C1A59

Code

LAND ROVER C — Chassis

Seat Occupancy Sensor Circuit Fault

Brand: LAND ROVER

Type: C — Chassis

Views: UK: 13 EN: 24 RU: 14

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open or short in seat occupancy sensor wiring or connector
Corroded or contaminated seat connector or sensor contacts
Failed seat occupancy sensor (seat mat/pad)
Faulty Occupant Detection Module (ODM) or restraint control module
Water ingress or mechanical damage to the seat cushion/sensor
Aftermarket seat cover or foam changes affecting sensor operation

Symptoms

Airbag warning lamp or SRS/ABS light illuminated
Passenger airbag may be disabled or will not deploy (status message)
Incorrect passenger presence/seatbelt warning message
Seatbelt reminder chime behaves incorrectly
DTC stored in Occupant Detection/Restraint module

What to check

Read and record all related DTCs from restraint/occupant detection modules (use OEM scanner)
Visual inspection of seat underside, connectors and wiring for damage, corrosion or water
Check fuses and power supply to the occupant detection module
Check for recent work or aftermarket seat covers/repairs
Verify software/calibration status and TSBs or recalls for occupant detection

Signal parameters

Supply/reference voltage: typically 5V (verify with OEM data)
Sensor signal voltage: 0–5 V range expected — specific steady/loaded values vary by design
Open-circuit: very high resistance or infinite (no continuity)
Short-circuit: near 0 Ω to ground or to supply indicates short
Typical seat mat resistances vary by design; change in resistance when occupant present is expected — consult OEM resistance table

Diagnostic algorithm

Read all stored codes and freeze frame data from restraint/occupant modules with an OEM-capable scanner; note related codes.
Clear codes, then reproduce condition to confirm C1A59 returns.
Perform visual inspection of the passenger seat underside: connectors, harness routing, chafe points, signs of moisture or damage.
With ignition on, measure reference voltage at the seat occupancy sensor connector (compare to OEM spec; typically 5V).
Backprobe the sensor signal and ground pin; monitor signal while applying weight to the seat and removing it. Look for expected change (0–5V range) or open/short.
Check continuity between seat connector and occupant detection module; verify wiring integrity and resistance to ground/supply for shorts.
Disconnect the seat mat sensor and check for proper open/short conditions per OEM diagnostics. Replace or repair if sensor shows out-of-spec resistance or no response.
Inspect and, if necessary, clean connector pins and apply dielectric grease; reseat connectors securely.
If wiring and sensor check OK, scan for and apply any ECU software updates and perform occupant sensor calibration/relearn procedure per manufacturer.
If fault persists, consider swapping with a known-good seat module/sensor (if available) or replace the occupant detection module following safety procedures. Always follow OEM airbag disable/removal precautions (disconnect battery, wait specified time) before handling seat or SRS components.

Likely causes

Damaged wiring harness under the seat (pinched by seat adjuster)
Loose or corroded connector at the seat occupant sensor or module
Faulty seat mat sensor element due to age or moisture
Faulty seat occupancy module or related ECU
Recent seat removal/installation not reconnected or incorrectly routed

Fault status

⚠️ Status

Seat Occupancy Sensor Circuit Fault — electrical fault detected in passenger seat occupancy sensing circuit (sensor, wiring, connector or control module). May affect passenger airbag enable/disable and seatbelt reminder.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

Repair manuals

Manual library for LAND ROVER

160

Browse 160 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

Your experience will help others

+100 karma for a short comment :)

Was this AI description helpful?

Your feedback helps improve AI descriptions.

👍 Like 0 👎 Dislike 0

Send to email