B1B27

Code

LAND ROVER B — Body

Key of identifier 25

Brand: LAND ROVER

Type: B — Body

Views: UK: 12 EN: 24 RU: 14

AI status

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Page language: EN

Causes

Key transponder (key ID 25) not programmed or deleted from immobilizer database
Failed or incomplete key programming/teaching procedure
Damaged or worn transponder inside the key fob
Weak or dead key battery preventing transponder signal
Antenna/coils for the immobilizer/keyless entry receiver fault or poor connection
Immobilizer/Body Control Module (BCM)/Keyless Control Module software or memory error

Symptoms

Vehicle displays “Key not recognised” or similar message
Engine fails to start or immobilizer prevents crank/starting
Remote entry or keyless start functions intermittent or non-functional
Immobilizer/indicator warning lamp or message displayed on dash
Only some keys work; the affected key does nothing

What to check

Confirm code with an OBD diagnostic tool that can read manufacturer codes (JLR SDD/IDS or equivalent)
Check operation of other known-good keys to confirm vehicle-side vs key-side fault
Inspect and measure key fob battery voltage; replace battery and retry
Scan relevant modules (BCM, PATS/Immobilizer, Start/Stop module) for additional codes and CAN communication errors
Use dealer-level tool to list programmed key identifiers and check whether ID 25 is present or marked faulty
Visually inspect key fob for damage and for signs of water ingress or physical impact

Signal parameters

Key transponder serial / identifier number (ID 25)
Receiver/antenna signal strength or RSSI
Key battery voltage (V)
Number of keys programmed in immobilizer database
Immobilizer/BCM error counters and status flags
Relevant CAN message IDs and last-seen timestamps (module comms)

Diagnostic algorithm

Read and record all related DTCs from immobilizer, BCM and engine control module using a manufacturer-capable scanner.
Ask owner to present all known keys. Verify which keys are recognized and which are not to isolate whether fault is specific to key ID 25.
Check and, if low, replace the battery in the suspect key fob. Retry recognition/start after battery replacement.
Use dealer-level diagnostic tool to list programmed keys. Verify whether key identifier 25 appears in the key list or is flagged as invalid.
If key ID 25 is missing, perform manufacturer-specified key programming/teach procedure with the suspect key and a known-good key following service manual steps.
If programming fails, inspect/retest the immobilizer antenna/reader: check harness continuity, connector condition and supply/reference voltages at the receiver coil.
Monitor the immobilizer and CAN communications while attempting key enrolment to identify module communication failures.
If the transponder is physically damaged or continues to fail, try using a different spare key or replace the key fob/transponder and program it.
If module memory or software is suspected (repeating failures, many invalid key entries, or post-update issues), consult manufacturer service information for software reflash or module replacement guidance.
Clear codes, retest all keys and record results. If intermittent or unresolved, escalate to dealer-level support or replace faulty component per service manual.

Likely causes

Key battery worn or flat
Key was lost or recently replaced and not programmed
Damaged transponder chip inside the fob
Antenna/reader circuit fault at receiver (poor reception of key ID)
Module memory corruption or software mismatch after updates

Fault status

⚠️ Status

Immobilizer reports key identifier 25 not recognised or failed authentication with the vehicle security module. Key may be unprogrammed, damaged, or communication to immobilizer/reader failed.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0 - 3.0 hours

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Repair manuals

Manual library for LAND ROVER

320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

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