DIAGNOSTICS OF TRANSMISSION HYDRAULIC CIR- CUITS, TRAVEL CLUTCH AND ELECTRONIC CONTROL UNIT OF PROXIMA POWER TRACTOR

Transcription

1 DIAGNOSTICS OF TRANSMISSION HYDRAULIC CIR- CUITS, TRAVEL CLUTCH AND ELECTRONIC CONTROL UNIT OF PROXIMA POWER TRACTOR

2 TABLE OF CONTENT 1 DESCRIPTION OF DISTRIBUTOR DESCRIPTION OF INPUTS, OUTPUTS AND THREADED JOINTS BASIC DISTRIBUTOR SCHEME PRELIMINARY WORKS BEFORE MEASUREMENT ELECTRIC WIRING INSPECTION DIAGNOSTICS OF HYDRAULIC CIRCUITS OF TRANSMISSION BEFORE MEASUREMENT: RULES FOR MEASUREMENT: SERVICE TOOLS: PROCEDURE FOR DIAGNOSTICS OF PRESSURE CIRCUITS: MEASUREMENT OF THE BASIC CIRCUIT MEASUREMENT - REAR PTO CLUTCH ENABLED MEASUREMENT - FORWARD DRIVE CLUTCH ENABLED MEASUREMENT - BACKWARD DRIVE CLUTCH ENABLED MEASUREMENT - POWERSHIFT GEAR ON - TORTOISE MEASUREMENT - POWERSHIFT GEAR ON - TORTOISE COMBINATION OF ENABLED CIRCUITS METHODS FOR DETECTION AND REMOVAL OF VALVE DEFECTS SETUP OF PRESSURE RELIEF VALVE C PRESSURE RELIEF VALVE C1 FUNCTION CHECK CHECK FOR FUNCTION OF THE V1, VM, VB, P1, P2, AND P3 VALVES CONTROL UNIT DESCRIPTION OF THE UNIT SIMPLIFIED CIRCUIT DIAGRAM CONTROL UNIT DIAGNOSTICS PIN CONNECTOR PIN CONNECTOR DESCRIPTION OF DEFECT CODES

3 1 DESCRIPTION OF DISTRIBUTOR Transmission distributor is placed on the right hand side of the transmission behind the fuel tank. The transmission distributor controls pressure oil supply to the travel clutches, torque powershift and the clutch of rear PTO. 1.1 DESCRIPTION OF INPUTS, OUTPUTS AND THREADED JOINTS FRONT SIDE Z inspection opening M14x1,5 (used for pressure measurement in the basic circuit behind the oil filter cartridge) DP inspection opening, M10 x 1 DF inspection opening M10 x 1 (used for oil pressure measurement in the travel clutch for forward drive) DM1 inspection opening M10 x 1 (used for oil pressure measurement supplied to clutch No.1 of the powershift gear) DMB inspection opening M10 x 1 (used for oil pressure measurement in beam strap circuit of the powershift gear) B DN oil output for washing and cooling of tractor rear brakes oil output for greasing of multiplier bearings PTO oil pressure output to PTO clutch OR C2 logical, ball valve (shifts according to geared Tortoise 1 or Tortoise 2) main safety pressure relief valve, 2.5 MPa 4

4 RIGHT SIDE C 1 operation, pressure relief valve, 1.7 MPa MPa CP CT oil output to transmission oil cooler return branch from transmission oil cooler VB solenoid valve for multiplier, turning Tortoise 2 on (oil pressure in MB + M 1) V 1 TS VM relief valve (it closes automatically by impulse from the alternator via the control unit after engine starts) temperature sensor (up to 50 ºC cold oil is signalled to the control unit, the travel control unit switches off after more than 110 ºC) solenoid valve for multiplier, turning Tortoise 1 on (oil pressure in M 1 + M 2) DM 2 inspection opening for oil pressure measurement to clutch No. 2 of the multiplier CC pressure relief valve of oil cooler, 0,5 MPa LEFT SIDE P P 1 P 2 P 3 PS oil pressure supply from the transmission pump proportional solenoid valve for power take-off (PTO) proportional solenoid valve for travel clutch for forward drive proportional solenoid valve for travel clutch for backward drive main pressure switch (set to 10 bar) PSR pressure switch; monitors oil pressure at output to the travel clutch for backward drive (set to 2 bar) 5

5 UNDERSIDE DPTO inspection opening, M10 x 1, for oil pressure measurement in the power take-off (PTO) clutch MB oil pressure output to beam strap of the multiplier cylinder M 1 oil pressure output to multiplier clutch No. 1 M 2 oil pressure output to multiplier clutch No. 2 PSF pressure switch; monitors oil pressure at output to the travel clutch for forward drive (set to 2 bar) Fi oil filter (oil cleaner) REAR SIDE AND UPPER SIDE 1 technological plugs DR SR T DS SF L inspection opening, M10 x 1, for oil pressure measurement in travel clutch for backward drive oil pressure output to travel clutch for backward drive oil waste from pressure circuits when solenoid valves are closed oil output for lubrication of travel clutches oil pressure output to travel clutch for forward drive waste (short-term waste from valve V1 - only when motor starts) Outputs CP, CT, B, DN and DS are located in waste branch of the clutch distributor 6

6 1.2 BASIC DISTRIBUTOR SCHEME 7

7 1.3 PRELIMINARY WORKS BEFORE MEASUREMENT Tank disassembly: Disassemble tractor cab floor. Disassemble fixing bands of the tank. Move the tank on consoles about 15 cm from the tractor body. Pad with suitable supports on the rear tank end. Disassemble rear tank console. 1.4 ELECTRIC WIRING INSPECTION Operation of the electric wiring must be inspected before measurement of hydraulic circuits Check tension of V-belt at the alternator Check damage to controls Check all contact of switches and electric wiring Check cabling of solenoid and proportional valves Check whether all connectors of electric valves are fixed properly Check after starting whether recharging light goes off and whether tachometer operates 8

8 2 DIAGNOSTICS OF HYDRAULIC CIRCUITS OF TRANSMIS- SION 2.1 BEFORE MEASUREMENT: Check oil cartridge in the transmission Check cleanliness of oil suction and pressure filter and if necessary, replace the cartridge Visually check connections in the transmission hydraulic circuit 2.2 RULES FOR MEASUREMENT: Transmission oil must be heated to about over 50 C. Measure at approximate 800 rpm idle speed. When engine revs increase, pressure in basic circuit increases because preferential lubrication of travel clutches is arranged in the waste branch using small nozzles. At 2200 rpm the pressure may increase up to 40 bar! Therefore, we use 40 bar manometer. Measurement at higher rpm may distort the result. Before and during measurement on the tractor with engine started the main gear lever and reduced speeds gear lever must be set to neutral. Before measurement, the shuttle control lever must be set to neutral, PTO clutch switch in disabled position, powershift gear set to H position (no multiplier light is lit on the dashboard). 2.3 SERVICE TOOLS: - For measurement use the diagnostic set From the diagnostic set case prepare a set for measurement of pressure in the clutch distributor. 9

9 2.4 PROCEDURE FOR DIAGNOSTICS OF PRESSURE CIRCUITS: Measure the basic circuit first. - this is used to check correct operation of the transmission pump, V1 valve, pressure relief valve C1 and general tightness of the clutch transmission. Then, measure each hydraulic circuit of the clutch transmission. - this is used to find out function and tightness of each circuit. In the third phase, combine measurements of each circuit. - this is used to check function and tightness of each circuit in combination of several circuits enabled. 10

10 2.5 MEASUREMENT OF THE BASIC CIRCUIT Oil flow scheme - NEUTRAL 1- RADIATOR P- OIL SUPPLY TO PUMP 11

11 Measurement procedure 1. Use the inspection opening Z to connect 40 bar manometer! 2. You must measure bar on the Z opening. Measure at approximate 800 rpm idle speed. 3. Conclusion of the test a) the manometer reads pressure 0 to 2 bars 1. valve V1 remains open check function of the V1 valve 2. no pressure from the transmission pump - check the transmission pump with manometer with throttle valve 3. pressure relief valve C1 remains open - dismount the pressure relief valve C1 and check for proper function b) the manometer reads pressure more than 0 bar and lower than bar 1. incorrect setup of the pressure relief valve C1 - release the lock nut and use Allen wrench to tight he bolt; if pressure on the manometer increases use the bolt to set correct pressure; secure the lock nut with paint after tightening 2. lower pressure from the transmission pump - check the transmission pump with manometer with throttle valve 3. leaking pressure relief valve C1 - dismount the pressure relief valve C1 and check for proper function 12

12 c) the manometer reads pressure higher than 17 to -19 bar 1. incorrect setup of the pressure relief valve C1 - release the lock nut and use Allen wrench to loose he bolt; if pressure on the manometer decreases use the bolt to set correct pressure; secure the lock nut with paint after tightening 2. pressure relief valve C1 still closed - oil flows through main safety pressure valve C2, dismount the pressure relief valve C1 and check for proper function When pressure remains low in hydraulic circuits also after the distributor and pump defects are removed, the problem should be sought for in relevant hydraulic circuit of the powershift gear or travel clutches or the PTO clutch and disassembly of these components is required. 13

13 MEASUREMENT OF EACH HYDRAULIC CIRCUIT OF THE TRANSMISSION DISTRIBUTOR. Connect the manometers as shown on the figure: Start up the engine Before and during measurement on the tractor with engine started the main gear lever and reduced speeds gear lever must be set to neutral. Before measurement, the shuttle control lever must be set to neutral, PTO clutch switch in disabled position, powershift gear set to H position (no multiplier light is lit on the dashboard). Measure at approximate 800 rpm idle speed. 14

14 2.6 MEASUREMENT - REAR PTO CLUTCH ENABLED Oil flow scheme 1- RADIATOR P - OIL SUPPLY TO PUMP - PASS VALVE ENABLED 15

15 Measurement procedure 1. All manometers must read 0 at the beginning of the measurement. 2. Switch REAR PTO on the right hand column of the cab. 3. After the rear PTO switch is set to on, the PTO manometer connected to the DPT point must show pressure bar; all other manometers must show 0 bar throughout the measurement. After the PTO switch is set to off, the PTO manometer must read 0 bar. 4. Conclusion of the test a) the PTO manometer reads pressure 0 bar P1 valve didn't open after the PTO switch is enabled - check cabling between the PTO switch and the P1 valve - check for proper operation of the P1 valve b) the PTO manometer reads pressure lower than 17 to 19 bar the transmission distributor is okay, oil pressure drop occurs due to leaks in the PTO hydraulic circuit c) oil pressure read by some other manometer connected in addition to the PTO manometer electric wiring failure 16

16 2.7 MEASUREMENT - FORWARD DRIVE CLUTCH ENABLED Oil flow scheme 1- RADIATOR P - OIL SUPPLY TO PUMP - PASS VALVE ENABLED 17

17 Measurement procedure 1. measurement is carried out with the engine started 2. Six manometers remain connected from previous measurement 3. All manometers must read 0 at the beginning of the measurement. 4. shuttle control lever under steering wheel must be set to FORWARD (F) 5. On the inspection point DF at revs about 800 rpm and oil temperature about 50 C there must be oil pressure rise at the manometer from 0 bar to bar. 6. Conclusion of the test a) the DF manometer reads pressure 0 bar the P2 valve did not open after switching the shuttle control lever - check cabling between the shuttle control lever and the P2 valve - check for proper operation of the P2 valve b) the DF manometer reads pressure lower than 17 to 19 bar the transmission distributor is okay, oil pressure drop occurs due to leaks in the DF hydraulic circuit c) oil pressure read by some other manometer connected in addition to the DF manometer electric wiring failure 18

18 2.8 MEASUREMENT - BACKWARD DRIVE CLUTCH ENABLED Oil flow scheme 1- RADIATOR P - OIL SUPPLY TO PUMP - PASS VALVE ENABLED 19

19 Measurement procedure 1. measurement is carried out with the engine started 2. Six manometers remain connected from previous measurement 3. All manometers must read 0 at the beginning of the measurement. 4. shuttle control lever under steering wheel must be set to BACKWARD (B) 5. On the inspection point DR at revs about 800 rpm and oil temperature about 50 C there must be oil pressure rise at the manometer from 0 bar to bar. 6. Conclusion of the test a) the DR manometer reads pressure 0 bar the P3 valve did not open after switching the shuttle control lever - check cabling between the shuttle control lever and the P3 valve - check for proper operation of the P3 valve b) the DR manometer reads pressure lower than 17 to 19 bar the transmission distributor is okay, oil pressure drop occurs due to leaks in the DF hydraulic circuit c) oil pressure read by some other manometer connected in addition to the DR manometer electric wiring failure 20

20 2.9 MEASUREMENT - POWERSHIFT GEAR ON - TORTOISE 1 Oil flow scheme 1- RADIATOR P - OIL SUPPLY TO PUMP - PASS VALVE ENABLED 21

21 Measurement procedure 1. measurement is carried out with the engine started 2. Six manometers remain connected from previous measurement 3. All manometers must read 0 at the beginning of the measurement. 4. press appropriate button on the gear lever head to select tortoise 1 (one green light with tortoise symbol is on) 5. On the inspection point M1 and M2 at revs about 800 rpm and oil temperature about 50 C there must be oil pressure rise at the manometer from 0 bar to bar. 6. Conclusion of the test a) the M1 and M2 manometers read 0 bar pressure the VM valve did not open after pressing the button - check cabling between the button and the VM valve - check for proper operation of the VM valve b) the M1 and M2 manometers read pressure lower than bar the transmission distributor is okay, oil pressure drop occurs due to leaks in the hydraulic circuit c) oil pressure read by some other manometer connected in addition to the M1 and M2 manometers electric wiring failure d) the manometer M2 reads pressure lower than bar or 0 bar logical component OR failure, did not open either partially or at all 22

22 2.10 MEASUREMENT - POWERSHIFT GEAR ON - TORTOISE 2 Oil flow scheme 1- RADIATOR P - OIL SUPPLY TO PUMP - PASS VALVE ENABLED 23

23 Measurement procedure 1. measurement is carried out with the engine started 2. Six manometers remain connected from previous measurement 3. press appropriate button on the gear lever head to select tortoise 2 (two green lights with tortoise symbol are on) 4. On the inspection point M1 and MB at revs about 800 rpm and oil temperature about 50 C there must be oil pressure rise at the manometer from 0 bar to bar. 5. Conclusion of the test a) the M1 and MB manometers read 0 bar pressure the VB valve did not open after pressing the button - check cabling between the button and the VB valve - check for proper operation of the VB valve b) the M1 and MB manometers read pressure lower than bar the transmission distributor is okay, oil pressure drop occurs due to leaks in the hydraulic circuit c) oil pressure read by some other manometer connected in addition to the M1 and MB manometers electric wiring failure d) the manometer M1 reads pressure lower than bar or 0 bar logical component OR failure, did not open either partially or at all 24

24 2.11 COMBINATION OF ENABLED CIRCUITS These tests are composed by combinations of previous measurements. They are carried out after measurement of the basic circuit, measurement of each hydraulic circuit of the transmission distributor and after removal of potential defects identified during the measurements. THESE COMBINATIONS OF ENABLED CIRCUITS ARE PERFORMED BECAUSE LEAKS OF HYDRAULIC CIRCUITS MAY NOT REVEAL DURING MEASUREMENT OF INDIVIDUAL CIRCUITS BUT THEY MAY AP- PEAR AFTER COMBINATION OF SEVERAL CIRCUITS CONNECTED TOGETHER! The following sequence of measurements needs to be complied with to ensure proper diagnosis! Rules for measurement: Transmission oil must be heated to about over 50 C. Measurement is carried out at idle speed about 800 rpm. Measurements taken at higher rpm may distort the result. Before and during measurement on the tractor with engine started the main gear lever and reduced speeds gear lever must be set to neutral. Before measurement, the shuttle control lever must be set to neutral, PTO clutch switch in disabled position, powershift gear set to H position (no multiplier light is lit on the dashboard). Description of each figure identifies the circuits being connected. Pressure read from each manometer must comply with the depiction. When connecting another hydraulic circuit the oil pressure may drop for a moment for manometers of the circuit already connected. This is not a failure and the reason is that measurement is carried out at idle engine speed, i.e. at minimum oil supply from the pump. CIRCUITS BEING CONNECTED ARE DESCRIBED IN BRIEF. FORWARD DRIVE clutch enabled powershift gear on - tortoise 1 FORWARD DRIVE clutch enabled powershift gear on - tortoise 2 25

25 FORWARD DRIVE clutch enabled PTO clutch engaged FORWARD DRIVE clutch enabled powershift gear on - tortoise 1 PTO clutch engaged FORWARD DRIVE clutch enabled powershift gear on - tortoise 2 PTO clutch engaged BACKWARD DRIVE clutch enabled powershift gear on - tortoise 1 26

26 BACKWARD DRIVE clutch enabled powershift gear on - tortoise 2 BACKWARD DRIVE clutch enabled PTO clutch engaged BACKWARD DRIVE clutch enabled powershift gear on - tortoise 1 PTO clutch engaged BACKWARD DRIVE clutch enabled powershift gear on - tortoise 2 PTO clutch engaged 27

27 2.12 METHODS FOR DETECTION AND REMOVAL OF VALVE DEFECTS 2.13 SETUP OF PRESSURE RELIEF VALVE C1 Loose the lock nut (1). Set pressure by a bolt (2). To increase pressure, tighten the bolt (2); to decrease pressure, loose the bolt. After setting, lock the bolt (2) by tightening the lock nut (1). Apply paint to the lock nut PRESSURE RELIEF VALVE C1 FUNCTION CHECK Disassemble the pressure relief valve C1. Disassemble using a box spanner on a hexagon socket (1). Supply air pressure to the valve; the valve must not leak. In case of valve leak, disassemble the valve by screwing the hexagon socket out (2). Clean the valve, re-assemble and check for proper operation by pressure air. After the valve is assembled in the distributor, make setup according to CHECK FOR FUNCTION OF THE V1, VM, VB, P1, P2, AND P3 VAL- VES It is necessary to check potential damage of wiring to solenoid valves. A tester connected to contacts of a valve is used for this purpose. There must be voltage on the valve connector after pressing on relevant switch. Check the solenoid valve as well. Disassemble valve from the distributor and keep power supply active. Press button of the valve and observe whether slide moves. If the slide does not move, the solenoid valve is defective. Check the solenoid coil of the valve. Disconnect air supply and measure at least 8 Ohm resistance on the coil contacts. Also check for damage sealing rubber rings of the slides. In case of pump failure proceed as follows: If at idle speed 800 rpm and oil temperature over about 50 C the pressure is under 17 bar, the pump is defective and it is likely worn-down. Then, try increase the revs; if no pressure increases, failure of the pressure relief valve can be assumed. Conclusion: When pressure remains low in hydraulic circuits also after the distributor and pump defects are removed, the problem should be sought for in relevant hydraulic circuit of the powershift gear, travel clutches or the PTO clutch and disassembly of these components is required. 28

28 3 CONTROL UNIT 3.1 DESCRIPTION OF THE UNIT pin SIGNAL INPUT FROM SHUTTLE CONTROL LEVER (NEUTRAL POSITION) 2- SIGNAL INPUT FROM SHUTTLE CONTROL LEVER (FORWARD POSITION) 3- SIGNAL INPUT FROM SHUTTLE CONTROL LEVER (BACKWARD POSITION) 4- SIGNAL INPUT FROM REAR PTO SWITCH AND PTO RUNNING SPEED SWITCH ON THE COLUMN 5- SIGNAL INPUT FROM REAR PTO SWITCH AND PTO RUNNING SPEED SWITCH ON THE COLUMN 6- SIGNAL INPUT FROM GEAR LEVER SWITCH (CLUTCH) 7- SIGNAL INPUT FROM SWITCH ON POWERSHIFT GEAR (H) ON THE GEAR LEVER 8- SIGNAL INPUT FROM SWITCH ON POWERSHIFT GEAR (L) ON THE GEAR LEVER 9- SIGNAL INPUT FROM POWERSHIP GEAR PRE- SELECTION SWITCH 10- SIGNAL INPUT FROM ALTERNATOR (W) 11- SIGNAL INPUT FROM TRAVEL SENSOR 12- SIGNAL INPUT FROM LOWER POSITION OF CLUTCH PEDAL SWITCH 13- OUTPUT TO TORTOISE 1 LIGHT 14- OUTPUT TO TORTOISE 2 LIGHT 15- SIGNAL OUTPUT TO RED TRACTOR LIGHT 16- SIGNAL OUTPUT TO TRANSMISSION ERROR LIGHT 17- TEST DIAGNOSTIC PIN (NOT CONNECTED) 18- SIGNAL INPUT START PROTECTION 19- SIGNAL OUTPUT START PROTECTION 20- SIGNAL INPUT (+) POSITION AND SWITCHING BO- XES 21- (-) SIGNAL OUTPUT (-) VEHICLE BODY NOT USED Fig. 1 pin (-) BODY FOR CONTROL VALVES VP1-VP3 2- SIGNAL OUTPUT FOR VALVE (VP1)PTO OF TRANSMISSION DISTRIBUTOR 3- SIGNAL OUTPUT FOR VALVE (VP2) FORWARD DRIVE OF TRANSMISSION DISTRIBUTOR 4- SIGNAL OUTPUT FOR VALVE (VP3) BACKWARD DRIVE OF TRANSMISSION DISTRIBUTOR 5- (-) VEHICLE BODY 6- SIGNAL OUTPUT FOR VALVE CONTROL (VB) OF POWERSHIFT GEAR TORTOISE 2 7- SIGNAL OUTPUT FOR VALVE CONTROL (VM) OF POWERSHIFT GEAR TORTOISE 1 8- SIGNAL OUTPUT FOR VALVE V1 9- SIGNAL INPUT FROM SENSOR (PS) - MAIN PRES- SURE SWITCH 10- SIGNAL INPUT TO TEMPERATURE SENSOR 11- SIGNAL OUTPUT FROM TEMPERATURE SENSOR 12- NOT USED 13- SIGNAL INPUT FROM SENSOR (PSR) - PRESSURE SWITCH FOR BACKWARD DRIVE 14- SIGNAL INPUT FROM SENSOR (PSF) - PRESSURE SWITCH FOR FORWARD DRIVE 15- SIGNAL OUTPUT (+) TO SENSOR OF CLUTCH PE- DAL - ATTENTION, 5V VOLTAGE 16- SIGNAL INPUT FROM SENSOR OF CLUTCH PEDAL 17- SIGNAL OUTPUT (-) TO SENSOR OF CLUTCH PE- DAL - ATTENTION, 5V VOLTAGE 18- NOT USED (A) audio signal output. If the output is covered by a label, remove it. The label attenuates audio signal for the failure signalling. It is used for audio signalling output protection during handling and assembly. 29

29 3.2 SIMPLIFIED CIRCUIT DIAGRAM Fig CONTROL UNIT DIAGNOSTICS In case of failure of any function of the control unit, measure the voltage values at each pin of relevant circuit. Use a diode tester, multimeter etc. for measurement. DO NOT USE A TESTER WITH A BULB! PIN CONNECTOR Numbering of pins, see Fig. 1. The pins are numbered on the tractor in the connector plug by the cabling. Unless explicitly SPECIFIED OTHERWISE, measurements are taken with shut-off engine, all cabling connected and ignition key switched to I position. Individual measurements and pin measurement methods 1 - signal input from shuttle control lever NEUTRAL When gearing the shuttle control lever to the NEUTRAL position you must read 12V voltage between pin 1 and 20; 0V voltage is measured when gearing the shuttle control lever to any other position. 30

30 2 - signal input from shuttle control lever FORWARD When gearing the shuttle control lever to the FORWARD position you must read 12V voltage between pin 2 and 20; 0V voltage is measured when gearing the shuttle control lever to any other position. 3 - signal input from shuttle control lever BACKWARD When gearing the shuttle control lever to the BACKWARD position you must read 12V voltage between pin 3 and 20; 0V voltage is measured when gearing the shuttle control lever to any other position. For pins 1, 2 and 3 during handling with the shuttle control lever the circuit is disconnected already when lifting the lever in the steering column axis at the beginning of moving the lever to another position. 4 - signal input from the PTO switch on the cabin column For voltage values between the pins 4 and 21, see table signal input from the PTO running-up speed switch on the cabin column For voltage values between the pins 5 and 21, see table 1. PTO SWITCH running-up SPEED SWITCH Pin No.4 Pin No.5 Disabled any position 0V 0V Enabled light running-up 0V 12V Enabled medium running-up 12V 12V Enabled heavy running-up 12V 0V Table signal input from gear lever clutch switch When the switch on the control lever is pressed, 12V voltage must be read between the pin 6 and signal input from switch on powershift gear (H) on the gear level When the switch on the control lever is pressed, 12V voltage must be read between the pin 7 and signal input from switch on powershift gear (L) on the gear level When the switch on the control lever is pressed, 12V voltage must be read between the pin 8 and signal input from powershift gear pre-selection switch After pressing the switch on the dashboard, 12V voltage must be read between the pin 9 and signal input from alternator (W) After starting up the engine, 7-9V voltage must be read between the pin 10 and signal input from travel sensor The sensor is located on the right portal in the direction of travel. When turning right hand rear wheel, alternating voltage values roughly 0.7V and 12V must be read between the pin 11 and

31 12 - signal input from lower position of clutch pedal switch When the clutch pedal is depressed, 12V voltage must be read between the pins 12 and output signal to tortoise 1 light If the powershift gear is set to (M) or (L), 12V voltage must be measured between the pin 13 and output signal to tortoise 2 light If the powershift gear is set to (L), 12V voltage must be measured between the pin 14 and signal output to red tractor light 16 - signal output to transmission error light 17 - not used 18 - signal input start protection 19 - signal output start protection If the control unit is okay, pins 18 and 19 will be connected together after switching the ignition key to position II signal input (+) position and switching boxes 21 - signal input (-) vehicle body 22 - not used PIN CONNECTOR Numbering of pins, see Fig. 1. The pins are numbered on the tractor in the connector plug by the cabling. Unless explicitly specified otherwise, measurements should be taken with engine started, gear set to neutral and braked tractor! 1 - output (-) vehicle body for pins 1, 2 and 3 - valves VP1-VP3 2 - Signal output for PTO valve control on the transmission distributor (VP1) When the PTO switch on the cab column is pressed, 12V voltage must be read between the pins 2 and 1; if the switch is off, 0V voltage must be measured. After pressing the rear PTO switch, the voltage successively increases from 0 to 12V for max time of 10 seconds depending on the running-up speed rear PTO switch. 3 - Signal output for travel clutch valve control FORWARD on the transmission distributor (VP2) When gearing the shuttle control lever to the FORWARD position you must read 12V voltage between pin 3 and 1; 0V voltage is measured when gearing the shuttle control lever to any other position. After the FORWARD running-up is switched, the voltage successively increases from 0V to 12V for about 2 seconds. 32

32 4 - Signal output for travel clutch valve control backward on the transmission distributor (VP3) When gearing the shuttle control lever to the BACKWARD position you must read 12V voltage between pin 4 and 1; 0V voltage is measured when gearing the shuttle control lever to any other position. After the BACKWARD running-up is switched, the voltage successively increases from 0V to 12V for about 2 seconds. 5 - output (-) vehicle body for pins 6, 7 and 8, 6 - Signal output for the powershift gear valve control (VB) Tortoise 2 (2 lights of the powershift gear are on) After pressing the button on the gear level (powershift gear (L)), 12V must be read between the pin 6 and Signal output for the powershift gear valve control (VM) Tortoise 1 (1 light of the powershift gear is on) After pressing the button on the gear level (powershift gear (M)), 12V must be read between the pin 7 and Signal output for V1 valve control If the tractor is not started, 0V voltage must be read between the pin 8 and 5. When the engine is started, 0V voltage must be read between the pins 8 and 5. After the tractor is started, electric impulse from the control unit closes pressure relief solenoid valve V1 and 12V voltage must be measured between the pin 8 and 5. 0V voltage must be measured if the engine is not started. 9 - signal input from sensor (PS) - main pressure switch When the engine is started, 12V voltage must be measured between the pin 9 and negative pole of electric wiring (-) signal input from temperature sensor 11 - signal output for temperature sensor pin 10 and 11 - the sensor function is measured on the distributor with the cable disconnected and not on pins 10 and 11 of the control unit! Depending on the sensor temperature, resistance according to table 2 must be measured on correctly operating temperature sensor C kohm C kohm C kohm C kohm 12 - not used 0 5, , , , , , , , , , , ,137 table Signal input from sensor (PSR) - pressure switch for backward travel clutches When setting the shuttle control lever to BACKWARD, 12V voltage must be read between the pin 13 and positive pole of electric wiring (+). When setting the shuttle control lever to FORWARD or NEUTRAL, 0V voltage must be read between the pin 13 and positive pole of electric wiring (+) Signal input from sensor (PSF) - pressure switch for forward travel clutches When setting the shuttle control lever to FORWARD, 12V voltage must be read between the pin 14 and positive pole of electric wiring (+). When setting the shuttle control lever to BACKWARD or NEUTRAL, 0V voltage must be read between the pin 14 and positive pole of electric wiring (+). 33

33 15 - signal output (+) to sensor of clutch pedal - attention, 5V voltage! Measure between pins 15 and signal input from sensor of clutch pedal Total range of the clutch pedal sensor is from 0.5V to 4.3V and the tractor uses work range of about 2 Volts (e.g. 1.6V to 3.5V); the value is approximate and it may change depending on adjustment of the clutch pedal. Measure between pins 16 and 17. When stepping on the clutch pedal the value decreases; the lowest value is signalled when the clutch pedal is fully depressed. When the pedal is released, the value increases. The highest value is signalled when the pedal is fully released. Analogue voltmeter is most suitable for measurement and the dial indicator of the voltmeter should coincide with movement of the clutch pedal signal output (-) to sensor of clutch pedal - attention, 5V voltage! Measure between pins 15 and not used 34

34 4 DESCRIPTION OF DEFECT CODES CODE DEFECT SEVERITY DEFECT DE- SCRIPTION 11 failure of the STOP The shuttle control shuttle control level indicates two level under driving and more signals of wheel the direction at the 12 Low oil pressure in the transmission STOP same time V1 main valve not closed. PS pressure switch not enabled. 13 Oil pressure STOP V1 main valve not open. PS pressure sensor remains enabled. 14 Enabling oil pressure in forward travel clutch 15 Disabling oil pressure in forward travel clutch 21 Enabling oil pressure in backward travel clutch 22 Disabling oil pressure in backward travel clutch 23 Oil temperature in transmission STOP STOP STOP STOP Defect P2 valve not open. PSF pressure sensor not enabled. P2 valve is not closed. PSF sensor remains enabled. P3 valve is not open properly. PSR sensor is not enabled. P3 valve is not closed properly. PSR sensor remains enabled. Working oil temperature in transmission exceeded Incorrect information from temperature sensor POTENTIAL REMEDY Replacement of the control level under the driving wheel. Check of cabling V1 valve inspection (replacement). PS sensor inspection (replacement). Interrupted V1 valve circuit. Interrupted PS sensor circuit. Check of cabling V1 valve inspection (replacement). PS sensor inspection (replacement). PS sensor circuit short Check of cabling P2 valve inspection (replacement). PSF sensor inspection (replacement). P2 valve circuit terminated. PSF valve circuit terminated. Check of cabling. P2 valve inspection (replacement) PSF sensor inspection (replacement) PSF sensor circuit short P3 valve inspection (replacement). PSR sensor inspection (replacement). Interrupted P3 valve circuit. PSR valve circuit terminated. Check of cabling. P3 valve inspection (replacement). PSR sensor inspection (replacement). PSR sensor circuit short. Check of cabling Reduction of tractor load or stopping of tractor. Temperature sensor check Check of cabling Notes Closed valve should be under voltage. Open valve should not be under voltage. Closed valve should be under voltage. Open valve should not be under voltage. If the tractor can drive forward, the PSF sensor or its circuit is defective. If the tractor can drive backward (the clutch remains enabled), the PSF sensor is not defective If the tractor can drive backward, the PSR sensor or its circuit is defective. If the tractor can drive (the clutch remains enabled), the PSF sensor is not defective For temperatures over 110 C 35

35 CODE DEFECT SEVERITY DEFECT DE- SCRIPTION 24 Temperature Defect Low resistance sensor overload value of the temperature sensor. 25 V1 valve circuit short 31 VM valve circuit short 32 VB valve circuit short 33 P2 valve circuit short 34 P3 valve circuit short 35 Oil temperature sensor 41 Invalid signal value for lower position of the clutch pedal 42 Unsuitable range of linear clutch sensor 43 Clutch safety switch. Defect Defect Defect Defect Defect Defect Defect Defect Defect Too low value of V1 valve resistance. V1 valve overload. Short in cabling or valve Too low value of VM valve resistance. VM valve overload. Short in cabling or valve Too low value of VB valve resistance. VB valve overload. Short in cabling or valve Too low value of P2 valve resistance. P2 valve overload. Short in cabling or valve Too low value of P3 valve resistance. P3 valve overload. Short in cabling or valve High resistance value of the temperature sensor. Invalid signal value from linear sensor in lowe position of clutch pedal Invalid range of linear clutch sensor between lower and upper position of the clutch pedal. Clutch switch not switched in correct pedal position. The switch must switch at 1.95V and more at output from the linear sensor POTENTIAL REMEDY Temperature sensor inspection (replacement). Check of cabling V1 valve inspection (replacement). Check of cabling VM valve inspection (replacement). Check of cabling VB valve inspection (replacement). Check of cabling P2 valve inspection (replacement). P2 valve circuit short Check of cabling P3 valve inspection (replacement). P3 valve circuit short Check of cabling Temperature sensor check (replacement) Temperature sensor circuit interrupted Check of cabling Recalibrate. Adjust pedal console. Adjustment of linear sensor. Linear sensor inspection (replacement). Recalibrate. Adjust pedal console. Adjustment of linear sensor. Adjust clutch pedal switch. Interrupted circuit of the clutch pedal switch. Inspection (replacement) of the clutch pedal switch. Calibrate clutch pedal Notes Tractor may not be able to be driven. Bad function of the powershift gear. May not be operational Bad function of the powershift gear. May not be operational Tractor may not be able to be driven forward. Tractor may not be able to be driven backward Depressed position signals about 1.75V. Released position signals about 3.6V. 1.95V is an approximate value depending on the power voltage PWM modulation (500Hz) 36

36 CODE DEFECT SEVERITY DEFECT DE- SCRIPTION 44 Low calibration Defect Saved calibration value of forward value is lower than travel clutch range permitted 45 High calibration value of forward travel clutch 51 Low calibration value of backward travel clutch 52 High calibration value of backward travel clutch 53 Calibration temperature Defect Defect Defect Defect Saved calibration value is higher than range permitted Saved calibration value is lower than range permitted Saved calibration value is higher than range permitted Low calibration temperature 54 Invalid calibration Defect Calibration not saved POTENTIAL REMEDY Calibrate Calibrate Calibrate Calibrate Heat oil to min. 50 C Calibrate Notes Approximate clutch calibration can be performed 37