LR
All faults
ElectricalMedium severity

Td5 immobiliser stops the engine starting

Will get worse if left.

Symptoms

Engine cranks but does not fire, or will not crank, and the alarm LED flashes rapidly.

Likely cause

Flat key fob battery, lost fob synchronisation, or a fault in the alarm ECU or ECU to body control communication.

Suggested fixes

Listed roughly in the order most owners try them.

  1. 1

    Replace the fob battery and resync

    Fit a new battery, then press the lock button several times close to the vehicle.

    Difficulty:
    Easy DIY
    Cost:
    £ (Under about £50 in parts)
  2. 2

    Use the emergency key code

    The emergency code can be entered using the driver door lock to override the immobiliser.

    Difficulty:
    Easy DIY
    Cost:
    £ (Under about £50 in parts)
  3. 3

    Have the ECU and alarm checked

    A specialist can diagnose communication faults and re-code fobs.

    Difficulty:
    Specialist job
    Cost:
    ££ (About £50 to £300)

This is general guidance gathered from owner experience and workshop practice, not a substitute for a workshop manual or a qualified mechanic. Costs are rough parts-only guides. Brakes, steering and suspension work affects safety, so if in doubt have it checked professionally.

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