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Home >> Land Rover >> 2021 >> Defender 110 X >> Repair and Diagnosis (Single Page) >> Quick Lookups >> Common Specs & Procedures >> Diagnostic Trouble Code Index DTC: Transmission Control Module (TCM) For 8HP76/51 Transmission -- Defender/L663 >> Diagnostic Trouble Code Index - DTC: Transmission Control Module (TCM) For 8HP76/51 Transmission (G2413630) >> Description And Operation >> Transmission Control Module (TCM) - 8HP76/51 Transmission >> Notes
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Transmission Control Module (TCM) - 8HP76/51 Transmission: Notes

NOTE: Guided Diagnostics must be followed and the repair advised by the process completed. Failure to do so may result in the rejection of any warranty claim made.

Inspection, Verification and Additional Warnings For Electric Vehicles 

WARNING:
  • ONLY  qualified personnel are permitted to work on electric/hybrid vehicles with High Voltage (HV) systems. Refer to the Electric Vehicle Safety Rules to verify the suitably qualified persons.
  • Any work or testing of components within the High Voltage (HV) system can only be completed when the vehicle has been powered down by an Electric Vehicle Authorized Person (EVAP). Refer to the Electric Vehicle Safety Rules to verify the rules of working with High Voltage (HV) systems. Failure to comply with the correct safety protocols/local legislations when operating the High Voltage (HV) system may result in personal injury or death.
  • A Permit-To-Work must be completed before any work or testing is completed on the High Voltage (HV) system or High Voltage (HV) components. Failure to comply with this instruction may result in personal injury or death.
  • Appropriate PPE must be worn when working on or near an electric vehicle high voltage system. Failure to comply with this instruction may result in personal injury or death.
  • The High Voltage (HV) components must NOT  be disassembled unless otherwise instructed to do so by the approved service information procedure. Failure to comply with this instruction could cause the risk of exposure to High Voltage (HV), resulting in personal injury or death.
  • Any work or testing of the High Voltage (HV) system or components MUST  be in accordance with the approved service information procedure. Failure to comply with this instruction could cause the risk of exposure to High Voltage (HV), resulting in personal injury or death.
  • If the hybrid/EV battery pack is damaged or overcharged, there is a risk of exposure to High Voltage (HV) and/or highly corrosive electrolyte mist. DO NOT  work on the components or the vehicle if liquid or vapor is observed leaking from the hybrid/EV battery pack. Immediately follow the instructions in the Electric Vehicle Quarantine procedure.
  • The High Voltage (HV) system will be live and active if the error message "High Voltage Shutdown Not Possible - System Live" is displayed. This error message will appear if the Battery Energy Module (BEM) cannot isolate the High voltage (HV) system. Be aware that the vehicle is still live with High Voltage (HV). The appropriate signage MUST  be displayed on the vehicle and a Technical Assist (TA) MUST  be raised. Failure to understand this instruction and comply with the High Voltage (HV) regulations may result in personal injury or death.
  • Be aware that a motor generator can generate a voltage if the wheels are rotated, even if the electric vehicle system has been made safe. Failure to comply with this instruction may result in personal injury or death.
CAUTION: Diagnosis by substitution from a donor vehicle is NOT  acceptable. Substitution of control modules does not guarantee confirmation of a fault, and may also cause additional faults in the vehicle being tested and/or the donor vehicle.
NOTE:
  • If a control module or a component is at fault and the vehicle remains under manufacturer warranty, refer to the Warranty Policy and Procedures manual, or determine if any prior approval program is in operation, prior to the installation of a new module/component.
  • Generic scan tools may not read the codes listed, or may read only 5-digit codes. Match the 5 digits from the scan tool to the first 5 digits of the 7-digit code listed to identify the fault (the last 2 digits give extra information read by the Jaguar Land Rover approved diagnostic equipment).
  • When performing voltage or resistance tests, always use a digital multimeter that has the resolution ability to view 3 decimal places. For example, on the 2 volts range can measure 1 mV or 2 kΩ range can measure 1 Ω. When testing resistance always take the resistance of the digital multimeter leads into account.
  • Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.
  • Inspect connectors for signs of water ingress, and pins for damage and/or corrosion.
  • If DTCs are recorded and, after performing the pinpoint tests, a fault is not present, an intermittent concern may be the cause. Always check for loose connections and corroded terminals.
  • Check JLR claims submission system for open campaigns. Refer to the corresponding bulletins and SSMs which may be valid for the specific customer complaint and complete the recommendations as required.
  • Where the Jaguar Land Rover approved diagnostic equipment is not available to check the automatic transmission fluid level, refer to the relevant, 'General Procedures' service information.

The DTC Index lists all Diagnostic Trouble Codes (DTCs) that could be set in the Transmission Control Module (TCM). For additional diagnosis and testing information, refer to the relevant Diagnosis and Testing service information.

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