Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / P0309 — ignition failure of Cylinder 9 detected

P0309 — ignition failure of Cylinder 9 detected

Detailed page for trouble code P0309.

34,766codes
59brands
11,925generic
22,841specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

P0309

LAND ROVER P — Powertrain

ignition failure of Cylinder 9 detected

Brand: LAND ROVER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty ignition coil for cylinder 9
  • Worn or fouled spark plug in cylinder 9
  • Fuel injector malfunction (stuck/plugged or electrical fault) for cylinder 9
  • Low cylinder compression (mechanical issue: valves, piston, head gasket)
  • Wiring or connector fault to coil or injector (open, short, high resistance)
  • Fuel delivery problem (low fuel pressure, clogged rail, blocked injector)

Symptoms

  • Illuminated MIL (check engine light)
  • Rough idle or engine shaking, especially at idle
  • Loss of power, hesitation, or poor acceleration under load
  • Decreased fuel economy
  • Possible audible popping or exhaust irregularities

What to check

  • Read and record freeze frame and freeze data, stored misfire counters and related codes
  • Check live data for misfire counts per cylinder (cylinder contribution/individual misfire counters)
  • Scan for related codes: injector/ignition circuit faults, fuel trim, cam/crank sensor codes
  • Visually inspect spark plug and coil for carbon tracking, oil contamination, cracks
  • Swap ignition coil (or coil pack) between cylinder 9 and a known good cylinder to see if misfire follows
  • Swap or activate injector between cylinder 9 and another cylinder to see if misfire follows the injector

Signal parameters

  • Cylinder 9 misfire counter (events/min or misfire count per drive cycle)
  • Long-term and short-term fuel trim (LTFT/STFT) at idle and load
  • Oxygen sensor/HEGO voltages and response time (to confirm downstream combustion)
  • Crankshaft position sensor and camshaft position sensor signals/timing
  • Fuel rail pressure (static and during cranking/idle/load)
  • Injector pulse width and duty cycle for cylinder 9

Diagnostic algorithm

  1. Retrieve codes, freeze frame and live misfire counters. Confirm P0309 is active and note conditions (RPM, load, engine temp).
  2. Visually inspect coil, plug, and injector wiring and connectors for damage, corrosion or oil contamination.
  3. With ignition off, remove spark plug from cylinder 9 and inspect condition (electrode wear, fouling, oil). Replace if suspect.
  4. If coil-on-plug, swap the coil from cylinder 9 with a known good cylinder. Clear codes and road test to see if misfire follows the coil.
  5. If misfire follows coil, replace the faulty ignition coil. If not, swap the fuel injector with a known good cylinder and retest to see if misfire follows injector.
  6. Check injector operation: measure resistance, verify injector pulse with a noid light or oscilloscope, and perform a balance test if available.
  7. Measure fuel rail pressure and inspect fuel filter/system for restrictions that could affect that cylinder.
  8. Perform compression and/or leak-down test on cylinder 9 and compare to adjacent cylinders. Diagnose mechanical faults if compression is low.
  9. Use an oscilloscope to check coil primary/secondary waveforms and crank/cam sensor signals for irregularities that could cause timing/misfire.
  10. Inspect for intake manifold or vacuum leaks near cylinder 9; repair leaks and retest.
  11. After repairs or parts replacement, clear codes and perform a road/drive cycle to confirm the misfire has been resolved and no related codes return.
  12. If intermittent or unresolved, consider ECM diagnostics, updates or consult vehicle-specific technical service information.

Likely causes

  • Ignition coil failure for cylinder 9 (most common on coil-on-plug systems)
  • Faulty spark plug or degraded spark (gap, fouling)
  • Injector electrical or mechanical failure causing no/low fuel
  • Wiring/connectors corroded or intermittent to coil/injector
  • Low compression on cylinder 9 due to valve or gasket issue

Fault status

⚠️ Status
Misfire detected on Cylinder 9. DTC P0309 set when the engine control module detects excessive ignition misfire events attributed to cylinder 9. MIL set and driveability symptoms may be present until fault is resolved.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0 - 2.5 hours

Similar codes

P0300 P0301 P0302 P0303 P0304 P0305
413

Browse 413 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 :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .