Use of 8T5200 Signal Generator/Counter Group{0778, 0783, 0785} Caterpillar

The 8T5200 Signal Generator/Counter Group includes the 8T5201 Signal Generator with the necessary cables and adapter needed to make the tool operational. The 8T5201 Signal Generator is a small, hand held, square wave generator that can be used to simulate speed for troubleshooting transmission electronic control units. (A magnetic pickup will not be needed.) An 8 Volt square wave "OUTPUT" connection is provided for this purpose.

The 8T5201 Signal Generator can also be used as a calibrator for most electronic diagnostic tools that now use the 5P9698 Calibrator. A 3 Volt square wave "CAL OUT" connection is provided for this purpose. The frequency (Hz) range is approximately 3-7000 Hz, infinitely variable, by turning the "Hz" adjustment knob. In addition, the 8T5201 Signal Generator can be used as a frequency (Hz) counter when the input is a pulsating DC or AC signal of .1 to 50 Volts maximum.

8T5200 Signal Generator/Counter Group Components

1 6V2198 Extension Cable.

2 6V3072 Case.

3 Instruction Form SEHS8579.

4 6V6045 Accessories Case.

5 Form SEHS8009 Accessories Case Decal.

6 8T5112 Signal Input Cable.

7 8T5197 Calibrator Cable and Adapters.

8 Adapter [Part of Cable (6)].

9 8T5198 Transmission Adapter Cable.

10 Adapter [Part of Cable (6)].

11 8T5267 Foam Block.

12 8T5201 Signal Generator/Counter. Decal SEES5688 (not shown) Operation Instructions on Rear of Signal Generator/Counter. Decal SEES5689 (not shown) Carrying Case Label.

Additional Service Parts for use with the 8T5201 Signal Generator/Counter are:

8T5199 Front Panel Membrane Switch Assembly.8T0844 Front Plastic Cover.6V3110 Back Plastic Cover.8T1005 LCD Display.8T0887 Display Connector Assembly.

An optional accessory that is available for use with the 8T5200 Signal Generator/Counter Group is the 6V6152 Adapter. The 6V6152 Adapter is used with the 8T5200 Signal Generator/Counter Group when it is necessary to check a 6V6113 Amplifier. See the information in this instruction.

Another optional accessory that is available for use with the 8T5200 Signal Generator/Counter Group is the 9W6370 Harness. The 9W6370 Harness is used with the signal generator/counter group to make a functional check and/or calibration check for two and three element electronic speed switches.

Features Of The 8T5200 Signal Generator/Counter Group

Hz DISPLAY:

Hz (Hertz or frequency) is directly displayed on a liquid crystal digital (LCD) display in numbers that are 12.7 mm (.5") high. The display is visible in direct sunlight and also in low-light conditions.

OUTPUT/OFF/ON:

When it is necessary to disconnect the output signal, use the OUTPUT/OFF switch. This permits the internal oscillator to continue running but output will be "0". This helps to maintain a steady frequency when the signal is again connected with the OUTPUT/ON switch. The LCD OUTPUT/OFF indicating arrow is visible when the output signal is disconnected and the readout will be blank.

FREQUENCY RANGES HI/LO:

The LO range switch permits easy selection of any frequency from 3-300 Hz. The HI range switch permits easy selection of any frequency from 40-7000 Hz. The specific range will be indicated with an arrow on the readout. If the maximum frequency in each range becomes lower than normal, it is an indication that the batteries are nearing the end of their useful life.

OFF/ON SWITCH:

This switch turns power ON or OFF to the signal generator/counter from either internal battery power or from transmission electronic control power. If any indicating arrows or digits are visible on the readout, it is an indication that signal generator/counter power is ON.

POWER:

When the signal generator/counter is used as a calibrator or a frequency counter, power is supplied by internal batteries. When the signal generator/counter is used in place of a magnetic pickup, power is supplied from the transmission electronic control.

EXT. PWR:

If voltage to the signal generator/counter is 9.0 V or greater when it is connected to the transmission electronic control, the LCD arrow adjacent to EXT. PWR will be visible.

INPUT:

Input is provided for connection of an external frequency of 10-19999 Hz, between .1-50 volt peak.

OUTPUTS:

Two outputs are provided for the transmission electronic control, and for use as a calibrator: one is a 0-8 Volt dc coupled square wave, and the other is a 3 Volt P-P ac coupled square wave.

CALIBRATION:

The signal generator/counter is designed to maintain its original accuracy for the life of the instrument so no adjustments are necessary. Accuracy can be checked, however, by connection of a 5P9698 Calibrator to the INPUT connection on the 8T5201 Signal Generator/Counter. Set the calibrator at 1600 Hz. The frequency shown on the LCD display of the signal generator/counter must be the same as the frequency selected on the calibrator, ± 1.

LOW BATTERIES:

A LO BAT indicator is visible on the LCD display when the batteries need replacement. Two 9 Volt alkaline batteries are needed. These batteries will give approximately 80 hours of operation. When battery replacement is necessary, refer to the topic entitled BATTERY INSTALLATION in this publication.

OVERRANGE:

With a voltage input of 1 to 50 Volts, the normal range of the counter is 1-9999 Hz. Overrange is from 10,000 to 19,999 Hz, and is so indicated by an overrange indicating arrow along the side of the LCD. The counter can count higher than 19,999, but the LCD can not display a higher reading. A further explanation of this is given in USING THE 8T5201 SIGNAL GENERATOR/COUNTER AS A FREQUENCY COUNTER, in this instruction.

Specifications

Connections And Controls For 8T5201 Signal Generator/Counter

(1) OUTPUT CONNECTOR: Connection for the 6V2198 Extension Cable and the 8T5198 Transmission Adapter Cable that connects the square wave signal from the 8T5201 Signal Generator/Counter to the transmission electronic control. Also used to connect voltage from the transmission electronic control to power the 8T5201 Signal Generator/Counter.

(2) Hz ADJUSTMENT KNOB: By releasing the knob brake and turning the knob, the frequency, in cycles/second, or Hertz (Hz) of the signal generator/counter can be changed to the desired display reading.

(3) INPUT CONNECTOR: This connection, with the 8T5112 Input Cable, permits the 8T5201 Signal Generator/Counter to be used as a frequency or Hertz (Hz) Counter.

(4) CAL OUT CONNECTOR: This connection is used when the unit is to be used as a calibrator. Use the 8T5197 Calibrator Cable and adapters to connect the unit to be calibrated to the 8T5201 Signal Generator/Counter.

(5) DIGITAL READOUT: A four and one-half digit display will give a reading on any frequency from 1 to 19999 Hz, as long as voltage is greater than 1 Volt, and less than 50 Volts peak.

(6) OUTPUT/ON SWITCH: If the signal to OUTPUT and CAL OUT is disconnected by pushing OUTPUT/OFF Switch (11), push OUTPUT/ON Switch (6) to connect the signal.

(7) HI SWITCH: Push this switch when a signal of 40-7000 Hz is needed. Maximum frequency will be lower when the batteries are getting near the end of their useful life.

(8) ON SWITCH: Push this switch to turn power ON to the signal generator/counter.

(9) OFF SWITCH: Push this switch to turn power OFF to the signal generator/counter.

(10) LO SWITCH: Push this switch when it is necessary to accurately adjust in the low frequency range from 3-300 Hz. Maximum frequency will be lower when the batteries are getting near the end of their useful life.

(11) OUTPUT/OFF SWITCH: Push this switch to disconnect the signal to OUTPUT and CAL OUT, but still permit the internal oscillator to continue operation. To again connect the signal to OUTPUT and CAL OUT, push OUTPUT/ON Switch (6).

Operation Instructions

1. When the signal generator/counter is used as a counter for any signal that is less than 1 Hz, LCD display (1) may be blank except for an indicator arrow at the side of the display. There can also be a flashing 1 on the display [illustration (A)]. (The voltage level of the signal must be 1V-50V maximum.)

2. The unit is equipped with an automatic overrange indicator. An indicator arrow along the bottom of the LCD display can be seen after a display of 9999 Hz. Any time the overrange indicator arrow is visible, it is an indication the reading may not be correct, unless it is known that the input signal is not more than 19,999 Hz [illustration (B)].

3. When the unit is used as a signal generator, or a calibrator [illustration (C)], the display reading can be from 3-7000 Hz, except when OUTPUT/OFF Switch (2) is pushed. This will disconnect the signal from the internal oscillator and cause LCD display (1) to go blank. Arrow (3) at the left of the LCD display can be seen, indicating that the OUTPUT/OFF switch has been pushed.

4. Illustration (D): The signal generator/counter is connected to the 6V2198 Extension Cable (4) and 8T5198 Transmission Adapter Cable (5). The unit is in the "HI" Range and displaying 2959 Hz.

5. Illustration (E): The signal generator/counter is connected to the 8T5197 Calibrator Cable (6) and shown set at 50 Hz in the "LO" Range.

6. Adapters (7) and (8) can be used to connect diagnostic tools to cable (6).

Use Of The 8T5201 Signal Generator/Counter To Check Transmission Electronic Control

It is possible to dynamically test the transmission electronic control and its connecting solenoids and wiring harnesses. When doing these tests, the vehicle engine will be operating at LOW IDLE during the entire test. All shift solenoids and wiring harnesses must operate correctly for good operation. These components are also checked during the dynamic test procedure.

Pretest Procedure

1. Read the POWER TRAIN TESTING AND ADJUSTING section (Electrical System) of the Service Manual for the specific machine that is to be tested. Take special notice of all Warnings, Notes, etc.

2. Block all wheels and apply the parking brake to keep the machine from moving during the test procedure.

3. For trucks, tractors and scrapers, remove both axles. As an alternate to this on 769C Trucks disconnect the output drive shaft.

Optional Pretest Procedure

If there is only one person to do the test procedure, and an open area is available for the machine, the procedure is optional.

1. Read the POWER TRAIN TESTING AND ADJUSTING section (Electrical System) of the Service Manual for the specific machine that is to be tested. Take special notice of all Warnings, Notes, etc.

2. Disconnect the wiring harness at the lockup clutch solenoid on the following machines: 631E, 633E, 637E, 769C, 773B, 777A, 777B and 785.

3. For 651E and 657E remove both axles to disconnect the transmission from the final drive.

NOTE: On 651E and 657E there is no lockup clutch solenoid, therefore, both axles must be removed.

4. Block the machine wheels and apply the parking brake to keep the machine from moving during the test procedure.

Show/hide table

Never permit the machine to move during a test. If the machine is moving while using the 8T5201 Signal Generator to simulate speed to the transmission electronic control, engine overspeed and/or severe personal injury may result due to an unexpected downshift.

Test Procedure

1. Do the necessary steps shown in the PRETEST PROCEDURE and/or the OPTIONAL PRETEST PROCEDURE as it applies to the machine that is to be tested. See the POWER TRAIN TESTING AND ADJUSTING section (Electrical System) of the Service Manual.

2. Loosen and move shield (1) from around transmission magnetic pickup (2), and disconnect wiring harness from magnetic pickup. Use 6V2198 Extension Cable (3) and 8T5198 Transmission Adapter Cable (4) to connect 8T5201 Signal Generator/Counter (5) to transmission speed magnetic pickup wiring harness (6) instead of transmission magnetic pickup.

3. Turn the disconnect switch and key switches to ON position, but do not start the engine. (This supplies electrical power to the transmission electronic control.)

4. Turn ON the signal generator/counter; set to HI range and adjust the unit to the low end of the range (40 Hz or less). Check to make sure that EXT PWR arrow (7) is visible on the LCD display. (When the arrow is visible, it is an indication that there is at least 9.0 Volts available from the transmission electronic control to provide electrical power to operate the signal generator/counter. During normal operation, the transmission electronic control provides power to operate the transmission speed magnetic pickup.)

5. Operate then release the following: transmission HOLD pedal (scrapers); bed RAISE lever (truck); transmission test switch (tractors). Check to make sure that all transmission control indicator lights (LED's) light up. (If the LED's do not light up, refer to the Service Manual.)

6. Put transmission shift lever in NEUTRAL position.

NOTE: Be sure to block the machine wheels and activate the parking brake.

7. Start the engine and let it operate at LOW IDLE for the entire test. Keep a close check on torque converter oil temperature during the test. Do not permit torque converter oil to overheat. Let brake air pressure increase to full pressure on the brake air pressure gauge. Apply the service brake pedal and hold throughout the complete test.

8. Move the transmission shift lever to its highest gear. The transmission must shift into first or second gear according to the machine being tested. Make sure the transmission control indicator lights light up, and give the correct indication.

9. Slowly increase the frequency (signal) on the signal generator/counter, and check the indicator lights (LED's) for a correct indication as the transmission upshifts through each gear.

a. After the highest gear is reached, move the shift lever to a gear position that is two or three gears lower. The transmission must not downshift. (This is a check of the downshift inhibit function.)

b. Return the transmission shift lever to the highest gear position.

10. Slowly decrease the frequency on the signal generator/counter, and check the indicator lights (LED's) for a correct indication as the transmission downshifts through the gears.

11. When the signal generator/counter returns to the low end of the range (40 Hz or less), the transmission will be in FIRST gear except for: 651E, 657E, 621E, 623E and 627E. On these machines, the transmission will be in SECOND gear. Move the shift lever to NEUTRAL position.

a. Move transmission shift lever to REVERSE position. The transmission must shift to the REVERSE position.

b. Move transmission shift lever to NEUTRAL position. The transmission must shift to NEUTRAL position.

12. The final test is for the reverse speed inhibit. Increase the frequency of the signal generator/counter to approximately 1500 Hz.

a. Move the transmission shift lever to REVERSE position. The transmission must NOT shift to REVERSE gear.

b. Move the transmission shift lever to the NEUTRAL position and turn off the signal generator/counter. This completes the dynamic test of the transmission electronic control and its connecting components. For further troubleshooting information, refer to the Power Train Testing and Adjusting Section (Electrical Group) of the specific Service Manual.

13. Stop the engine and disconnect the signal generator/counter. Connect the wiring harness to the transmission speed magnetic pickup and the lockup clutch solenoid. See Steps 2 and 3.

14. Install the drive axles to connect the transmission and final drives.

15. Install lockwire at all locations where it is required.

NOTE: If the transmission did not shift correctly during the test, the problem may be insufficient oil flow or oil pressure for the transmission. It is permissible to increase the engine low idle speed, but low idle speed must never be more than 1000 rpm.

Use Of The 8T5201 Signal Generator/Counter As A Calibrator

The 8T5201 Signal Generator/Counter can be used as a calibrator in place of the 5P9698 Calibrator. Typical applications are as follows.

NOTE: When used as a calibrator, the 8T5201 Signal Generator/Counter operates from two internal alkaline batteries. Battery life is approximately 80 hours; when the unit is not in use, turn it off. A "LO BAT" indication will appear on the LCD display when battery replacement is necessary. Refer to the topic entitled BATTERY INSTALLATION in this publication.

Checking The Magnetic Operation Of The 6V2100 Multitach

1. Get a copy of Special Instruction Form SEHS7807, "Using the 6V2100 Multitach and 6V3121 Multitach Group".

2. See the topic "Checking Magnetic Operation".

3. Turn the power source switch for the multitach to ON.

4. Program the number 60 into P/REV instead of using number 10.

5. Using the 8T5197 Cable (1) and the correct adapter from the accessories case, connect the 8T5201 Signal Generator/Counter (2) to the "MAG IN" on the multitach (3). Make sure the multitach is in "MAG" mode.

6. Push ON button (4) to turn on 8T5201 Signal Generator/Counter. Push HI button (5) for frequency range. Between 60 and 4000 Hz the display on both the signal generator/counter, and the display on the multitach should read the same, within ± 1.

Hold Source Feature Of The 6V4060 Engine Set Point Indicator

1. Install a 6V2100 Multitach on the set point indicator. See the topic "CHECKING THE MULTITACH HOLD SOURCE FEATURE", in Special Instruction Form SEHS7931.

2. Connect power to the set point indicator (with multitach attached); see "CONNECTION OF POWER TO THE SET POINT INDICATOR" in Special Instruction Form SEHS7931.

3. Program the multitach for 60 P/REV (instead of 10).

4. Use 8T5197 Calibrator Cable (1) and the correct adapter to connect 8T5201 Signal Generator/Counter (2) to the MAG MULTITACH INPUT on the set point indicator.

5. Push the ON button to turn on 8T5201 Signal Generator/Counter, then push HI for frequency range.

6. Adjust the signal counter/generator to 2400. The readout display on both the signal generator/counter and the multitach should indicate the same number within ± 1.

7. Do the remainder of the procedure as given in "CHECKING THE MULTITACH HOLD SOURCE FEATURE" as given in Special Instruction Form SEHS7931.

Calibration Of 8T5250 And 6V50 Engine Timing Indicator

NOTE: For 6V50 Engine Timing Indicator, refer to the topic CALIBRATION PROCEDURE in Special Instruction Form SEHS8135, "ELECTRONIC REPAIR OF 6V3100 ENGINE TIMING INDICATOR".

1. Refer to the topic CALIBRATION USING A FREQUENCY COUNTER, and use 8T5201 Signal Generator/Counter (1) in place of the frequency counter. Use 8T5112 Signal Input Cable (2) to connect the unit that is to be calibrated to the INPUT connection on signal generator/counter (1).

2. In the alternate procedure, CALIBRATION USING A 5P9698 CALIBRATOR, the 5P9698 Calibrator must be used for these adjustments. The calibration procedure cannot be done with total accuracy if the 8T5201 Signal Generator/Counter is used as a replacement for 5P9698 Calibrator.

Checking The 6V6113 Amplifier From The 6V4950 Injection Line Speed Pickup Group

1. Refer to the topic, CHECKING THE 6V6113 AMPLIFIER in Special Instruction Form SEHS8029.

2. Follow the instructions given within the above topic except, use 6V6152 Adapter Plug (1) and 8T5197 Calibrator Cable (2) to connect CAL OUT on 8T5201 Signal Generator/Counter (3) to 6V6113 Amplifier (4). (8T5201 Signal Generator/Counter is being used instead of 5P9698 Calibrator.)

3. Turn on the power and set the 8T5201 Signal Generator/Counter to exactly 25 Hz, with no change on the LCD reading.

4. Program the multitach P/REV number for 30. (The multitach will display 50 ± 1 rpm instead of 3000 rpm.)

5. Do the remainder of the procedure as given in CHECKING THE 6V6113 AMPLIFIER.

Operational Checks

The 8T5201 Signal Generator/Counter can be used instead of the 5P9698 Frequency Calibrator to perform an operational check of the 5P3600 Hydraulic Flow Meter, or the 1P5500 Photo Tach. Connect the 8T5197 Calibrator Cable, with the correct adapter, to the CAL OUT connection. Use the Special Instruction Form, for the unit being tested, to perform the operational check. If an accurate calibration is needed, use the 5P9698 Frequency Calibrator for the calibration procedure.

Using The 8T5201 Signal Generator/Counter As A Frequency Counter

1. Connect 8T5112 Cable (1) to the input connection on the 8T5201 Signal Generator/Counter (2).

2. Push the ON switch to turn on power to the 8T5201 Signal Generator/Counter.

3. Connect a signal source, as shown, (pulsating DC or AC) to the 8T5112 Cable, from 10-19999 Hz and from .1 V-50 Volt maximum. The display will read the input signal ± 1 Hz.

NOTE: The readout can display from 1-19999, but the Overrange Arrow will be visible for readings from 9999 to 19999 Hz. This should be remembered when it is known that the reading will be in the 9999-19999 Hz range. The counter has the capacity to count above 19999, but cannot display a higher number. Any reading above 19999 will be displayed as a number between 10,000 and 19,999, i.e., a reading of 24550 Hz will be displayed as 14550 Hz, and the overrange arrow will be visible.

4. Since the 8T5201 Signal Generator/Counter uses internal batteries, turn it OFF when it is not in use. Battery life expectancy is approximately 80 hours on the two alkaline batteries. A "LO BAT" indication will appear on the display when it is necessary to replace the batteries. For battery replacement, refer to the topic entitled BATTERY INSTALLATION in this publication.

Operational Check of 8T5201 Signal Generator/Counter

1. Signal Generator/Counter (1) must be removed from the carrying case, and the batteries must also be installed. See BATTERY INSTALLATION.

2. Push ON Switch (2) to turn power ON for the signal generator/counter. An arrow should be visible at LO on the LCD display. A number between 1 and 400 should also appear on the LCD display. (It will take several seconds for the display to stabilize.)

3. If the LO BAT indicator is visible on the LCD display, or the LCD display is blank, install new batteries. Refer to the topic entitled BATTERY INSTALLATION. Make sure the polarity is correct when the new batteries are installed.

4. Release the brake for Hz Adjustment Knob (3) and turn the knob while watching the numbers on the LCD display. Each turn of knob (3) in a clockwise (cw) direction should cause the numbers on the LCD display to increase. Each turn of knob (3) in a counterclockwise (ccw) direction should cause the numbers on the LCD display to decrease. With Hz adjustment knob (3) at the low end of the range (completely CCW) the LCD display should not be blank. At this position, LO range should display 3 Hz or less, and HI range should display 40 Hz or less.

NOTE: If the numbers do not appear and change as stated, see the topic REPAIR OF 8T5200 SIGNAL GENERATOR/COUNTER GROUP in this instruction.

5. Refer to pages 3, 4, 5 and 6 in this instruction and check for correct operation of the signal generator/counter.

Battery Installation

Battery installation for the 8T5201 Signal Generator/Counter is as follows:

1. Remove the six screws from the back cover of the signal generator/counter.

2. Separate the back cover from the front cover. If there are batteries in the unit, remove them.

3. Clean the battery contacts inside the signal generator/counter.

4. Install two new 9 Volt alakaline batteries. Be sure that battery polarity connections are installed correctly in the signal generator/counter.

5. Install the back cover of the signal generator counter and tighten the six screws securely.

Repair Of 8T5200 Signal Generator/Counter Group

If the signal generator/counter does not operate correctly, remove the back cover of the unit and check to make sure the batteries are in good condition and installed correctly. If the unit still does not operate correctly, it can be returned to the Caterpillar Service Technology Group. Enclose a letter with the returned unit stating the operational problem and the date of purchase from Caterpillar. Units that are less than 1 year old will be repaired under warranty (except for abuse). The cost of out-of-warranty repairs will be charged to the owner. For repair work (warranty or non-warranty) of the 8T5200 Signal Generator/Counter, return it to: