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Charge Portlink

Last updated: October 10, 2024

Overviewlink

The charge port assembly is made up of 4 components:

  • Charge port door
  • High voltage busbars with Ancillary Bay connector
  • Trim piece with PCB and LED indicators (located behind the door)
  • Charge port Electronic Control Unit (ECU)
  • Charge port inlet and latch

The charge port is located next to the left-hand tail light, which hides the charge inlet when the charge port door is closed. The inlet consists of two parts:

  • Inlet “puck” (charge port core)
  • Carrier
1. Charge port heater
Charge Port Puck

Different charge port interfaces are implemented as different pucks:

-Tesla North America - Guobiao - IEC CCS Combo 2

The charge port door is motorized and opens vertically. The charge port ECU is located in a separate enclosure from the charge port inlet. The charge port ECU has vehicle communication with external charge equipment such as Supercharger, Wall Connector and UMC; as well as, additional pinouts for inlet heating and High Voltage (HV) back cover sensing that previous models do not have. The charge port ECU is connected to the High Voltage System (HVS) controller area network (CAN) bus. This means it can communicate with Battery Management System (BMS), Power Conversion System (PCS), and High Voltage Processor (HVP). The High Voltage (HV) charge port busbars connect to the Ancillary Bay where power is distributed to the PCS for alternating current (AC) charging (single-phase Tesla charge port) and to the fast charge contactors at the rear of the HV battery for direct current (DC) charging. Three-phase charge ports have an additional harness that connects the AC charging portion of the charge port to a separate lever assisted Ancillary Bay connector that routes AC power directly to the PCS. The HV busbars connect to the charge port inlet and the Ancillary Bay using bolted connections, and the inlet pins are temperature monitored. The charge handle should be 5 - 10 inches (15 - 25 cm) from the charge port door for effective operation of the remote open button. The charge port inlet around the inlet pins can be heated.

Charge Port Assemblylink
1. Ancillary Bay connector
2. HV busbars
3. Charge port ECU
4. Inlet carrier with puck and latch
5. Charge port door
Charge Port Assembly, Overview Front
1. Manual release cable
2. Inlet carrier with puck and latch
3. HV busbars
4. Ancillary Bay connector
Charge Port Assembly, Overview Rear

On single-phase charge ports, the charge port HV busbars are used for AC charging (up to 48A or 32A limited by PCS). On three-phase charge ports, the busbars are only used for DC charging while a separate AC harness connects the AC charging pins to a separate AC charging Ancillary Bay connector that directly routes power to the PCS. The Ancillary Bay connector has a charge port high voltage interlock loop (HVIL or CPIL) to make sure that the HV harness connects properly to the Ancillary Bay while charging. The CPIL does not prevent driving nor HV battery power switch closing if in the open position. Inside the connector, the busbars are mounted to the Ancillary Bay using bolted connections. The bolts can be accessed through a lid on top of the connector. In order to make sure high voltage cannot be exposed, an open lid causes the CPIL circuit to remain open. Therefore, the lid needs to be sensed closed in order to allow the vehicle to charge. The busbars are held in place by their connectors at both ends and are not separately mounted to the vehicle chassis. The charge port ECU mounts to the wheel arch area with two plastic hooks and a nut.
1. HV busbars
2. Door motor (including gears)
3. Charge port door plastic trim
4. Trim PCB with UHF antenna and inductive sensor
5. Exact coil location for inductive door position detection
6. Latch assembly
7. LED-lit Tesla logo (for charge status indication)
8. Inlet carrier
Charge Port (Cosmetic Trim Piece (Black) Hidden)

The LEDs illuminate a Tesla logo on the upper left side of the cosmetic trim piece.

The flash speed pattern is inversely related to the State Of Charge (SOC). When the SOC is closer to 100% SOC, the flashing is slower, and when the vehicle is done charging, the charge port displays constant green. The flash speed is not related to the line current value or the charge limit setting.

The charge port LED is active when the charge port door is open and one of the following scenarios is true:

  • When the vehicle is locked and charging, the green LED stops flashing 2 minutes after vehicle lockout.
  • When the vehicle is unlocked and charging, the LED is illuminated during the entire charging session.
  • Once the vehicle is fully charged, the charge port LED switches to solid green.

If there is no pilot signal, the LEDs turn off (for example, unplugging a UMC from the wall while connected to vehicle). Each LED color represents a separate condition that must be met as described in the table below:

LED Color Charge Port State Set Conditions
Solid White Charging cable can be removed or inserted The charge port latch is disengaged.
Solid Amber Cable is inserted, but not properly latched The cable is connected, charge port latch is not engaged, vehicle is trying to engage latch, and vehicle is not charging.
Solid Red Either the charger, charge port, or Electric Vehicle Supply Equipment (EVSE) is not operating as expected One of the following:
  • Contactors are welded.
  • BMS error
  • Pilot error
  • Charger error
Flashing Green Charging at expected current Cable is connected, charge port latch is engaged, and vehicle is actively charging.
Flashing Amber Charging at reduced current Cable is connected, charge port latch is disengaged, and vehicle is actively charging.
Solid Green Charging is complete Cable is connected and vehicle is no longer charging.
Solid Blue Pilot is present Cable is connected and either a pilot signal or fast charger is present.

The Trim PCB holds the Ultra High Frequency (UHF) antenna used to detect Radio Frequency (RF) signals from Tesla charge handles and detects the charge port door position. There is an inductive sensor coil on the PCB, as well as a transceiver chip for the inductive sensor coil. The rear of the charge port door has a non-magnetic metallic piece that is sensed by the coil when the door is closed. The charge port ECU relies on relative changes to the inductive door sensor reading to determine that the user pushes the door to open it.

1. Charge port door (rear)
2. Metal piece
Charge Port Door (Rear)

Two low voltage (LV) harnesses connect the charge port ECU to the charge port:

  • One connects to the inner puck for proximity, pilot, inlet heating, back cover sensing and temperature measurements
  • One connects to the latch.

A third harness exists for Guobiao charge ports. On Tesla North America and IEC CCS Combo 2 charge ports, it is not used and therefore tied back.

Model Y re-introduces a back cover that needs to be removed in order to access the bolts that connect the HV busbars to the charge port inlet. If the back cover is removed, a circuit different from the CPIL is interrupted that signals this condition to the charge port ECU.
1. LV inner puck connector (proximity, pilot, inlet heating, back cover sensing, temperature measuring)
2. HV back cover
3. Latch actuator
4. Manual release arm
5. Manual latch release handle
6. Manual latch release cable guide
Charge Port Rear, Without Back Cover
1. 3 pin latch connector
2. HV busbars with orange sleeve
3. Carrier with charge port puck and latch
4. HV chargeport fasteners
5. Insulation layer between HV busbar core and outer isolation tube
Charge Port Rear, With Back Cover

Charge Port ECUlink

The charge port ECU controls the following sub-components:

  • Charge port door motor
  • Charge port door potentiometer
  • Charge port latch
  • LEDs
  • UHF antenna
  • Inductive door sensor
  • Inlet thermistors
  • Charge port heater
  • Back cover sensor

The charge port ECU connects to external charge equipment through pilot and proximity pins in the charge inlet. The charge port ECU is not connected to high voltage power. The charge port ECU enclosure is similar across multiple regions, and can house different internal hardware, resulting in different connector pinout. Therefore, in some cases it may be necessary to verify that the charge port ECU unit matches the vehicle it is being installed in.
1. 24 pin male connector for inlet LV harness (proximity, pilot, thermistors, latch drive, latch sense, inlet heater, back cover sensing)
2. 16 pin male connector for trim LV harness (LEDs, UHF, door sense,
door drive)
3. X096 vehicle interface connector (CAN, power, latch enable signal,
HVP fault signal)
Charge port ECU

A 5V source connected to a 330 Ohm resistor supplies the proximity pin. This allows detecting the presence of a charge handle, and the button press state on the handle. For IEC Type 2 and Guobiao charge handles the proximity pin is also used for identifying cable current, so the charge port knows the current rating of the connected cable and can adjust max charge rate accordingly. The charge port does not generate a digital proximity signal to the drive inverter. Instead, in the unlikely event that the cable state is unknown to the front vehicle controller (VCFRONT) and drive inverter (for instance because the charge port ECU is missing on CAN), the customer can manually override and confirm on the touchscreen that there is indeed no charge cable connected before the vehicle allows them to shift into drive.

The pilot pin detects the duty cycle of a 1 kHz PWM signal sent from external charge equipment. The duty cycle indicates the max allowable current draw from the charging station. The positive amplitude of the pilot signal indicates vehicle readiness for charging (see Gen 2 UMC Theory of Operation for more details). Additionally, the charge port ECU controls single wire controller area network (SWCAN) communication, which means the charge port ECU has the SWCAN relay and transceiver to communicate with external charging products, such as Supercharger. The charge port sends relevant CAN messages from the SWCAN bus to the HVS bus where the BMS, PCS, and HVP are connected.

The charge port ECU connects to the HVP with two hardware lines:

  • The charge port fault line
    • Bidirectional active-low signal used by HVP to disallow charging and door opening.
    • It is used to prevent HV exposure when, for instance, the fast-charge contactors are welded or assumed welded.
    • The signal can also be set low by the charge port when there are risks of HV exposure.
    • The fault line immediately stops charging (via hardware and software) if charging is active.
  • The charge port latch enable line
    • Unidirectional active high signal used by HVP to allow the charge port to drive the latch into disengaged state for cable insertion.
    • The charge port cannot drive the latch in either direction if this signal is not active.

Since there is thermal sensing of the charge port inlet power pins, the charge port ECU can read temperatures while charging which allows the vehicle to monitor temperature changes and reduce the charge rate if needed.

Note

Always consult the circuit diagram and connector reference for the vehicle being diagnosed to confirm which connector is used.

Charge Port Doorlink

The charge port door can open three different ways:

  • A request by the user interface (UI)
  • Pressing the charge port door
  • Pressing the button on a Tesla charge handle

When the charge handle is pressed, a RF signal is sent to the charge port trim PCB UHF antenna. A potentiometer mounted to the door driveshaft senses the door position. The charge port ECU uses the inductive door sensor to determine closed/open/press states. Since the inductive door position sensor is located on the lower right of the charge port door, it is easiest for the inductive sensor to detect door press when pushing at this location. The charge port ECU measures the door motor current for accurate control during door actuation, and stall current detection when reaching fully closed/open positions.

The door motor uses a gear to produce appropriate torque for door actuation. The clutch holds the door in position when it is open without need to drive the motor. This gives it a sturdy feel and makes it somewhat hard to move manually. Normally, customers should not need to manually move the door since it will automatically close 6 seconds after removing a charge handle. If customer moves the door manually when a handle is not connected, the charge port door will close.

Charge Port Inlet Latchlink

The charge port latch locks the charge handle in place when charging and current is flowing to prevent live disconnect. The charge port latch is actuated by a cam for converting rotational movement into linear movement. The picture on the left shows the latch arm mounted to the cam (without the latch cover), and the picture on the right shows just the cam with the latch arm hidden.
1. Latch seal
2. Latch arm
3. Latch cam
Charge Port Inlet With Latch

The latch uses binary position sensing to report engaged or disengaged. There is no continuous position sensing, which means there is no need for calibration either. The latch needs to be driven by the charge port ECU into engaged and disengaged positions, i.e. there is no spring to force it into engaged state if latch is undriven. The charge port drives the latch at low voltage in the engaged direction every 2 seconds whenever the vehicle is not in Drive and the latch enable hard line is asserted. This is done to confirm that the latch is connected by sensing the latch motor current, since a disconnected latch looks electrically identical to an engaged latch. This can cause a quiet “ticking” noise that is noticeable when listening closely.

Charge Port Latch Manual Release Cablelink

The charge port latch manual release cable is used in emergency situations where the latch or 12V support is not operating as expected while a charge cable is plugged in. This is the only situation the latch release cable should be used. The latch release cable should never be used to disengage the latch to force insert a charge cable. This is because if the latch does not disengage the inlet could be live. The latch release handle is accessible by users from the left-hand trunk area.
1. Latch actuator
2. Grounding busbar
3. Trunk manual latch release handle
4. LV inlet connector
5. Manual latch release cable guide
Release Cable In Trunk

Serviceabilitylink

Electrical Connectionslink

To ensure low resistance connections, all busbar connections need to be established with sufficient amount of electrical joint compound applied. Hioki resistance measurements are recommended to ensure that the resistance specifications for the joints are met.

Note

Always refer to the Service Manual for the latest instructions.
1. CPIL switch (opens when lid is removed)
2. Spring-loaded connector lid (opened)
3. HV busbar
4. Ancillary Bay header
5. Ancillary Bay connector housing
6. Connection bolts
Charge Port Ancillary Bay HV Connector

Calibrationslink

The latch does not need calibration. The door potentiometer, the inductive door closed sensor, and motor stall current measurements should allow the charge port to operate without need of door calibration.

Diagnosis Methodslink

If the charge port does not operate as expected, it is important to determine if another condition prevents the charge port from operating.

For example, the two hardware signals from HVP can prevent the latch from being driven, or the door from opening, for instance in case a fast charge (FC) contactor has welded or is assumed welded. The FC contactor can be assumed welded if the FC contactor logic harness in the HVC is disconnected or damaged. In this case, alerts from HVP will be present, so generally it is a good idea to resolve all HVP alerts prior to resolving charge port issues.

Additionally, as shown in the charge port LED state table, whenever the BMS is in a faulted state the charge port LED will show red LEDs, so any BMS alerts should be diagnosed before suspecting issues with charge port.

The latch does not have a position sensor, only a closed/open binary state signal.

The door potentiometer gives a position value for the door which can be used for diagnosing charge port door issues.

If the inductive door position sensor is not operating as expected the door may not open when pressing the door, or it may open when not pressing the door. In the former case, the door could be opened by using charge handle or UI. The door will never open when the vehicle is in Drive.

  • If the vehicle is in Drive gear, the door will not open using the UI, charge handle button, or press-to-open.
  • If the drive rail is enabled but the vehicle is in Park, and either a UI or charge handle open request is received, the front vehicle controller (VCFRONT) will attempt to disable the drive rail. The drive rail will not be disabled with a push-to-open request.

If the latch fails to engage, the vehicle will not allow DC charging, but will be able to AC charge at up to 16A. This is usually sufficient for emergency charging so that the vehicle can drive to a Service Center. If a handle does not latch when inserted in the charge port, inspect the charge port inlet and handle for any signs of obstruction, try a different handle, or very gently wiggle the handle.

Partslink

These are the only parts that can be replaced:

  • HV busbars with Ancillary Bay connector
  • Inlet carrier with puck and latch
  • HV back cover
  • HV back cover busbar brackets
  • Charge port door
  • Charge port ECU
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