the driver of a problem while the bus is

moving, the four (4) lamps are also used in the diagnostic

operation.

With ignition on and diagnostic switch on, the YELLOW lamp will

flash at the beginning of a fault code sequence, then the RED


Page 12-5

Note : If no active fault isrecorded, both the RED andYELLOW lamps will comeon and stay on.



lamp will flash a 3-digit code for the active fault.

If a fault code is recorded, the following sequence will occur:

1. The YELLOW warning lamp will flash.

2. A short 1-2 second pause.3. The 3-digit fault code will flash on the RED lamp, with a

short 1-2 second pause in between each number.

4. When the number has finished flashing in RED, the

YELLOW lamp will appear again and the 3-digit code will

repeat in the same sequence.

The lights will flash each code two (2) times before advancing to

the next code, if one exists.

If only one code is recorded, the system will continuously showthe same code.

When not using the diagnostic system make sure the diagnostic

switch is OFF. If left ON during normal operation, the ECM will

not record some fault codes.

Throttle Control

Fuel flow to the cylinders is controlled by the Electronic Control

Module (ECM), which receives a signal from a Throttle PositionSensor (TPS) mounted on the back side of the accelerator

pedal. The ECM supplies 5 volts as input voltage to the pedal

sensor. This voltage will vary in output back to the ECM,

depending on the position of the accelerator pedal.

An Idle Validation Switch (IVS) is a part of the TPS assembly. It's

purpose is to advise the ECM when the accelerator pedal is, or

is not, at the idle position. The function of the IVS is to provide a

fail-safe in the event of a stuck-open throttle or a failure in the

throttle wiring or circuits. In the event such a failure occurs, theECM will cause the engine to idle only-it will not accelerate. At

the same time one of the fault codes relating to the IVS system

will appear on the dash instrument. Codes 431, 432, and 551

relate to the IVS system.

At this point, enough emphasis cannot be placed on the

procurement of the necessary test tools, which are available


Page 12-6



from your area Cummins dealer, Cummins Troubleshooting

Manual #3666194-00, and proper training for the technicians

that will be involved in servicing the electronic systems on all

current and future bus purchases.

To eliminate unnecessary and costly repairs it is important to

procure the test equipment mentioned in the first paragraph in

the part covering the testing of the throttle position sensor. Your

Cummins dealer will be anxious to help you obtain what you

need for the Cummins engines.

Calibrating the Throttle Position Sensor

Calibrating the throttle sensor is a simple event, and will have to

be done anytime the sensor is replaced, or the sensor leadshave been disconnected with the ignition switch ON, or if the

ECM has been replaced.

This is accomplished by turning the ignition switch ON, and

slowly depressing the pedal to FULL throttle, from complete

IDLE, three times. Release the pedal completely after each

pedal movement.

Replacement of the sensor assembly is simple, also. Remove

the two screws from the side of the sensor, disconnect thesensor harness at the connectors found in the compartment

behind the left windshield wiper door.

Throttle Position Sensor Test Procedure

The most efficient way to test the TPS is to use the Cummins

INSITE program, which makes use of an IBM PC (or 100%

compatible) and the Inline Adapter Kit. These are a part of the

service tools required to properly service/diagnose fault codes

that will occasionally appear. Instructions for checking thevarious sensors and circuits are included in the INSITE package,

which is available for your area Cummins dealer.

If this equipment is not available, you can use a multimeter and

service harness #3823255, which is available from your local

Cummins dealer.


Page 12-7





Testing the Idle Validation Switch

If using the multimeter instead of the Cummins INSITE program

to test the Idle Validation Switch (IVS), procure test leads

#3823995 and #3823996 from your area Cummins dealer.

Test Procedure (See Figure 1.)

1. Disconnect IVS connector from chassis harness located

in the compartment behind the left windshield wiper door.

Install test harness into IVS connector (from accelerator

pedal).

2. With pedal in IDLE (closed) position, measure the

resistance between pins 'A' and 'B'. Meter should register

125 ohms or less.3. Depress pedal to FULL throttle position, this value should

read infinite ohms (100K ohms or more).

4. With pedal in IDLE position, check resistance between

pins 'B' and 'C'. Should read infinite ohms.

5. Depress pedal to FULL throttle position, value should be

between 20 and 125 ohms.

If the above resistance values are not within the specifications

outlined, the IVS is defective and the complete sensor assembly

should be replaced.

If the IVS passes the above tests, it may still be necessary to test

for a short to ground.

1. Connect negative (-) lead of multimeter to a metal part of

the pedal assembly.

2. Connect the positive (+) meter lead to pin 'C' and then to

pin 'B'. Meter should show an open circuit, or 100K ohms

or more. If not within these specifications, replace the

IVS/TPS assembly.

Pages 19-64 through 19-69 in the Cummins Troubleshooting

Manual #3666194-00 go into much more detailed instructions in

troubleshooting the IVS system.


Page 12-9

Figure 1





Engine Removal Procedure

1. Observe all steps mentioned above.

2. Remove engine compartment door, if a fork lift is to be

used to remove the engine.3. Remove body rear bumper.

4. Remove chassis rear bumper.

5. Remove chassis upper support crossmember

6. Remove radiator module assembly. See the Cooling

section for removal instructions.

7. Remove hoses and pipes between charge air cooler and

engine. Tag the intake air temperature sensor connector.

8. Remove exhaust pipe from turbocharger.

9. Remove the metal elbow (turbo inlet air) from the turbo (to

avoid damage during engine removal.)10. Remove upper and lower radiator pipes. Tag the coolant

temperature sensor connector to insure it goes back onto

the coolant sensor.

11. If bus is equipped with air conditioning, remove A/C drive

belt.

12. Remove heater hoses from shut-off valves.

13. Disconnect oil pressure hose at oil filters.

14. Disconnect cables and wiring from 200 or 270-amp

alternators.

15. Disconnect fuel lines at rear of engine. Tag them to besure they go back onto the correct fitting.

16. Disconnect hydraulic supply hose at hydraulic pump.

17. Disconnect power steering pressure hose at union at rear

of engine.

18. Disconnect compressor main discharge hose from copper

tubing, same area.

19. Remove transmission dipstick support clamp at hydraulic

reservoir.

20. Disconnect D-1 governor air line.

21. If bus is equipped with a retarder, remove the retarder

cooler and hoses from the chassis. If no retarder,

disconnect the oil cooler hoses at the transmission.

22. Disconnect transmission temperature sensor lead.

23. Disconnect transmission wiring harness:

a. Disconnect speedometer sensor at rear of

transmission.

b. Disconnect speed sensor lead at lower front corner of

transmission.


Page 12-11

Note : We recommendpulling the radiator for 2reasons: 1) It will probablybe sent out for cleaning if anew engine is to beinstalled. 2) Removal

provides greater access tothe wiring, connectors,hoses, etc. on the left side ofthe engine.

Note : If smaller alternators(120-160 amp) are on the

engine, consider removingthe alternator mounting boltsand pull the alternatorforward for easier access tothe wiring.

Caution : Carefully

observe to see that all

connections, hoses, wiring,etc. have beendisconnected.



c. Separate transmission main harness at the

connector.

d. Remove transmission main harness support clip, top

of transmission.

24. Disconnect drive line from transmission, tie it up out of theway.

25. Disconnecting the various cables, harnesses, connectors

on the left side of the engine requires some study since

they are bundled together. The following suggestions are

offered in an effort to simplify this task as much as

possible.

a. Remove all cables and wiring from the starter. Tag

each as to which post it is to be reinstalled.

b. Cut all tie wraps that bind the harnesses, etc.

together.c. Disconnect the chassis harness connector to the

ECM.

d. Remove harness support clip at front of engine.

e. Disconnect intake heater grid cables at the grids.

f. After the tie wraps have been removed, separate the

cables, hose, etc. that will stay with the chassis from

those that go to the electrical modular compartment.

When separated, move the entire harness over the

top of the engine to the opposite side of the chassis.

Tie up out of the way.

26. Remove rear motor support bolts.

27. Remove front motor support bolts.

28. Place transmission jack beneath transmission, making

sure the oil pan is not damaged and the transmission sit

firmly on the jack.

29. The engine has a lifting eye at front and rear of the

cylinder head. Place engine lift bar or chain in place,

connect it to a floor hoist or fork lift. Take weight off the

motor supports.

30. Remove engine front support crossmember from the

chassis.

31. With adequate assistance, gently pull the

engine/transmission from the chassis. Carefully observe

to see that all wiring, air lines, hoses, etc. have been

disconnected.

32. After removal place assembly on a stable, secure

platform or mount to the perform removal of accessories,

fittings, etc.


Page 12-12

Caution : Do NOT

disconnect any of theCummins suppliedconnectors. They arepainted the color of theengine.



Once the assembly has been removed and safely mounted on

supports, everything connected to and with the package is now

easily accessed. Depending on the repairs to be made, it may

not be necessary to remove many of the accessories. If a

replacement engine is to be installed, it is a simple matter totransfer these items to the new engine as they are removed. All

components should be installed in the same position as

removed.

If this engine has over 250,000 miles, consider replacing or

rebuilding the alternator, starter, power steering pump, and air

compressor at this time, if they have not been replaced before.

If the radiator has not been cleaned, consider flushing it at this

time.

Engine Installation

If a new or exchange engine is to be installed, place it alongside

the engine removed to facilitate transferring components, hoses,

and harnesses. Make sure these items are positioned exactly as

removed. This will aid in installing the new engine, as well as

minimizing changes once the engine is in place.

Bind the hoses and harnesses together on the left side of theengine and secure them to minimize interference as the engine

assembly is moved into the chassis.

1. With the engine and transmission secure on the jack and

lift, move the assembly into position to go back into the

chassis.

2. With adequate assistance move the assembly back into

place in the chassis.

3. Install the engine front support crossmember. Torque

Grade 8 mounting bolts in accord with the torque chartshown.

4. Inspect engine mount isolators for condition, (replace if in

doubt).

5. At this point the most critical area of installation is the

correct routing of hoses and harnesses to prevent chafing

and fretting. Pull the main harness back into place and

make the electrical connections in accord with the tags


Page 12-13

Bolt Size Torque Value

3/4-103/4-165/8-11

5/8-181/2-131/2-20

280 ft/lbs.320 ft/lbs.170 ft/lbs.

180 ft/lbs.80 ft/lbs.90 ft/lbs.



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