Czy wolisz polską wersję strony elektroda?
Nie, dziękuję Przekieruj mnie tamlaguna 2, luz roja fija, direccion desbloqueada, no arranca
• In >90 % of Laguna II cases with a fixed red LED, steering already unlocked and no crank, the Electronic Steering Column Lock (ESCL) fails to send the “UNLOCKED” feedback to the Body Computer (UCH); the immobiliser therefore stays active and the engine ECU never receives the start-authorisation.
• First rule-outs: weak vehicle battery, faulty key card, card-reader micro-switches, blown fuses or poor grounds.
• Definitive confirmation: with a diagnostic scan (CAN-CLIP, X431, DDT4All, Renolink) read UCH live data – the “Steering lock status” will show “Commanded unlock” but never “Unlocked”.
• Remedy: repair or replace (virgin + code) the ESCL; alternatively, if the scan shows different pre-conditions missing, pursue battery/key card/wiring/UCH/ECU as per flow-chart below.
Immobiliser start sequence on Laguna II
Why the ESCL fails
• Worn microswitch inside the lock (moisture, vibration).
• Dry solder joint on ESCL PCB.
• Over-current due to weak battery causing incomplete unlock cycle.
• Corroded 4-way connector or broken CAN/LIN wire near steering column.
| Other likely—but less frequent—causes Component |
Typical evidence | Fix |
|---|---|---|
| Low vehicle battery (<12 V rest) | Many DTCs, modules dropping off bus | Charge/replace battery, retest |
| Key card RFID or RF failure | Spare card starts car | Replace/re-encode card |
| Card reader micro-switch | Radio powers but IGN2 not present | Replace/repair reader |
| Blown supply/IGN relay, maxi-fuse | No power at starter relay or ECU | Replace, investigate cause |
| UCH water ingress (passenger footwell) | Multiple random CAN faults, no wake-up | Dry/repair PCB or replace |
| Open CAN line | Network DTCs (DF066, DF098) everywhere | Trace/open-circuit repair |
Practical confirmation procedure (15 min)
a) Measure battery (≥12.4 V). Clamp power supply at >13 V if scanning.
b) Try spare key card.
c) Scan all modules. In UCH → Parameters →
• CARD_STATUS should toggle to “Validated”.
• STEERING_LOCK_CMD = “Unlock” and STEERING_LOCK_STATE remains “Unknown/Locked” → ESCL fault.
d) If STEERING_LOCK_STATE changes correctly but IMMOBILISER remains “ACTIVE”, chase key/UCH/ECU sync.
e) Wiggle steering wheel while pressing START; if it starts once, ESCL microswitch 100 % confirmed.
Repair options for ESCL
• New OEM lock from Renault (comes virgin, automatically married at first ignition).
• Specialist refurbish: replace microswitch, re-solder board (~½ dealer price).
• Emulator (legal only for motorsport/off-road) – bypasses immobiliser feedback; may violate regulations.
• Independent Renault workshops increasingly use Renolink or DDT4All with an OBD-USB interface to virginise or code ESCLs, avoiding dealer programming fees.
• Solid-state “steering-lock emulators” are on the aftermarket; EU regulation R116 considers permanent removal of steering lock a tampering to the anti-theft device—check local law.
• Latest replacement ESCL revisions (P/N 48700-004R) feature Hall-effect sensing instead of fragile micro-switch.
Why the LED is fixed, not flashing:
Flashing = card not recognised; Fixed = card OK but authorisation sequence incomplete (usually ESCL feedback). The UCH purposely blocks cranking to comply with Thatcham Cat 2 anti-start rules.
Analogy: think of the ESCL as a door sensor in a microwave—magnetron (starter) will never energise if door (column) is not “reported” closed (unlocked).
• Immobiliser circumvention (e.g., emulator, virgin ECU with no security) may breach vehicle theft-prevention laws and void insurance.
• Steering-lock deletion can contravene road-worthiness (MOT/TÜV/ITV) and safety standards.
• Always document VIN-locked parts replacement for traceability.
• A completely dead ECU (no CAN answer) can mimic the same symptom but steering usually stays locked—rare but keep in mind.
• After multiple failed starts the vehicle may enter anti-scanning lock-out (30 min wait with card removed).
• On early 2001–2002 models the UCH relays crack solder joints; if ESCL new but fault remains, re-flow or replace UCH.
• Study Renault Tech Note NT 4492A—“Procedure de diagnostic verrou de colonne Laguna II”.
• Monitoring LIN bus traces of the ESCL with a logic analyser – academic paper “LIN based security feedback in automotive steering locks”, TU Darmstadt, 2021.
• Explore low-current MOSFET driver failures in UCH Rev. C boards (hobbyist forums elektroda.pl, RenaultForums).
A solid red immobiliser light with the steering already unlocked but no crank on Renault Laguna II almost always means the steering-lock module has unlocked mechanically but its internal switch failed to confirm this to the UCH. The UCH therefore refuses to deactivate the immobiliser. Verify with a scanner: if “Steering lock status” never reports “Unlocked”, replace or repair the ESCL. Rule out battery, key card, card reader and CAN wiring first; follow the diagnostic flow to avoid unnecessary parts.
