Code
P1206
LAND ROVER
P — Powertrain
Open circuit / short circuit injection cylinder 6
Views:
UK: 14
EN: 35
RU: 24
AI status
Completed
Completed
100%
Causes
- Damaged or corroded injector wiring harness for cylinder 6 (open, short to ground or short to battery)
- Poor or corroded connector at injector #6 (poor contact, bent pins, water ingress)
- Failed fuel injector (internal short or open winding)
- Blown/poor fuse or relay in the injector power feed circuit
- Faulty ECU/injector driver (internal MOSFET/driver failure)
- Poor engine/ECU ground or power supply
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- Misfire or rough running specifically on cylinder 6
- Reduced engine power, hesitation or poor acceleration
- Rough idle, increased vibration
- Poor fuel economy
- Possible hard start or no start in severe cases
What to check
- Read/record freeze-frame and live data (misfire counts, injector pulse) with a scan tool
- Visually inspect injector #6 connector and harness for damage, corrosion, or oil/water ingress
- Back-probe the injector connector and verify supply voltage with ignition on
- Measure injector coil resistance (compare to OEM spec) and check for short to ground or battery
- Use a noid light or oscilloscope to confirm injector drive pulse while cranking/running
- Wiggle test wiring while monitoring codes/live data to find intermittent faults
Signal parameters
- Injector supply voltage: ~12 V (verify actual battery voltage at harness with ignition on)
- Injector coil resistance: depends on type — typical high-impedance 10–16 Ω, low-impedance 2–4 Ω; check OEM spec
- Injector drive: ECU typically grounds the injector; look for a pulsed ground waveform when cranking/running
- Pulse width: variable with load/RPM — commonly 1–8 ms in normal operating range (consult OEM data for exact values)
- Injector current: typically tens to hundreds of mA for high-impedance, up to several amps for low-impedance drivers; check spec
- Short/open indicators: near 0 Ω suggests short, infinite/very high Ω indicates open/disconnected
Diagnostic algorithm
- Capture freeze-frame and live data: confirm cylinder 6 misfire and note conditions when code set (engine temperature, rpm, load).
- Visual inspection: disconnect ignition, inspect the cylinder 6 injector connector and wiring for corrosion, damage, pin deformation or contamination. Repair any obvious issues.
- Check power supply: back-probe the injector harness with ignition ON and verify constant 12 V (or battery voltage) on the power terminal.
- Check ground/driver pulse: crank/run engine and use a noid light or scope on the injector control wire to confirm ECU is providing a pulsed signal. If no pulse, move to wiring/ECU driver checks.
- Measure resistance: unplug injector and measure coil resistance at the injector terminals. Compare to OEM spec. Replace injector if out of spec.
- Check for shorts/opens: with harness disconnected from injector, check continuity from injector connector to ECU connector and for short to battery or ground. Wiggle harness to detect intermittent failures.
- Swap test: if practical, swap injector #6 with another cylinder’s injector. If code and symptom move with the injector, replace the injector. If code stays on cylinder 6, suspect wiring or ECU.
- Inspect fuses/relays and grounds: verify related fuses/relays and clean/check engine/ECU ground points.
- ECU driver test: if wiring and injector are good, test ECU injector driver outputs with an oscilloscope or consult a specialist; replace ECU only after confirming driver failure.
- Clear codes and road-test: after repairs, clear codes, re-run diagnostics and verify the fault does not return under the same conditions.
Likely causes
- Corroded/loose injector connector at cylinder 6
- Broken or chafed wire in the injector harness (open or short)
- Failed injector (winding open or shorted)
- Intermittent wiring fault caused by vibration or heat
- Less likely: ECU driver failure
Fault status
Status
Open or short detected on fuel injector circuit for cylinder 6 — check injector, connector, wiring and ECU driver.
Repair difficulty: Medium
Diagnostic time: 1.0 - 3.0 hours
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