Circuit/System Testing

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

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:

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.

Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:

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.

Failure to follow the procedures may result in serious injury or death.

WARNING:

The eAssist battery pack assembly will utilize an exchange program. Please consult the most recent revision of bulletin/PI# PIC5520, available in Service Information (SI), for a list of approved eAssist battery pack assembly service procedures. Components that may be removed and serviced without exchanging the complete battery pack assembly are identified in the bulletin/PI. Please contact the GM Technical Assistance Center (1-877-446-8227) if you have any questions.

NOTE:

Each device may need to be disconnected to isolate a circuit fault. Use the Wiring Schematics and connector end views to identify the dedicated serial data circuit terminals of each device in this dedicated bus.

Perform the High Voltage Disabling procedure before proceeding with this diagnostic. Refer to High Voltage Disabling .
Reconnect the 12 V battery.
Ignition/Vehicle OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. Disconnect the harness connectors with the dedicated serial data circuits at both non communicating K112 Hybrid/EV Battery Interface Control Modules closest to the K114B Hybrid/EV Powertrain Control Module 2. It may take up to 10 min for all vehicle systems to power down.
Ignition ON/Vehicle In Service Mode. The following tests are between the disconnected devices.
Test for less than 1 V between each serial data circuit and ground.
- If 1 V or greater
  Repair the short to voltage in the circuit.
- Go to next step: If less than 1 V
Ignition/Vehicle OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. It may take up to 10 min for all vehicle systems to power down.
Test for infinite resistance between each serial data circuit and ground.
- If less than infinite resistance
  Repair the short to ground in the circuit.
- Go to next step: If infinite resistance
Test for infinite resistance between each pair or the serial data circuits.
- If less than infinite resistance
  Repair the short together in the circuits.
- Go to next step: If infinite resistance
Test for less than 2 Ω in each of the serial data circuit end to end.
- If 2 Ω or greater
  Repair the open/high resistance in the circuit.
- Go to next step: If less than 2 Ω
Replace the appropriate non communicating K112 Hybrid/EV Battery Interface Control Module.
Verify that DTC U179C is not set.
- If the DTC is set
  Replace the other non communicating K112 Hybrid/EV Battery Interface Control Module.
- Go to next step: If the DTC is not set
All OK