Autopapyrus · Land Rover Discovery Sport (Facelift, L550)
https://autopapyrus.com/guides/land-rover/discovery-sport/srs-system-diagnostics-and-reading-airbag-fault-codes/
https://autopapyrus.com/guides/land-rover/discovery-sport/srs-system-diagnostics-and-reading-airbag-fault-codes/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.
Land Rover Discovery Sport (Facelift, L550): SRS System Diagnostics and Reading Airbag Fault Codes
A lit SRS warning light on the instrument cluster means the RCM has detected a fault in the airbag circuits, pretensioners, impact sensors or seat occupancy sensor. To find the cause, first read the codes over CAN with a scan tool, then check the connectors and harnesses under the seats, and only then replace parts.
Parts
6| № | Part |
|---|---|
| 01 | Steering wheel clockspring (spiral cable)if faulty |
| 02 | Front seat position/occupant detection sensorif faulty |
| 03 | Impact sensor (side or front)if faulty |
| 04 | Seat belt pretensionerif faulty |
| 05 | Under-seat harness connectorif faulty |
| 06 | Restraints Control Module (RCM) assemblyif faulty |
Tools
5- Diagnostic scan tool with Land Rover SRS/RCM support (a generic ELM327 adapter with general OBD software often cannot see the SRS module)
- multimeter
- sockets and wrenches for the battery terminals
- flashlight
- insulated gloves not required
There's a full repair manual for this car
Every system, wiring diagrams and torque specs — not just this job. Haynes AutoFix (online).
See manuals →
Step by step
10 steps- Document the symptoms: whether the SRS light is on steadily or flashing, whether there is a message on the display, and when it first appeared (after a car wash, upholstery cleaning, seat swap, collision, or battery discharge). Check the battery voltage: when voltage sags, the module often logs false power-supply faults.
- Locate the OBD diagnostic port under the dashboard on the driver's side. Connect the scan tool with the ignition on (do not start the engine) and select the RCM module (Restraints Control Module / airbag control module).
- Read all codes, including "permanent" and "current" ones, and save them (write them down or take a screenshot) before erasing anything. Separately, review the codes in other modules: communication, power supply and U-type messages (for example, U0154, lost communication with the occupant sensor module) often lead to SRS faults.
- Identify the fault group from the code: driver or passenger airbag circuit, side airbags and curtains, pretensioners, impact sensors, steering wheel clockspring, seat occupancy sensor, or power supply/communication with the RCM. Remember that a code points to a circuit, not necessarily to a specific part.
- Prepare for the inspection: turn the ignition off, disconnect the negative battery terminal and wait at least 1-2 minutes (preferably 5-10) for the module's backup capacitors to discharge. Do not disconnect any airbag or pretensioner connectors without doing this.
- Inspect the harnesses and connectors under the front seats: on this vehicle they are the most common source of faults. Look for yellow SRS connectors, signs of corrosion, chafed insulation, locking tabs that are not fully latched, and traces of spilled liquids. Slide the seat forward and back without unplugging anything and make sure the harness is not stretched.
- If the code relates to the steering wheel circuit, check the clockspring in the steering column (signs: the fault disappears when the wheel is turned, or the steering wheel buttons do not work). If the code relates to the occupancy sensor, check for foreign objects under the seat and for non-original seat covers or aftermarket seat heaters.
- Do not measure the resistance of airbag circuits with a multimeter or "buzz out" the squibs: the multimeter's test current can deploy the airbag. Only check the harnesses and connectors on the supply side with the airbags disconnected, and only if a specialist with SRS diagnostic experience is not available.
- After fixing the cause, reconnect the battery, turn the ignition on and wait for the SRS light to complete its self-test and go out (usually a few seconds). Then use the scan tool to clear the RCM codes and read them again: the codes must not return. If the light goes out but the code returns after a drive, the fault is intermittent, so check the connectors again.
- If the RCM does not respond, if the code points to an internal module fault, or if a deployment event has been recorded (after a collision), the module and any deployed components must be replaced, followed by coding and pairing with the repair shop's equipment. Do not attempt to replace such a module yourself.
Common mistakes and warnings
- The SRS system contains pyrotechnic components: never disassemble airbags, pretensioners or the clockspring, never drop or puncture them, and never check for voltage at airbag connectors with the battery connected
- Have any work on the airbags themselves, on the RCM, and anything after a collision done only at a repair shop
- If the SRS light is on, the airbags may not deploy in a crash, so do not put off diagnosis
- Do not erase codes without fixing the cause: doing so hides the fault and does not restore protection