Checking the Power and Ground Lines

WARNING: This page is about a different variant/trim than selected.

■ Check the Auxiliary Battery Temperature Sensor:

Ignition OFF.
Wait for 5(five) minutes after main switch OFF.
Connect voltmeter between signal and ground terminal at the temperature sensor on the BMS ECU side.
Main Switch ON.
Ignition ON (SSB LED "BLUE")
With a Voltmeter at the plugged in BMS ECU Connector, check voltage between signal and ground terminals of the Auxiliary Battery Temperature Sensor.
Specification:

About 0.3 ~ 4.9V (If Auxiliary Battery Temperature Sensor temperature is 84°F, should be about 2.2V)
WARNING:
* Warning & Notice
Hybrid Battery system uses around 270V voltage.
It may cause death or damage due to electrical shock, if you do not follow below Instructions.
- Follows instructions of workshop handbook.
- Wear and use insulated gloves and tools.
- IG "OFF", Disconnect ground cable of auxiliary battery and "OFF" the safety connector of the high voltage battery.
- Check high voltage terminal on Power Relay Assembly is lower than 30V.
- Be careful that it should not be short between terminals when measuring battery cell voltage. You may be injured due to spark, parts damage or electrical shock.
- Metallic material cause high voltage short that may cause damage of life or vehicle. Therefore, get rid of all the metallic material before working. (Metallic Material: Watch, Ring, any metallic products etc.).
- After disconnect W/H goes to BMS ECU from High voltage battery, be careful not to happen short between exposed terminal and terminal on high voltage connector.
Fig 1: BMS ECU - Circuit Diagram (1 Of 3)
Courtesy of HYUNDAI MOTOR AMERICA

Fig 2: BMS ECU - Circuit Diagram (2 Of 3)
Courtesy of HYUNDAI MOTOR AMERICA

Fig 3: BMS ECU - Circuit Diagram (3 Of 3)
Courtesy of HYUNDAI MOTOR AMERICA

Fig 4: BMS ECU Connector End View (1 Of 2)
Courtesy of HYUNDAI MOTOR AMERICA

Fig 5: BMS ECU Connector End View (2 Of 2)
Courtesy of HYUNDAI MOTOR AMERICA
Is the measured value within specification?
YES
- Perform "Inspection of Auxiliary Battery Temperature Sensor ".
NO
- Check open in each cell harness goes to BMS ECU from high voltage battery, then, if there is any faulty, repair or replace if necessary. Go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- After checking BMS ECU body case grounding, grounding1, grounding2 and grounding3, If the problem is found. Repair or replace as necessary, And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- After checking BMS ECU body case grounding, grounding1, grounding2 and grounding3, If the problems is not found. Replace the normal BMS ECU and check its state. If it is the normal state. Replace the BMS ECU, and then go to "VERIFICATION OF VEHICLE REPAIR " Procedure.

■ Inspection of Auxiliary Battery Temperature Sensor:

Ignition OFF.
Cool down the high voltage battery for more than 1 hour.
Connect GDS.
Ignition ON (SSB LED "BLUE"), select "Current Data".
With engine running or in "Ready" mode, check the "Auxiliary Battery Temperature Sensor" value.
Specification: Between -30°C (-22°F) and 55°C (131°F)

Fig 6: Screen Display - SOC 44.5% Of High Voltage Battery
Courtesy of HYUNDAI MOTOR AMERICA
Is the measured voltage within specification?
YES
- If the DTC "P1B71 High Voltage Battery Voltage too High" is detected as history, repair or replace as necessary. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- If the DTC "P0A72 Hybrid Battery Pack Over Temperature" is detected as history, repair or replace as necessary. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- If the DTC "P1BA1 High Voltage Battery FAN Fault" is detected as history, repair or replace as necessary. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- If the DTC "P1B96 High Voltage Battery Voltage Sensor Circuit Fault" is detected as history, repair or replace as necessary. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure
NO
- Go to "COMPONENT INSPECTION " procedure.