The diagnostics and events for the D7E Track Type Tractor Power Train Electric Drive System can be accessed through the Message Display or by using the Caterpillar Electronic Technician (Cat ET) service tool. Troubleshooting the system requires additional information from the Service Manual for the machine. The following list of references should be used to troubleshoot the systems of the machine:
| Related Service Manuals | |
| Title | Form Number |
| D7E Track Type Tractor Service Manual | KENR5156 |
| Implement Electronic and Hydraulic Control System | KENR5165 |
| Monitoring System | KENR8246 |
| C9 Engine Troubleshooting | RENR9312 |
| Additional References | |
| Electrical System Schematic | KENR5167 |
| Hydraulic System Schematic | KENR5161 |
| Cooling System Schematic | KENR5176 |
Electrical System Troubleshooting
 |
|
The Power Train Electric Drive System and the Accessory Power System will contain hazardous voltage levels during machine operation and for a period of time after machine shutdown. Do not remove any covers that will expose energized electrical components while the engine is operating. Do not remove any covers that will expose the energized electrical components while the components remain energized following an engine shutdown. Do not perform any type of electrical maintenance on the orange hazardous voltage conductors, the power train components or the accessory power system components while the engine is operating. Do not perform any type of electrical maintenance on the orange hazardous voltage conductors, the power train components or the accessory power system components while the components remain energized following an engine shutdown. Always perform the safe shutdown and de-energizing procedure before performing electrical service on the Power Train Electric Drive System or the Accessory Power System. Failure to follow these instructions could result in personal injury or death. |
Note: Before performing maintenance on the machine or before troubleshooting a problem in a machine electrical system, read and follow the maintenance guidelines that are outlined in the Troubleshooting, "Electrical Maintenance Guidelines" section of the manual. The guidelines cover all types of machine maintenance that can be performed when the Engine is shut down and when the Engine and the Generator must be in operation during a maintenance procedure.
As a reference, simplified electrical system connection schematics for the Machine ECM, the Generator ECM, the Motor ECM, the Power Inverter, and the Accessory Power Converter are included in the back of this manual.
The schematics illustrate the end connections for the control modules and the system component circuits. The schematics do not illustrate the machine wiring harness connectors. The schematics do not illustrate the circuits of machine electrical systems that are not associated with the power train components or the accessory power components.
When troubleshooting any part of the machine electrical system, the machine Electrical System Schematic in the Service Manual for your machine should be used along with this manual. The Electrical System Schematic will illustrate the complete circuit information for all of the machine electrical systems.
Unexpected Power Train Shutdown
Some of the electrical system conditions that will cause an ECM to activate a Diagnostic Code (CID) or an Event Code (EID) are severe enough to result in the Machine ECM immediately disabling the Power Train System. When those conditions occur, the brakes are applied and the machine will not be allowed to move.
A fault reset should be attempted in order to clear the CID or the EID that caused the problem. If the condition that caused the activation of the CID or the EID is no longer present, normal machine operation can resume. If the fault condition is still present, the CID or the EID will be activated again. The Power Train System will remain disabled.
Many of the Diagnostic Codes and Events that are activated by an ECM will automatically reset once the fault is no longer present.
Some of the Diagnostic Codes and Events that can be activated by an ECM require one of two different reset procedures to be performed in order to reset the active fault when the condition that caused the fault to be activated is no longer present.
The Message Display will alert the operator or the technician which of the following two reset procedures to perform.
The following "Key Cycle" fault reset procedure will reset most the active system Diagnostic Codes and active Events when the condition that caused the fault activation is no longer present.
- Stop the machine if not already stopped.
- With the engine operating, move the FNR switch to the NEUTRAL position.
- Cycle the parking brake by engaging the Parking Brake. Then, disengage the parking brake. Engage the parking brake again.
- Check the status of the active CID or the active EID.
- If the condition that caused the CID or the EID to activate is no longer present, the fault will reset and will not be reactivated. Resume normal machine operation.
- If the condition that caused the CID or the EID to activate is still present, the fault will be reactivated. Refer to the troubleshooting section of this manual that covers the specific Diagnostic Code or Event Code that is active. Follow the troubleshooting procedure in order to isolate the condition that is causing the problem.
Some Diagnostic Codes and Events that can be activated by an ECM require that the machine to be shut down in order to reset. The following reset procedure should be followed.
- With the engine operating, move the FNR switch to the NEUTRAL position.
- Engage the parking brake.
- Turn the key start switch to the OFF position.
- Wait a minimum of 2 minutes, then start the engine.
- Check the status of the active CID or the active EID.
- If the condition that caused the CID or the EID to activate is no longer present, the fault will reset and will not be reactivated. Resume normal machine operation.
- If the condition that caused the CID or the EID to activate is still present, the fault will be reactivated. Refer to the troubleshooting section of this manual that covers the specific Diagnostic Code or Event Code that is active. Follow the troubleshooting procedure in order to isolate the condition that is causing the problem.
During machine operation, if the Machine ECM detects certain abnormal machine or circuit conditions in the steering system or the power train system, a software driven "Limp Home Mode" will be available that will allow limited machine operation. The Limp Home Mode is only available when certain power train faults or conditions are detected.
For a listing of the conditions that will allow for activation of the Limp Home Mode and for more information, refer to the Systems Operation, "Features" section of this manual under the "Limp Home Mode" title.
Basic Troubleshooting Practice
Poor connections can often be the cause of a problem in an electrical circuit. When a problem is suspected to exist in a particular circuit, examine the machine wiring harness connectors that are used in the circuit. Verify that each of the connection points in the circuit are clean, dry and in good condition. If the connections are not in good condition, permanent electrical problems or intermittent electrical problems can result. Check that the wires are securely terminated in the pin or socket. Ensure that the pin or socket is seated correctly and locked in the connector body. Ensure that all of the connections in the suspect circuit are in good condition before other tests are performed.
When a troubleshooting procedure instructs you to “REPAIR THE HARNESS OR REPLACE THE HARNESS”, use the Electrical System Schematic in the Service Manual of the machine to investigate a circuit. Perform resistance checks between the harness connectors in a circuit in order to locate harness failures. Always check the ground circuit at the machine harness connector for the components.
For machine ground circuits, less than 5 ohms of resistance is required between the ground contacts of a connector and the frame ground. Excessive ground resistance that is greater than 5 ohms can cause an incorrect diagnosis of the system.
For ECM return circuits (ECM ground), resistance checks should be made between the circuit connections and the ECM harness connector return contact. Resistance checks that are made between the ECM return circuits and frame ground may register more than 5 ohms of resistance due to internal impedance in the ECM circuits.
A circuit resistance measurement of more than 5000 ohms will indicate an open in a conductor or an open in a connector. A circuit resistance check that measures more than 5 ohms and less than 5000 ohms could be an indication of a partially open connection point. The circuit may contain a connection that is corroded or loose.
When checking an individual circuit for a short circuit to another circuit or to a ground source (frame ground or a ground circuit), the circuit that is being checked must be disconnected from all of the other components and circuits. Disconnect the suspect circuit from the control module, the component, and any other switches or sensors.
A resistance reading of at least 5000 ohms is the suggested limit for determining if a circuit is shorted to another circuit or ground source. A resistance measurement of less than 5000 ohms can indicate that there could be a "leakage" of voltage or current between the two circuits that are being measured when in operation. In some instances, a resistance measurement of less than 5000 ohms may not always indicate a short circuit. The technician should use acquired knowledge and experience when determining if two circuits are shorted to each other or if a circuit is shorted to ground.
In order to aid in diagnostics of certain types of electrical circuits that are controlled by the ECM, an internal "pull up resistor" is internally connected Between ECM switch and sensor signal input circuits and an above normal voltage source.
During normal operation, the switch or sensor signal will hold the circuit low or at a certain signal amplitude. However, circuit conditions such as a loss of power to the component, a disconnection, or an open circuit will allow the circuit voltage to be pulled high through the ECM pull up resistor. This condition will result in an above normal voltage condition at the ECM contact. As a result, the ECM will activate an FMI 03 (voltage above normal) diagnostic code for the affected circuit.
The types of ECM input circuits that have pull up voltage present are:
- Pulse Width Modulated (PWM) sensor input circuits
- Switch to ground switch input circuits
- Active analog (voltage) input signal circuits
- Passive analog (resistance) input signal circuits
The ECM pull up resistor voltage should always be considered when troubleshooting one of the circuit types that are listed.
In order to aid in diagnostics of certain electrical circuits that are controlled by the ECM, an internal "pull down resistor" is connected between the ECM switch to battery type input circuits and an ECM ground circuit.
During normal operation, the closed switch contacts that are connected to a voltage source will hold the circuit high. When circuit conditions such as open switch contacts, a loss of power to the switch supply voltage, a disconnection in the switch circuit or an open circuit will allow the circuit to be pulled to ground potential through the ECM pull down resistor. This condition will result in below normal voltage at the ECM contact. As a result, the ECM will activate an FMI 04 (voltage below normal) diagnostic code for the affected circuit.
The ECM pull down resistor should always be considered when troubleshooting a switch to battery type of input circuit.
Machine Power Distribution (Fuses, Circuit Breakers, and Relays)
| |
| Illustration 1 | g02475593 |
|
Fuse Panel | |
| |
| Illustration 2 | g02475599 |
|
Fuse Panel fuse, circuit breaker, and relay assignments (F = Fuse, R = Relay, CB = Circuit Breaker) | |
The fuse panel on the D7E Track Type Tractor is located under the access panel on the lower right side of the cab.
| |
| Illustration 3 | g01456254 |
|
System voltage supplies to the fuse panel | |
Unswitched "+" battery system power is supplied to the fuse panel from the bus bar that is connected to the supply side contact of the Main Relay. Switched "+" battery system power is supplied to the fuse panel from the bus bar that is connected to the switched side contact of the Main Relay.
The Main Relay is located on the right-hand side of the fuse panel.
The following table shows the component assignments, the power circuits, the circuit description, and the connector color that the power circuits connect to the fuse panel.
Note: Refer to the complete Machine Electrical System Schematic for complete power circuit information for fuse panel circuits.
| Fuse Panel Component Assignments | ||||
| Component (Amps) | Power Circuit | Switched/Unswitched Power | Circuit Description | Fuse Panel Connector Color (Contact) |
| Fuse 1 (15A) | 186-RD(Red) | Unswitched | 12V 15A Converter Power | Brown (A) |
| Fuse 3 (15A) | 110-RD(Red) | Unswitched | 12V 20 Amp Converter | Yellow (D) |
| Fuse 4 (15A) | 116-BR(Brown) | Switched | Accugrade Components | Blue (D) |
| Fuse 5 (15A) | To Rear Floods Relay | Switched | Rear Flood Lamps | |
| Fuse 7 (10A) | 123-WH(White) | Switched | Accessory Power Converter and Electric Water Pump Controller | Blue (F) |
| Fuse 8 (10A) | 114-RD(Red) | Unswitched | Horns | Blue (C) |
| Fuse 9 (10A) | 102-RD(Red) | Unswitched | Accessory Power Converter HV Lamp | Yellow (E) |
| Fuse 10 (10A) | 176-OR(Orange) | Switched | Ripper / Winch Control | Blue (G) |
| Fuse 11 (10A) | 130-GN(Green) | Switched | Rear ROPS Flood Lamps Switch | Brown (E) |
| Fuse 12 (10A) | None | Switched | Spare | Brown (G) |
| Fuse 13 (10A) | 131-BR(Brown) | Switched | Ripper Flood Lamp | Brown (H) |
| Fuse 14 (15A) | 113-RD(Red) | Unswitched | Beacon and Custom Accessories | Yellow (C) |
| Fuse 15 (15A) | 133-RD(Red) | Unswitched | Front Flood Lamps Switch | Yellow (B) |
| Fuse 16 (10A) | 127-OR(Orange) | Switched | 12V Converter Switch Power | Yellow (F) |
| Fuse 17 (15A) | 134-YL(Yellow) | Switched | A Post and Side Flood Lamps | Yellow (G) |
| Fuse 18 (15A) | 150-RD(Red) | Unswitched | Engine ECM | Green (D, E) |
| Fuse 19 (15A) | 160-RD(Red) | Unswitched | Generator ECM | Green (C, F) |
| Fuse 20 (15A) | 170-RD(Red) | Unswitched | Motor ECM | Green (B, G) |
| Fuse 21 (15A) | 197-RD(Red) | Unswitched | Implement ECM | Green (A, H) |
| Fuse 22 (15A) | Internal Circuit | Unswitched | Spare | |
| Fuse 23 (10A) | None | Switched | Spare | Orange (C) |
| Fuse 25 (10A) | A537-PK(Pink) | Switched | Seat Compressor Switch | Orange (B) |
| Fuse 26 (10A) | 105-RD(Red) | Unswitched | Key Start Switch | Orange (H) |
| Fuse 27 (10A) | 145-RD(Red) | Unswitched | Message Display / Service Connector | Orange (G) |
| Fuse 28 (15A) | 195-YL(Yellow) | Switched | Parking brake Solenoid | Red (G) |
| Fuse 29 (10A) | 198-RD(Red) | Unswitched | Service Brake Switch | Orange (E) |
| Fuse 30 (15A) | 174-PK(Pink) | Switched | Custom Auxiliary Switch Connector | Red (E) |
| Fuse 31 (10A) | 184-BU(Blue) | Switched | Accugrade Components 2 | Red (F) |
| Fuse 32 (15A) | 107-RD(Red) | Unswitched | Power Inverter | Black (A) |
| Fuse 33 (10A) | 104-RD(Red) | Unswitched | Accessory Power Converter (APC) | Black (B) |
| Fuse 34 (10A) | 106-RD(Red) | Unswitched | Product Link Module | Red (B) |
| Fuse 35 (15A) | 140-RD(Red) | Unswitched | Machine ECM | Red (A, H) |
| Fuse 38 (15A) | 135-RD(Red) | Unswitched | Forward Flood Lamps | Black (H) |
| Circuit Breaker 1 (15A) | 108-BU(Blue) | Switched | Wiper Motors | Brown (F) |
| Circuit Breaker 2 (20A) | Internal Circuit | Switched | Blower Motor | |
| Circuit Breaker 3 (20A) | Internal Circuits | Switched | Condenser Fan | |
| Circuit Breaker 4 (15A) | 124-GN(Green) | Switched | HVAC Control Panel | Gray (G) |
| Circuit Breaker 5 (15A) | 119-RD(Red) | Switched | Nozzle Heater | Blue (E) |
| Circuit Breaker 6 (15A) | 115-PK(Pink) | Switched | Priming Pump | Orange (A) |
| Relay 2 | 608-GN(Green) | Switched | Rear Flood Lamps | Brown (C) |
| Relay 4 | C557-OR(Orange) | Switched | Condenser Relay | Gray (F) |
| Relay 5 | 515-GY(Grey) | Switched | Blower Fan High Speed | Gray (C) |
| Relay 6 | C568-WH(White) | Switched | Blower Fan Medium/High Speed | Gray (A) |
| Relay 7 | 610-OR(Orange) | Switched | Spare | Red (C) |
| |
| Illustration 4 | g01438166 |
|
Two cab bulkhead 70 contact connectors that pass many of the Machine ECM and Implement ECM circuits through the cab wall (1) CH-C10 Upper 70 contact connector (Implement ECM circuits) (2) CH-C2 Lower 70 contact connector (Machine ECM circuits) | |
Most of the Machine ECM circuits and the Implement ECM circuits that are for chassis mounted components pass through the lower right-hand cab wall in two 70 contact bulkhead connectors.
The lower CH-C2 bulkhead connector connects many circuits from the "CH" machine wiring harness that is outside of the cab to the "C-C1" harness connector for Machine ECM circuits inside of the cab.
The upper CH-C10 bulkhead connector connects many circuits from the "CH" machine wiring harness that is outside of the cab to the "RH-C6" harness connector for the Implement ECM circuits inside of the cab.
When troubleshooting an ECM circuit for a component that is located outside of the cab, the bulkhead connectors provide a good check point in a circuit that will help to isolate the location of the problem.
Disconnect the bulkhead connector on the outside of the cab. At the disconnected bulkhead connector, check the suspect circuit for short circuits, open circuits, or poor connections at the appropriate connector contacts. This check will help to determine whether the problem is in the chassis section or in the cab section of the circuit.
The lower bulkhead connector is used for Machine ECM circuits and the upper bulkhead connector is used for Implement ECM circuits.
The following illustrations show the connector contacts and the circuit assignments for the upper 70 contact bulkhead connector and the lower 70 contact bulkhead connector for the chassis CH machine wiring harness.
| |
| Illustration 5 | g01438886 |
|
Chassis side 70 contact bulkhead connector (same contact numbers as the ECM connectors) | |
| |
| Illustration 6 | g02475338 |
|
Lower bulkhead harness connector CH-C2 circuit assignments | |
| |
| Illustration 7 | g02476127 |
|
Upper bulkhead harness connector CH-C10 circuit assignments | |