Circuit/System Testing
WARNING: This page is about a different car, the 2012 GMC Yukon, 2012 Chevrolet Tahoe, and 2012 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
- 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.
- Safety glasses with appropriate side shields when within 15 meters (50 feet) of the vehicle, either indoors or outdoors.
- Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors.
- Visually and functionally inspect the gloves before use.
- Wear the Insulation gloves with leather protectors at all times when working with the high voltage battery assembly, whether the system is energized or not.
- Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling .
- Connect the 12 V battery.
- Ignition ON, verify the scan tool, drive motor generator battery High Voltage Interlock Status parameter displays failed.
- If not the specified value and the manual disconnect is removed, refer to DTC P1AE2-P1AE4, P1B05, or P1B06 .
- Connect the EL-48458 HV precharge tester at the drive motor generator battery assembly. Refer to the EL-48458 HV precharge tester installation procedure located in High Voltage System Diagnosis (EL-48458) .
- Install the manual disconnect lever.
- Ignition ON, precharge the high voltage system by moving the high voltage contactor relay switch on the tester to the closed position. Verify that the Hi-voltage greater than 60 V LED illuminates and stays illuminated. Wait 3 minutes. Verify the high voltage 125 A fuse does not open and that the precharge does not fail.
- If the fuse opened or the precharge failed, test the internal battery assembly high voltage cables for a short to ground or an open/high resistance. If the circuits test normal, replace the drive motor generator battery assembly.
- Ignition OFF, disconnect the X2 and X3 drive motor generator power inverter module cables.
- Test for infinite resistance between the terminals listed below and ground;
- B+ (300 V) X2
- Ground (300 V) X3
- If less than the specified value replace the high voltage cables.
- Test for infinite resistance between the B+ (300 V) terminal X1 and the ground (300 V) terminal X2 cables.
- If less than the specified range replace the high voltage cables.
- Disconnect the air conditioning control module terminal B+ (300 V) X4 and the ground (300 V) terminal X5.
- Test for infinite resistance between the terminals listed below and ground:
- B+ (300 V) X4
- Ground (300 V) X5
- If less than the specified range, replace the air conditioning control module.
- Test for greater than 50k Ω between the B+ (300 V) terminal X4 and the ground (300 V) terminal X5.
- If less than the specified range, test the circuits for a short between them. If the circuits test normal, replace the air conditioning control module assembly.
- If all circuits test normal, replace the drive motor generator power inverter module.
WARNING:
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 includes the following steps:
Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:
Failure to follow the procedures may result in serious injury or death.
NOTE:
Install a manual disconnect lever with a verified good fuse or a new manual disconnect lever.