D6T XE Electrical & Hydraulic Troubleshooting Caterpillar

Power Inverter - Test

Usage:

D6 B72

When an internal problem is suspected to be present in the Power Inverter, the operation of the power transistors and the transistor circuits should be tested. An internal problem in the Power Inverter may be indicated by any of the following conditions:

A Power Inverter Control ECM activated DTC 3430 for a phase power transistor driver circuit or feedback circuit.
A Power Inverter Control ECM activated EID for Power Inverter Transistor signal mismatch. DTCs 905, 928, 2435, 2436, 2437, 2438, 2439, 2440, 2441, 2442, 2456, 2457.
A Power Inverter Control ECM activated EID 894 or 895 for a phase power transistor driver circuit or feedback circuit.
Other Power Train conditions that can cause the Machine ECM to disable the operation of the Power Train.

Note: Some of the troubleshooting procedures may require that the cab is removed. Refer to the appropriate removal guide for instructions. When the cab is off, the machine may still be powered and tests may still be performed through ET by using the Service and Maintenance Harness (SAM) 558-2095

Automatic Power Inverter Test

Required Tools

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Illustration 1	g02615483
Components of the Communication Adapter 3 Gp (466-6258) are listed: (1) Current version of Cat Electronic Technician (CatET) Service Tool software for use with a Windows -based personal computer (2) 478-0235 Communication Adapter 3 Group (3) 457-6114 Cable As. (Data Link Cable CA3) (4) 370-4617 Cable As. (CA3 PC USB Cable)

Note: A Communication Adapter 3 and the latest version of CatET are necessary for this procedure.

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The Power Train Electric Drive 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 or the power train components while the engine is operating.
Do not perform any type of electrical maintenance on the orange hazardous voltage conductors or the power train 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.

Failure to follow these instructions could result in personal injury or death.

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In order to avoid the build up of hazardous live voltages on the exposed surfaces, all grounding wires must be properly connected at all times during engine operation.
Any disconnected grounding wires (including the grounding bond wires, the conductor shield wires, the power inverter grounding straps and the component housing grounding straps) must be properly reconnected before the engine is started.

Failure to follow these instructions could result in personal injury or death.

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Table 1
Troubleshooting Test Steps	Values	Results
1. Safe Shutdown Procedure This procedure must be performed before service is performed in an area that is in the vicinity of Power Train hazardous voltage components and conductors to ensure that the DC power bus voltage has discharged properly. Reference: Refer to the Troubleshooting, "Electrical Maintenance Guidelines" section of this manual. Perform the "Safe Shutdown Procedure for Electric Drive Tractors" before proceeding with this procedure.	The Safe Shutdown Procedure for Electric Drive Tractor has been performed. DC voltage has been discharged to less than 50.0 VDC.	OK: The Safe Shutdown Procedure for Electric Drive Tractors has been performed. The Monitoring System Display and the Hazardous Voltage Indicator indicate that DC voltage is less than 50.0 VDC. The hazardous voltage has been properly discharged. The power train system for the machine can now be serviced. NOT OK: The DC voltage is greater than 50.0 VDC on the Monitoring System Display or Hazardous Voltage Indicator. REPAIR: Wait for at least 10 minutes. Repeat the “Safe Shutdown Procedure for Electric Drive Tractors”. If the voltage is greater than 50.0 VDC, voltage is still present in the system. Measure the voltage between ground and the conductors with a multimeter. Verify that there is less than 50.0 VDC present between all exposed bus contacts before any other action is taken. NOTE: Do not make personal contact with the exposed conductors until you have manually measured for voltage between ground and the conductors. Proceed to the next test step.
2. Run the Automatic Power Inverter Test. A. Turn the key switch to the ON position. B. Connect the Communication Adapter 3. C. Open the Cat ET program and establish communication. Select the Power Inverter Control ECM. D. Once communication with the Power Inverter Control ECM has been established, select the Diagnostics tab on the top tool bar. E. From that drag down menu, select “Diagnostic Tests”. The window should now display all available Diagnostic Tests. F. Select ALL of the check boxes for “Power Inverter Test”. Selecting all the boxes will run the test for both sides of the Power Inverter. G. Satisfy the required setup test conditions shown on the test window.	Communication has been established with the Power Inverter Control ECM and the required setup conditions have been met.	OK: Communication has been established with the Power Inverter Control ECM and the required setup conditions have been met. Proceed to the next test step. NOT OK: Communication has not been established with the Machine ECM or the required setup conditions have not been met. REPAIR: Ensure that setup conditions are correct: Parking brake must be set. Engine speed must be zero. DC Power Bus Voltage must be less than 50 Volts. NOTE: Some active faults may cause Cat ET not to run. Cat ET will list the active faults. Correct these faults first, if possible, before running Cat ET
3. Begin the Power Inverter Test. A. Click the Next button to begin the test. B. After the Power Inverter Test has been started, Cat ET will perform an internal Power Inverter circuit check. Note: The Power Inverter service test will discontinue if the key switch is turned to the OFF position or to the START position, engine speed is detected, or one of the circuit voltages goes above 50V.	The Power Inverter Test has concluded with a “Service Test Successful” message.	OK: The Power Inverter Test has concluded with a “Service Test Successful” message. The service test could not identify an error with the Power Inverter or Electric Drive system at this time. NOT OK: The Power Inverter Test aborted due to one of the following error messages: 0009 – Aborted by ECM 114f – DC Power Bus Voltage Too High 1237 – Power Inverter Priming Supply Not Responding E1518 – Power Inverter Priming Supply Not Responding to command REPAIR: Correct the issue and rerun the Power Inverter Test. NOT OK: The Power Inverter Test failed with an error message. NOTE Multiple error IDs can be logged. The last error message is displayed by the pop-up window. Click the “More” button to display the full list of errors. REPAIR: Proceed to Test Step 5 and follow the troubleshooting steps to determine the cause of the problem.
4. Check for Transistor Signal Mismatch Error Codes. 0x126B Phase A Transistor #1 Signal Mismatch 0x126F Phase A Transistor #2 Signal Mismatch 0x1273 Phase B Transistor #1 Signal Mismatch 0x1276 Phase B Transistor #2 Signal Mismatch 0x127B Phase C Transistor #1 Signal Mismatch 0x127F Phase C Transistor #2 Signal Mismatch	The Power Inverter Test did not log a Transistor Signal Mismatch error code.	OK: The Power Inverter test did not log a Transistor Signal Mismatch error code. Proceed to the next test step. NOT OK: The Power Inverter Test output a Transistor Signal Mismatch error code. The Power Inverter is signaling a hardware fault. REPAIR: Replace or repair the Power Inverter. Rerun the Power Inverter service test to ensure that the problem has been corrected.
5. Check for Transistor Not Responding Error Codes. 0x126A Phase A Transistor #1 Not Responding 0x126E Phase A Transistor #2 Not Responding 0x1272 Phase B Transistor #1 Not Responding 0x1274 Phase B Transistor #2 Not Responding 0x127A Phase C Transistor #1 Not Responding 0x127C Phase C Transistor #2 Not Responding	The Power Inverter Test did not log a Transistor Not Responding error code.	OK: The Power Inverter Test did not log a Transistor Not Responding error code. Proceed to the Test Step 10. NOT OK: The Power Inverter Test output a Transistor Not Responding error code. The test is indicating there is an issue with the Control Harness between the Power Inverter and the Machine ECM. Or, there is an issue with the Power Inverter. REPAIR: Troubleshoot the Control Harness first. Proceed to Test Step 7.
6. Inspect the Control Harness. A. Turn the key switch and disconnect switch OFF. B. Ensure that the connectors have not been cross threaded and are properly installed. C. Check for brass shavings in the connector that may have been created by cross threading. The shavings can short pins together. D. Inspect and clean all the contacts of the harness connectors. Ensure that all the wires and sockets are secured in the connector. Ensure that the contacts are clean, dry, and in good condition. Ensure none of the pins at the ECM and Power Inverter are bent. The following steps will check for a short from the wire of interest to the other wires in the Control Harness. E. At the Power Inverter connector, measure the resistance between the transistor signal contact and each of the other Power Inverter contacts. F. At the Power Inverter connector, measure the resistance between the transistor feedback contact and each of the other Power Inverter contacts.	Each of the resistance measurements between the transistor signal contact and all the other contacts used in the harness is greater than 5 kΩ. Each of the resistance measurements between the transistor feedback contact and all the other contacts used in the harness is greater than 5 kΩ.	OK: The Control Harness is free of damage, dirt, corrosion, and moisture. Each of the resistance measurements is greater than 5 kΩ. The resistance measurements indicate that the transistor circuits are not shorted to another circuit in the Control Harness. Proceed to Test Step 8.d NOT OK: There is a contamination problem with the Control Harness. Or, at least one of the resistance measurements is less than 5 kΩ, indicating a short in the Control harness. REPAIR: Clean all moisture, dirt, and corrosion from the harness. If the harness is damaged, repair or replace the Control Harness. After the harness issue is fixed, repeat the Troubleshooting, “Power Inverter – Test” to ensure that the problem has been corrected.
7. Check The Circuit For An Open. The key switch and the disconnect switch remain in the OFF position. The Control Harness connectors remain disconnected from the Power Inverter and the Machine ECM. The following steps will check for continuity from one end of the Control Harness to the other. A. Check the resistance between the transistor signal at the ECM harness connector and the Power Inverter harness connector. B. Check the resistance between the transistor feedback at the ECM harness connector contact and the Power Inverter harness connector.	Each of the resistance measurements between the end contacts for the transistor signal circuit and between the end contacts for the transistor feedback circuit are less than 5.0 Ω.	OK: Each of the resistance measurements is less than 5.0 Ω. The resistance measurements are indicating that the transistor signal and feedback circuits are not open in the Control Harness. Proceed to Test Step 9. NOT OK: At least one of the resistance measurements is greater than 5.0 Ω. There is an open circuit or a poor connection in the Control Harness. REPAIR: There is an open circuit or a poor connection in the transistor signal or feedback circuits. Repair or replace the Control Harness. After the harness issue is fixed, repeat the Troubleshooting “Power Inverter-Test” to ensure that the problem has been corrected.
8. Check The Circuit For A Short To Ground. The key switch and the disconnect switch remain in the OFF position. The Control Harness connectors remain disconnected from the Power Inverter and the Machine ECM. The following steps will check for a short from the wire of interest to the ground contacts in the Control Harness. A. At the Control Harness connector for the Power Inverter, measure resistance between the transistor signal contact and all the ground contacts in the Control Harness. B. At the Control Harness connector for the Power Inverter, measure resistance between the transistor feedback contact and all the ground contacts in the Control Harness.	The resistance measurement between the transistor signal circuit and frame ground is greater than 5 KΩ. The resistance measurement between the transistor feedback circuit and frame ground is greater than 5 KΩ.	OK: Each of the resistance measurements is greater than 5 KΩ. The resistance measurements indicate that the transistor signal and feedback circuits are not shorted to frame ground. REPAIR: If a transistor not responding error code was logged by the power inverter test and there is no issue with the control harness, the issue is internal to the Power Inverter. Repair or replace the Power Inverter. NOT OK: At least one of the resistance measurements is less than 5 KΩ. There is a short in the Control Harness. REPAIR: There is a short circuit or a poor connection in the transistor signal or feedback circuits. Repair or replace the Control Harness. After the harness issue is fixed, repeat the Troubleshooting “Power Inverter-Test” to ensure that the problem has been corrected.
9. Check for Transistor Current Too High Error Codes 0x1269 Phase A Transistor #1 Current Too High 0x126D Phase A Transistor #2 Current Too High 0x1271 Phase B Transistor #1 Current Too High 0x1275 Phase B Transistor #2 Current Too High 0x1279 Phase C Transistor #1 Current Too High 0x127D Phase C Transistor #2 Current Too High	The power inverter test did not log a transistor current too high error code.	OK: The power inverter test did not log a transistor current too high error code. Proceed to Test Step 11. NOT OK: The power inverter test output a transistor current too high error code. The test is indicating there is an issue with the Power Inverter. REPAIR: Replace or repair the Power Inverter. Rerun the “Power Inverter-Test” to ensure that the problem has been corrected.
10. Check for Transistor Current Not Detected Error Codes 0x126C Phase A Current Not Detected 0x1277 Phase B Current Not Detected 0x127E Phase C Current Not Detected	The power inverter test did not log a transistor current not detected error code.	OK: The Automatic Power Inverter Test did not log a Transistor Current Not Detected error code. Proceed to Test Step 15. NOT OK: The Automatic Power Inverter Test output a Transistor Current Not Detected error code. The test is indicating there is an issue with the Current Sensor circuitry in the Control Harness between the Power Inverter and the Machine ECM. Or, there is an issue with the Current Sensors internal to the Power Inverter. REPAIR: Troubleshoot the Current Sensor circuit within the Control Harness first. Proceed to Test Step 12.
11. Inspect the Control Harness. A. Turn the key switch and disconnect switch OFF. B. Ensure that the connectors have not been cross threaded and are properly installed. C. Check for brass shavings in the connector that may have been created by cross threading. The shavings can short pins together. D. Inspect and clean all the contact of the harness connectors. Ensure that all the wires and sockets are secured in the connector. Ensure that the contacts are clean, dry, and in good condition. Ensure none of the pins at the ECM and Power Inverter are bent. The following steps will check for a short from the wire of interest to the other wires in the Control Harness. E. At the Power Inverter connector, measure the resistance between the current sensor signal contact and each of the other Power Inverter contacts. F. At the Power Inverter connector, measure the resistance between the current sensor return contact and each of the other Power Inverter contacts.	Each of the resistance measurements between the current sensor signal contact and all the other contacts used in the harness is greater than 5 kΩ. Likewise, each of the resistance measurements between the current sensor return contact and all the other contacts used in the harness is greater than 5 kΩ.	OK: The Control Harness is free of damage, dirt, corrosion, and moisture. Each of the resistance measurements is greater than 5 kΩ. The resistance measurements indicate that the current sensor circuits are not shorted to another circuit in the Control Harness. Proceed to Test Step 13. NOT OK: There is a contamination problem with the Control Harness. Or, at least one of the resistance measurements is less than 5 kΩ, indicating a short in the Control harness. REPAIR: Clean all moisture, dirt, and corrosion from the harness. If the harness is damaged, repair or replace the Control Harness. After the harness issue is fixed, repeat the Troubleshooting “Power Inverter-Test” to ensure that the problem has been corrected.
12. Check The Sensor Circuit For An Open. The key switch and the disconnect switch remain in the OFF position. The Control Harness connectors remain disconnected from the Power Inverter and the Machine ECM. The following steps will check for continuity from one end of the Control Harness to the other. A. Check the resistance between the current sensor signal at the ECM harness connector and the Power Inverter harness connector. B. Check the resistance between the current sensor return at the ECM harness connector contact and the Power Inverter harness connector.	Less than 5 Ω.	OK: Each of the resistance measurements is less than 5.0 Ω. The resistance measurements are indicating that the transistor signal and feedback circuits are not open in the Control Harness. Proceed to Test Step 14. NOT OK: At least one of the resistance measurements is greater than 5.0 Ω. There is an open circuit or a poor connection in the Control Harness. REPAIR: There is an open circuit or a poor connection in the transistor signal or feedback circuits. Repair or replace the Control Harness. After the harness issue is fixed, repeat the Troubleshooting “Power Inverter-Test” to ensure that the problem has been corrected.
13. Check The Sensor Circuit For A Short To Ground. The key switch and the disconnect switch remain in the OFF position. The Control Harness connectors remain disconnected from the Power Inverter and the Machine ECM. The following steps will check for a short from the wire of interest to the ground contacts in the Control Harness. A. At the Control Harness connector for the Power Inverter, measure resistance between the current sensor SIGNAL contact and all the ground contacts in the Control Harness. B. At the Control Harness connector for the Power Inverter, measure resistance between the current sensor RETURN contact and all the ground contacts in the Control Harness.	The resistance measurement between the current sensor SIGNAL and frame ground is greater than 5 KΩ. The resistance measurement between the current sensor RETURN and frame ground is greater than 5 KΩ.	OK: Each of the resistance measurements is greater than 5 KΩ. The resistance measurements indicate that the current sensor signal and return circuits are not shorted to frame ground. REPAIR: If a Transistor Current Not Detected Error Code was logged by the Power Inverter test and there is no issue with the Control Harness, the issue is internal to the Power Inverter. Replace or repair the Power Inverter. Rerun the Power Inverter service test to ensure that the problem has been corrected. NOT OK: At least one of the resistance measurements is less than 5 KΩ. There is a short in the Control Harness. REPAIR: There is a short circuit or a poor connection in the current sensor signal or return circuits. Repair or replace the Control Harness. After the harness issue is fixed, repeat the Troubleshooting “Power Inverter-Test” to ensure that the problem has been corrected.
14. Check for Continuity Fault Error Codes. 0x1268 Phase A Continuity Fault 0x1270 Phase B Continuity Fault 0x1278 Phase C Continuity Fault	Tests did not log a continuity fault error code.	OK:The power inverter test did not log a Continuity Fault error code. Proceed to Test Step 18. NOT OK: If the Automatic Power Inverter test logged the Continuity Fault, the indication is that there is an open in the phase, in either the phase cable, Generator, or Power Inverter. Proceed to Test Step 16 to determine which component is causing the fault.
15. Manually Check The Phase for Continuity. Ensure that the Safe Shutdown Procedure has been completed (Step 1). Note: Do not make personal contact with the exposed conductors until you have manually measured for voltage between ground and the conductors. A. Remove the cover plates at the Power Inverter, exposing the phase lugs. B. With the phase lugs still connected to the Power Inverter, use a multimeter to check for continuity between the phase cables for the suspect phase on the Generator.	The Cat ET service test indicates that the Phase is not continuous.	NOT OK: The Cat ET service test indicates that the phase is not continuous, but when measured manually, the phase cables for a single phase test continuous. This condition indicates an issue with the Power Inverter. REPAIR: Replace the protective covers and repeat this test to verify that the inverter sees no continuity while manual measurement does show continuity. If verified, replace or repair the inverter. NOT OK: The Cat ET service test indicates that the phase is not continuous, and when measured manually, the phase cables for a single phase test is not continuous. This condition indicates an issue with the phase cable or the Electric Drive component. Proceed to Test Step 17.
16. Manually Check the Electric Drive Component for Continuity. A. Remove cab. B. Remove the phase cables from the Electric Drive component that logged the Continuity Fault. Use a multimeter to check for continuity between the A1/A2, B1/B2, and C1/C2 lugs for the phase at the Electric Drive component.	The Cat ET service test indicates that the phase is not continuous.	NOT OK: The Cat ET service test indicates that the Phase is not continuous, and when measured manually at the Electric Drive component, the A1 or A2 lugs for a single phase test continuous. This condition indicates an issue with the phase cable. REPAIR: Ensure that the phase cables are installed correctly on the Generator and Power Inverter lugs. Check continuity across the individual phase cables to determine whether the A1 or A2 phase cable is faulty. Replace the phase cables. Replace cab. NOT OK: The Cat ET service test indicates that the phase is not continuous, and when measured manually at the Electric Drive component, the A1 and A2 lugs are not continuous. This condition indicates an issue with the Electric Drive component. REPAIR: Replace the Generator.
17. Check for Isolation Error Codes. 1233 Phase A-B Isolation Error 1233 Phase A-C Isolation Error 1233 Phase B-C Isolation Error	The Automatic Power Inverter Test did not log an Isolation error code.	OK: The Automatic Power Inverter Test did not log an Isolation error code. Review the list of error outputs from the Power Inverter test. If necessary, rerun the test. NOT OK: The Automatic Power Inverter Test output an Isolation error code. The test is indicating there is a short in either the phase cable, Generator, or Power Inverter. The short could be phase to ground or phase to phase. Proceed to Test Step 19.
18. Manually Check The Phase for Isolation. Ensure that the Safe Shutdown Procedure and Starter Disable steps have been completed (Step 1 and 2). Note: Do not make personal contact with the exposed conductors until you have manually measured for voltage between ground and the conductors A. Remove the cover plates at the Power Inverter, exposing the phase lugs. B. With the phase lugs still connected to the Power Inverter, use a multimeter to check for continuity for the following 8 combinations: Phase A1 – B1 Phase A2 – B2 Phase A1 – B2 Phase A2 – B1 Phase A1 – Ground Phase A2 – Ground Phase B1 – Ground Phase B2 – Ground Note:The above example is for a Phase A-B Isolation error. Adjust the phase measurements accordingly based on the actual Isolation Error.	The Cat ET service test indicates that the phase is not isolated against either another phase or ground.	NOT OK: The Cat ET service test indicates that the phase is not isolated, but when measured manually, all 8 measurements are isolated (not continuous). This condition indicates an issue with the Power Inverter. REPAIR: Replace power inverter covers and rerun Cat ET service test, to verify that there is an isolation Fault. Also, ensure that the manual measurements indicate isolation. If verified, repair or replace the Power Inverter. NOT OK: The Cat ET service test indicates that the Phase is not isolated, and when measured manually, one or more of the measurements is not isolated (has continuity). This condition indicates an issue with the phase cable or Electric Drive component. Proceed to Test Step 19 to determine which component is faulty.
19. Manually Check the Electric Drive Component for Isolation. A. Remove the cab. B. Remove the phase cables from the Electric Drive component that logged the Isolation Fault. C. Use a multimeter to check for continuity for the following 8 combinations at the lugs: Phase A1 – B1 Phase A2 – B2 Phase A1 – B2 Phase A2 – B1 Phase A1 – Ground Phase A2 – Ground Phase B1 – Ground Phase B2 – Ground Note:The above example is for a Phase A-B Isolation error. Adjust the phase measurements accordingly based on the actual Isolation Error.	The Cat ET service test indicates that the Phase is not isolated. Measuring isolation manually will determine which component is at fault.	NOT OK: The Cat ET service test indicates that the Phase is not isolated, and when measured manually at the Generator, the phase lugs for a single phase test are isolated. This condition indicates an issue with the phase cable. REPAIR: Ensure that the phase cables are installed correctly on the Generator and Power Inverter lugs. Check continuity across the individual phase cables to determine which phase cable is faulty. If the phase cable is faulty, replace the phase cable. NOT OK: The Cat ET service test indicates that the Phase is not isolated, and when measured manually at the Generator, the lugs for a single phase are not isolated. This condition indicates an issue with the Generator. REPAIR: Replace the Generator.