Function for Machine Monitor
| Functions For the Machine Monitor | |||||
|---|---|---|---|---|---|
| Connector A (12 Contacts) | |||||
| Condition That is Provided | Active Condition That is Provided | ||||
| Number of the Connector Contact | Function | Normal Condition (1) | Abnormal Condition (2) | Alert Indicator (3) | Action Alarm |
| 1 | High Beam (4) | Open | +Battery (4) | (5) | - |
| 2 | Not Being Used | Open | Ground | (2) (5) | X |
| 3 | Machine Performance Panel (MPP) | Floating | Ground | No Indicator | X (6) |
| 4 | Parking Brake | Open | Ground | (4) (5) | X |
| 5 | Ground for High Beam | Ground | Ground | No Indicator | - |
| 6 | Action Alarm | +Battery | Ground | No Indicator | - |
| 7 | +Battery | 12 volts (DC) | 12 volts (DC) | No Indicator | - |
| 8 | Lamp Test | Open | Ground | No Indicator | - |
| 9 | Engine Oil Pressure | Open | Ground | Gauge | X |
| 10 | Engine Coolant Temperature | Open | Ground | Gauge | X |
| 11 | Hydraulic Oil Temperature | Open | Ground | Gauge | X |
| 12 | Belt Tension | Open | Ground | (9) (5) | X |
| ( 1 ) | The normal condition that is listed occurs during normal machine operation. The following conditions are normal conditions: normal temperatures and normal pressures. Also, the high beam and the turn signals are not activated. The condition can be checked when the machine monitor is disconnected from the machine wiring harness and the engine is running. |
| ( 2 ) | The active condition that is listed occurs during abnormal machine operation. The following conditions are abnormal operation: high temperatures and low pressures. Also, the high beam and the turn signals are activated. |
| ( 3 ) | These numbers correspond to the identifiers in Illustration 1. |
| ( 4 ) | Also, Connector contact A5 must be grounded in order for the indicator for high beam to turn on. |
| ( 5 ) | These indicators are turned ON for the lamp test during engine cranking. |
| ( 6 ) | Only a short chirp is sounded by the action alarm. This is not a continuous sound. |
| Functions For the Machine Monitor | |||||
|---|---|---|---|---|---|
| Connector B (8 Contacts) | |||||
| Condition That is Provided | Active Condition That is Provided | ||||
| Number of the Connector Contact | Function | Normal Conditions (1) | Abnormal Condition (2) | Alert Indicator (3) | Action Alarm |
| 1 | Transmission Oil Temperature | Open | Ground | (7) (4) | X |
| 2 | Steering Filter Bypass | Open | Ground | (3) (4) | X |
| 3 | Differential Lube Pressure | Open | Ground | (8) (4) | X |
| 4 | Engine Fault | Floating | Ground | (6) (4) | - |
| 5 | Right Turn | Flasher | Flasher (5) | (10) | - |
| 6 | Turn Common | Open | Ground | No Indicator | - |
| 7 | Left Turn | Flasher | Flasher (5) | (1) | - |
| 8 | Not Being Used | - | - | - | - |
| ( 1 ) | The normal condition that is listed occurs during normal machine operation. The following conditions are normal conditions: normal temperatures and normal pressures. Also, the high beam and the turn signals are not activated. The condition can be checked when the machine monitor is disconnected from the machine harness and the engine is running. |
| ( 2 ) | The active condition that is listed occurs during abnormal machine operation. The following conditions are abnormal operation: high temperatures and low pressures. Also, the high beam and the turn signals are activated. |
| ( 3 ) | These numbers correspond to the identifiers in Illustration 1. |
| ( 4 ) | These indicators are turned ON for the lamp test during engine cranking. |
| ( 5 ) | Also, connector contact (B6) must be grounded in order for the indicators for the turn signals to turn ON. See the Topic "Right Turn Relay and Left Turn Relay" in the Systems Operation section of this manual. |
 | |
| Illustration 1 | g00566793 |
Alert Indicators (1) Left turn (2) Not being used (3) Steering filter bypass (4) Parking brake (5) High beam (6) Check engine light (7) Transmission oil temperature (8) Differential lube (9) Belt tension (10) Right turn | |
The alert indicators show the status of the inputs. The status will be open, grounded, or +Battery. For each connector contact of the machine monitor, Table 1, and Table 2 gives following information:
- Function
- Normal Condition
- Active condition
- Related alert indicator
- Action alarm (function)
A fault occurs when the operation of an alert indicator does not correspond to a known machine condition. Before you troubleshoot the machine, be sure that a fault exists. For a description of the abnormal machine conditions that cause the alert indicators to be ON, refer to the Operation and Maintenance Manual for the machine.
Perform the following procedures only if a fault is suspected.
A fault in an alert indicator is discovered when the operation of the indicator does not correspond to the known machine condition. The following instance is an example: The alert indicator for the transmission oil temperature is always ON, even after the machine has been shut down overnight.
When the following conditions are observed during normal operation of the machine monitor, the conditions could be faults in the alert indicators:
- Alert indicator is always ON. See the Topic "Alert Indicator is Always On" for information on checking this condition.
- Alert indicator is never ON. See the Topic "Alert Indicator is Never On" for information on checking this condition.
Alert Indicator is Never ON
Each alert indicator except the turn and high beam is OFF when the related signal wire is open.
When the alert indicator is never ON, the condition is probably caused by one of the following problems:
- Bulb that is burned out
- An undesired open circuit in the wiring harness
- Faulty switch
- Faulty machine monitor
Note: The indicators for the turn signals and the high beam operate differently. These alert indicators require a +battery signal and a separate ground. See the Topics "Turn/Hazard/Horn Switch", and "Right Turn Relay and Left Turn Relay" in the Systems Operation section of this manual.
STEP 1 - LAMP TEST
The alert indicators are turned ON by the lamp test relay when you crank the engine. See the Topic "Lamp Test" and perform the lamp test. All of the alert indicators except the turn and high beam should turn ON during the lamp test.
- No alert indicators turn ON. The circuitry for the lamp test is faulty. Troubleshoot the lamp test relay circuit and the +battery input. Check connector contact A7 at the machine monitor.
- All of the specified alert indicators are not ON. The likely problem is a bulb that is burned out. Install a new bulb and recheck the indicator. If the new bulb does not correct the problem, then the problem is probably within the machine monitor. Replace the machine monitor.
- All of the specified alert indicators turn ON during the lamp test. A known machine condition exists and the alert indicator for that condition should be ON. However, the indicator is NOT ON. Problems such as low engine oil pressure should cause the engine oil pressure indicator to be ON. Proceed to STEP 2.
STEP 2 - CHECK A PARTICULAR CIRCUIT.
Locate the switch which corresponds to the particular alert indicator which is never ON. If necessary, use the Electrical System Schematic to assist in locating the switch. Remove the signal wire from the switch. Touch the signal wire to the switch ground circuit. If a switch ground wire is not present, touch the signal circuit to frame ground. Turn the key start switch to the ON position.
- The alert indicator is OFF. Either the signal wire is open or the machine monitor is faulty. Proceed to STEP 3.
- The alert indicator is ON. The machine monitor and the signal wire to the switch are operating correctly. Therefore, the switch or the switch ground circuit must be faulty. The circuit will be open. Some alert indicators operate from two switches in series. Check the Electrical System Schematic for the particular alert indicator. Install a new switch and recheck for proper operation.
STEP 3 - CHECK THE SIGNAL WIRE CONTINUITY.
Turn the key start switch to the OFF position. The signal wire remains disconnected from the switch. Do not allow the wire to touch the frame or other wires.
On the Electrical System Schematic, trace the signal circuit from the switch to the machine monitor. Determine the signal contact (connector contact) of the machine wiring harness at the machine monitor.
Disconnect the machine wiring harness from the machine monitor. Check the continuity of the signal wire in the machine wiring harness. Measure the resistance of the signal wire. Make the measurement from the machine harness connector for the machine monitor to the disconnected switch wire.
- Resistance is less than 5.0 ê: The signal wire is okay. Therefore, the machine monitor is faulty. Replace the machine monitor.
- Resistance is greater than 5.0 ê: The signal wire is faulty. The signal wire is open in the machine harness. Repair the wire or replace the harness.
Alert Indicator is Always ON
Each alert indicator except the turn and high beam turns ON when the related signal wire is grounded. When the alert indicator is always ON, the condition is probably caused by one of the following problems:
- Undesired short to ground in the machine harness
- Switch that is faulty
- Machine monitor that is faulty
Note: The turn and the high beam indicators operate differently. These alert indicators require a +battery signal and a separate ground. See the Topics "Turn/Hazard/Horn Switch", and "Right Turn Relay and Left Turn Relay" in the Systems Operation section of this manual for a description of operation.
STEP 1 - CHECK A PARTICULAR CIRCUIT.
Locate the switch which corresponds to the particular alert indicator which is always ON. If necessary, use the Electrical System Schematic to assist in locating the switch. Remove the signal wire from the switch. Check the operation of the alert indicator.
- The alert indicator remains ON. Either the signal wire is open or the machine monitor is faulty. Proceed to STEP 2.
- The alert indicator is OFF. The machine monitor and the signal wire to the switch are operating correctly. Therefore, the switch or the switch ground circuit must be faulty or shorted. Some alert indicators operate from two switches in series. Check the Electrical System Schematic for the particular alert indicator. Install a new switch and recheck for proper operation.
STEP 2 - CHECK THE SIGNAL WIRE.
Turn the key start switch to the OFF position. The signal wire remains disconnected from the switch. Do not allow the wire to touch the frame or other wires.
On the Electrical System Schematic, trace the signal circuit from the switch to the machine monitor. Determine the signal contact (connector contact) of the machine wiring harness at the machine monitor.
Disconnect the machine wiring harness from the machine monitor. At the machine harness connector for the machine monitor, measure the resistance between the signal contact and the frame ground.
- Resistance is greater than 5000 ê. The signal wire is not causing the fault. Therefore, the machine monitor is faulty. Replace the machine monitor.
- Resistance is less than 5000 ê. The signal wire is faulty. The signal wire within the machine harness is shorted to ground. Repair the wire or replace the harness.
Action Alarm (Troubleshooting)
The action alarm is connected to +battery (123-WH) through the key start switch. The action alarm is connected to ground through the machine monitor 568-GN. When the key start switch is in the ON or the START position and the engine is not running, the action alarm sounds because the engine oil pressure and the differential lube oil flow are not present.
The Action Alarm Does Not Sound
STEP 1 - CHECK THE POWER UP POSITION.
Turn the key start switch to the ON position. The engine should not be running. The action alarm should now be SOUNDING.
- The action alarm is SOUNDING. The action alarm is operating properly. Troubleshoot the specific function that is having trouble. For the correct operation of the alarm and the alert indicators, see the Topic "Warning Operation" in the Systems Operation section of this module. If an alert indicator turns ON and the action alarm does not SOUND, replace the machine monitor.
- The action alarm does not SOUND. Proceed to STEP 2.
STEP 2 - CHECK FOR +BATTERY AT THE ACTION ALARM
Turn the key start switch to the ON position. At the action alarm, measure the voltage from the 123-WH terminal to frame ground. The voltage should be approximately 12 DCV.
- Voltage is correct. Proceed to STEP 3.
- Voltage is not correct. There is a fault. Troubleshoot the 123-WH circuit and the key start switch. Repair the faulty component or replace the faulty component. Retest the action alarm. Use the procedure in STEP 1.
STEP 3 - CHECK THE ALARM AND THE HARNESS.
Disconnect the harness connectors from the machine monitor. Place a jumper from frame ground to harness connector A6. The designation "A" is the 12 contact connector. Turn the key start switch to the ON position. The action alarm should SOUND.
- The action alarm SOUNDS: The machine monitor is faulty. Replace the machine monitor.
- The action alarm does NOT SOUND: The harness or the alarm is faulty. Proceed to STEP 4.
STEP 4 - CHECK FOR OPEN HARNESS
The harness connector remains disconnected from the machine monitor. Turn the key start switch to the OFF position. In the machine harness, measure the resistance of wire 568-GN from the machine monitor to the action alarm. The resistance should measure less than 5.0 ê.
- Resistance is less than 5.0 ê: The harness is not causing the fault. The action alarm is faulty. Replace the action alarm.
- Resistance is greater than 5.0 ê: Wire 568-GN is open. Repair the wire 568-GN or replace the wire 568-GN in the machine harness.
Action Alarm Sounds (Beeps)
Before you troubleshoot the machine be sure that a fault exists. For the correct operation of the action alarm, see the Topic "Warning Operation" in the Systems Operation section of this module. If an alert indicator is ON for a function that also activates the action alarm, then troubleshoot that particular function first.
STEP 1 - CHECK THE INPUTS.
Turn the key start switch to the OFF position. Disconnect the harness connectors from the machine monitor. This step will check all inputs that are related to the activation of the action alarm. See Tables1 and 2.
Start the engine. Measure the resistance from frame ground to each harness connector contact that is related to the action alarm.
Check the contacts A2, A4, A9, A10, A11, A12, B1, B2, and B3.
At this time, DO NOT check the input for the Machine Performance Panel (MPP). This input is at contact A3.
When the machine is running and operating normally, the resistance of each connector contact should measure more than 50 ê.
- Resistance is greater than 50 ê for all contacts that were checked: The inputs are operating correctly. Proceed to STEP 2.
- Resistance is less than 50 ê: The harness or the related switch is faulty. Turn the key start switch to the OFF position. Troubleshoot the circuit with the low resistance. The switch or the harness must be repaired or replaced.
STEP 2 - CHECK THE OPERATION OF THE MPP.
Turn the key start switch to the OFF position. Reconnect the machine harnesses to the machine monitor. Put the machine back into the mode of the original fault. (The alarm sounds continuously.)
Disconnect the harness connector from the machine performance panel (MPP). If the MPP is the cause the alarm should now stop sounding.
- The action alarm still SOUNDS: Wire 410-WH is shorted or the machine monitor is faulty. Check wire 410-WH for a short to ground in the machine harness. If the harness is okay, replace the machine monitor.
- The action alarm no longer SOUNDS: The machine performance panel (MPP) is faulty. Check the operation of the MPP. Refer to the service module Machine Performance Panel, SENR5273.
Action Alarm (Very Faint Sound)
Faint "Clicking" Sound. - When there is a very faint "clicking" sound, the likely cause is leakage at the harness. This problem can be solved by installing a 1000 ohm resistor across the terminals of the action alarm. The resistor should be 0.5 watts or more.
A Distinct Faint Sound - If the sound is a distinct beep but the sound is faint, then the most likely cause is a switch/sender circuit. The switch/sender could be incorrectly wired or the switch/sender could have an internal failure.
The fault must be present or active during the troubleshooting process.
STEP 1 - CHECK THE SWITCH/SENDER CIRCUITS.
The machine monitoring system uses a hydraulic oil temperature switch/sender and a coolant temperature switch/sender. The circuit for the switch/senders is the most likely cause of this fault.
Turn the key start switch to the ON position. Be sure that the fault is present. Listen for the sound of the action alarm. You should hear a distinct faint "beep". One at a time, disconnect the two switch/senders from the machine harness.
- If the fault remains, proceed to STEP 2.
- If the fault is no longer present, troubleshoot the switch/sender circuit that caused the fault to disappear. Be sure that the wiring of the switch/sender is correctly done. Repair the harness or the switch or replace the harness or the switch. After repairs are completed, check the system for the same fault.
STEP 2 - CHECK THE OTHER INPUT CIRCUITS.
Use the same procedures that are in STEP 1. Check all of the switches that are related to the sounding of the action alarm.
Check the following switches:
- Parking Brake Switch
- Neutral Switch
- Engine Oil Pressure Switch
- Belt Tension Control Relay
- Transmission Oil Temperature Switch
- Steering Filter Bypass Flow Switch
- Differential Lube Pressure Switch
- Contact A2 (Not being used)
Turn the key start switch to the ON position. Be sure that the fault is present. Listen for the distinct faint "beep" that indicates the fault. One at a time, disconnect each switch from the machine harness.
- If the fault remains, replace the machine monitor.
- If the fault is no longer present, troubleshoot the switch circuit that caused the fault to disappear. Be sure that the switches are correctly wired. Repair the harness or the switch or replace the harness or the switch. After repairs are completed, recheck the system for the same fault.
Lamp Test
The machine monitoring system performs a lamp test whenever the key start switch is in the START position (engine cranking). At this time, all of the alert indicators within the machine monitor except the high beam and the indicators for the turn signals turn ON. The lamp test allows the operator and service personnel to check the operation of the alert indicators.
Note: The lamp test has no effect on the turn and the high beam indicators. These alert indicators require a +battery signal for operation. The lamp test only provides a ground signal.
Glossary
+Battery - The term "+Battery" refers to any harness wire that is part of a circuit which is connected to the battery positive post. For the machine monitor, +battery voltage is + 12 DCV.
Abnormal - The term "abnormal" refers to a machine condition or a signal that is not normal. The presence of an abnormal condition or signal means that a problem exists. The warning operation is activated and the action alarm notifies the operator that there is a problem.
Connector Contact - A connector contact is the component of a harness connector that actually makes the electrical connection. Contacts are either pins or sockets.
Continuity - A complete electrical circuit with a resistance of five ohms or less
Fault - A fault is a failure of a component in the electrical system. For example, the following problems are called faults: Open or shorted harness, faulty switches, faulty sensors and faulty controls.
Floating - The status or state of a control input that is not connected to a positive source or ground
Hard Wired - The term "hard wired" refers to electrical connections within the harness that are permanent. These connections are soldered or crimped and the connections are not meant to be altered.
Harness - An assembly of two or more wires that are held together
Alert Indicator - An alert indicator is a light in the machine monitor which turns ON when an abnormal condition exists. The associated pictograph symbol identifies the machine system with the abnormal condition.
Alert Indicator Fault - An alert indicator fault occurs when the operation of an alert indicator does not correspond to a known machine condition.
Jumper - A jumper is a piece of wire that is used to make an electrical connection when you troubleshoot a problem with the machine.
Normal Condition - Normal condition is a term that is used to describe a switch or a relay. A switch or a relay that is not controlled by the application of force, temperature, pressure, or electricity is in a normal condition. This is usually the condition that is found when the component is installed on a machine. The condition may be different if the component is being bench tested off the machine. The electrical system schematic for the machine will show the condition of the components that are installed on the machine.
Signal Wire - The signal wire is the harness wire which connects the switch to the machine monitor.
Sounds - This word is used to describe the action alarm output. When the action alarm is operating properly, the alarm makes an intermittent noise. The noise is ON for one second. Then, the noise is OFF for one second. The noise is not a continuous sound.
System Voltage - The system voltage is the actual voltage that exists between the + battery post and frame ground. System voltage is also referred to as +battery voltage.
Trip Point - The term "trip point " refers to the setting for the switch. This is the point when the state of the switch will change. Changes in the state of the switch are caused by one of the following factors: temperature, fluid level, pressure, flow rate and position. The switch can change from a closed state to an open state or from an open state to a closed state. Refer to the Electrical System Schematic for the specifications on the switches. Refer to the Schematic for your particular machine.
Wring Out - Wring out refers to checking the continuity of a harness.
Schematic For The Machine Monitor
Note: Refer to the appropriate Schematic, "Electrical System" for your machine.