C1709

Code

LAND ROVER C — Chassis

Left rear central sensor - circuit failure

Brand: LAND ROVER

Type: C — Chassis

Views: UK: 19 EN: 37 RU: 29

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open circuit (broken wire, poor pin contact, disconnected connector)
Short to ground or short to battery (+12V) in sensor wiring
Corroded or pushed-back connector pins or water ingress at connector
Failed sensor element or internal short in sensor
Faulty control module or connector at the module
Blown fuse or poor ground for the sensor circuit

Symptoms

Diagnostic trouble code stored (C1709) and warning lamp or message
Related system degraded or disabled (e.g., parking aid, proximity warnings or vehicle height/ride systems depending on sensor function)
No or incorrect sensor readings shown by scan tool (e.g., no value, erratic values, or constant 0)
Intermittent operation of the affected system when harness is moved
Audible beeps or visual alerts missing on the affected side (for parking sensors)

What to check

Use a diagnostic scanner to read freeze-frame data and confirm C1709; check for additional related codes
Visually inspect the left rear central sensor, mounting, and surrounding wiring for damage, water, or corrosion
Inspect the sensor connector for bent, pushed-back or corroded pins; ensure secure mating
Check fuses and module power/ground circuits related to the sensor
Backprobe the sensor connector with key on to verify reference voltage, ground, and signal
Perform a wiggle test on the wiring while observing live data or watch for code/malfunction change

Signal parameters

Typical supply/reference: 5 V DC (vehicle-specific; some sensors use battery +12 V or ground-switching—verify service manual)
Typical signal output: 0–5 V analog or pulsed output for active sensors; values may be near 0 V for a short-to-ground or near battery voltage for a short-to-ignition/12 V
Passive (variable reluctance) sensors: no DC reference; expect AC pulses when wheel/target moves and DC resistance typically ~500–1500 Ω (model-dependent)
A short to ground will read ~0 V on the signal circuit; a short to 12 V will read near battery voltage (~12 V) with ignition on
Confirm all values with the vehicle-specific repair manual before relying on them

Diagnostic algorithm

Connect a vehicle scan tool, confirm C1709 and note any additional related codes; record live data for the affected sensor.
Visually inspect the sensor, connector and wiring at the left rear central sensor for damage, water ingress or corrosion; repair any obvious faults.
With ignition ON (engine off unless otherwise specified), backprobe connector: verify sensor reference voltage, signal and ground. Compare to known-good values or service data.
Check for continuity between the sensor connector and the control module connector; check for shorts to ground and to battery using an ohm meter (power off, battery disconnected if required).
Wiggle harness and connectors while watching live data or scan tool for intermittent faults; this helps find broken wires or poor contacts.
If the sensor is passive, check DC resistance across the sensor and, if available, use an oscilloscope to verify AC waveform when target moves. For active sensors, verify proper 5 V reference and signal waveform.
If wiring and connector are good, swap the suspect sensor with a known-good unit (if possible) or install a replacement sensor to confirm whether the sensor is faulty.
If sensor replacement doesn't clear the fault, inspect/repair wiring to the control module and check module power/ground and inputs; repair or replace the module only after ruling out harness and sensor.
After repairs, clear codes and retest function and road-test or operate the affected system to ensure the fault does not return.

Likely causes

Corroded or loose connector at the left rear central sensor
Damaged/chafed wiring between the sensor and module (open or short)
Failed sensor
Poor ground or supply to the sensor
Module input fault (less common)

Fault status

⚠️ Status

C1709 — Left rear central sensor circuit failure. Check sensor, connector, wiring and module power/ground.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

Repair manuals

Manual library for LAND ROVER

325

Browse 325 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

C1709 — Left rear central sensor - circuit failure