High Voltage System Diagnosis EL-48458

Special Tools

EL-48458 Pre-Charge Tester

The EL-48458 pre-charge tester is a device designed to assist in the diagnosis of fault conditions that may be difficult to differentiate between in the drive motor generator battery and the power inverter module (PIM). The internal workings of the pre-charge tester include high voltage bulk capacitors to simulate the capacitance of the PIM. In addition, there are electronic components designed to mimic the redundant contactor pulse width modulated (PWM) command circuit in order to facilitate the closing and opening of the drive motor generator battery contactors without a PIM. The pre-charge tester also incorporates High Voltage Circuit LED indicators to alert the operator of the presence of high voltage to encourage safe operation.

The EL-48458 may be connected to the vehicle at either the PIM high voltage connection or at the drive motor generator battery high voltage terminal connection depending upon service information procedures.

Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

The High Voltage Disabling procedure will perform the following tasks:

•	Identify how to disable high voltage.

•	Identify how to test for the presence of high voltage.

•	Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

Failure to follow the procedures exactly as written may result in serious injury or death.
1. Ignition OFF, perform the High Voltage Disabling procedure for servicing at the drive motor generator control module assembly.
2. Disconnect and remove the ACCM high voltage cables from the high voltage distribution box.
3. Disconnect and remove the drive motor generator battery high voltage cables from the high voltage distribution box. Remove and retain the cable mounting block O-ring. Re-install the O-ring after testing is complete.

Important: The EL-48458 high voltage terminal cover activates an internal switch. The internal switch allows continuity of the high voltage interlock circuit (HVIC) when the cover is closed.

4. Connect the drive motor generator battery high voltage cable assembly to the EL-48458 . Ensure that the high voltage terminal cover on the EL-48458 is closed after connecting the high voltage cable assembly.
5. Place the EL-48458 contactor duty cycle switch in the Open Position.
6. Disconnect the 56-way connector from the PIM and connect the vehicle harness side connector to the EL-48458 .
7. Remove the drive motor generator control module sight shield HVIC connector from the PIM mounting block.
8. Connect the EL-48458 HVIC connector to the drive motor generator control module sight shield HVIC connector.
9. Connect the alligator clip on the EL-48458 to a 12-volt vehicle chassis ground point.
10. Install the high voltage manual disconnect lever.
11. Connect the 12-volt battery.
12. Turn the Ignition Key to RUN. The Ignition ON LED on the EL-48458 should illuminate.

⇒	If the Ignition ON LED does not illuminate, verify the alligator clip connection to ground, then remove the 56-way connector and confirm with a DMM that the 12 volt ignition circuit is supplying the proper voltage to PIM connector X1 terminal 9 when the ignition key is in RUN.

⇒	If 12 V battery voltage is measured at PIM connector X1 terminal 9 then the EL-48458 is not functioning and must be replaced.

Important: A battery charger should not be connected to the vehicle during testing. Insure the 12 V battery is fully charged and that any external charger is removed prior to vehicle testing.

13. Perform any tests and/or diagnostics as needed.

1. Move the EL-48458 High Voltage Contactor Relay switch to the Open Position.
2. The high voltage stored within the EL-48458 internal capacitors should begin to discharge. After about 20 seconds. the HI VOLTAGE CIRCUIT indicator LEDs should operate in the following manner:

2.1.	The Greater Than 60 Volts When Lit LED should turn OFF.

2.2.	The Less Than 60 Volts When Lit LED should briefly illuminate.

2.3.	The Less Than 60 Volts When Lit LED should turn OFF.

3. Turn the Ignition Key to OFF.
4. Disconnect the 56-Way connector from the EL-48458 and the alligator clip from the ground connection. Leave the high voltage terminal cover closed.
5. Disconnect the EL-48458 high voltage interlock circuit (HVIC) connector from the drive motor generator control module sight shield HVIC connector.
6. Wait 5 minutes.
7. Perform the high voltage disabling procedure. Refer to High Voltage Disabling.
8. While still wearing your personal protection equipment, open the EL-48458 high voltage terminal cover and measure the high voltage terminal connections with a DMM using the following procedure:

8.1.	Set the voltmeter to DC mode. Verify the voltmeter works by measuring the voltage of the 12-volt battery.

8.2.	Using the voltmeter, verify the voltage measures less than 3 volts across the HVDC (+) positive and HVDC (-) negative terminals.

⇒	If the test result was more than 3 volts, the EL-48458 internal capacitors are still charged. Keep the isolation gloves on and install the high voltage terminal cover. Wait 5 minutes and then remove the cover and return to the beginning of this step.

9. When voltage is no longer present, disconnect the high voltage cables from the EL-48458 and remove the tool from the vehicle.
10. Re-assemble the vehicle as instructed in the diagnostic procedure.

Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

The High Voltage Disabling procedure will perform the following tasks:

•	Identify how to disable high voltage.

•	Identify how to test for the presence of high voltage.

•	Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

Failure to follow the procedures exactly as written may result in serious injury or death.
1. Ignition OFF, perform the High Voltage Disabling procedure for servicing at the drive motor generator battery assembly or 300V DC cables.
2. Remove the 300V DC cables from the drive motor generator battery assembly.
3. Attach the EL-48458 high voltage jumper to the drive motor generator battery high voltage terminals. Ensure proper polarity connection by connecting the orange and black stripe wire to the negative terminal.
4. Install the terminal extension cover assembly with the fasteners. Tighten the fasteners finger-tight.

Important: The EL-48458 high voltage terminal cover activates an internal switch. The internal switch allows continuity of the high voltage interlock circuit (HVIC) when the cover is closed.

5. Insert the high voltage jumper connector into the EL-48458 . Ensure that the high voltage terminal cover on the EL-48458 remains closed.
6. Place the EL-48458 contactor duty cycle switch in the Open Position.
7. Remove the 56-way connector from the PIM and connect the vehicle harness side connector to the EL-48458 .
8. Remove the drive motor generator control module sight shield HVIC connector from the PIM mounting block.
9. Connect the EL-48458 HVIC connector to the drive motor generator control module sight shield HVIC connector.
10. Connect the alligator clip on the EL-48458 to a 12-volt vehicle chassis ground point.
11. Install the high voltage manual disconnect lever.
12. Connect the 12-volt battery.
13. Turn the Ignition Key to RUN. The Ignition ON LED on the EL-48458 should illuminate.

⇒	If the Ignition ON LED does not illuminate, verify the alligator clip connection to ground, then remove the 56-way connector and confirm with a DMM that the 12 volt ignition circuit is supplying the proper voltage to PIM connector X1 terminal 9 when the ignition key is in RUN.

⇒	If 12 V battery voltage is measured at PIM connector X1 terminal 9 then the EL-48458 is not functioning and must be replaced.

Important: A battery charger should not be connected to the vehicle during testing. Ensure the 12 V battery is fully charged and that any external charger is removed prior to vehicle testing.

14. Perform any tests and/or diagnostics as identified by the service information procedure.

1. Move the EL-48458 High Voltage Contactor Relay switch to the Open Position.
2. The high voltage stored within the EL-48458 internal capacitors should begin to discharge. After about 20 seconds. the HI VOLTAGE CIRCUIT indicator LEDs should operate in the following manner:

2.1.	The Greater Than 60 Volts When Lit LED should turn OFF.

2.2.	The Less Than 60 Volts When Lit LED should briefly illuminate.

2.3.	The Less Than 60 Volts When Lit LED should turn OFF.

3. Turn the Ignition Key to OFF.
4. Disconnect the 56-Way connector from the EL-48458 and the alligator clip from the ground connection. Leave the high voltage terminal cover closed.
5. Disconnect the EL-48458 high voltage interlock circuit (HVIC) connector from the drive motor generator control module sight shield HVIC connector.
6. Wait 5 minutes.
7. Perform the high voltage disabling procedure. Refer to High Voltage Disabling.
8. While still wearing your personal protection equipment, open the EL-48458 high voltage terminal cover and measure the high voltage terminal connections with a DMM using the following procedure:

8.1.	Set the voltmeter to DC mode. Verify the voltmeter works by measuring the voltage of the 12-volt battery.

8.2.	Using the voltmeter, verify the voltage measures less than 3 volts across the HVDC (+) positive and HVDC (-) negative terminals.

⇒	If the test result was more than 3 volts, the EL-48458 internal capacitors are still charged. Keep the isolation gloves on and install the high voltage terminal cover. Wait 5 minutes and then remove the cover and return to the beginning of this step.

9. When voltage is no longer present, disconnect the high voltage cables from the EL-48458 and remove the tool from the vehicle.
10. Remove the terminal extension cover and the EL-48458 high voltage jumper from the drive motor generator battery assembly.
11. Re-assemble the vehicle as instructed in the diagnostic procedure.