Code
P0673
LAND ROVER
P — Powertrain
Cylinder 3 glow plug open circuit
Views:
UK: 3
EN: 16
RU: 12
AI status
Completed
Completed
100%
Causes
- Failed glow plug (open winding)
- Broken or disconnected wiring to glow plug #3
- Corroded or damaged connector/terminal
- Blown fuse or faulty glow relay/power supply
- Open or high-resistance ground connection
- Faulty ECM/driver circuit (rare)
Symptoms
- Glow plug warning lamp or diesel preheat indicator illuminated
- Hard starting or extended cranking when cold
- Excessive white smoke on cold start
- Rough idle or misfire until engine warms
- Check Engine Light (MIL) set with stored code P0673
What to check
- Read freeze-frame and live data with a diagnostic scanner (confirm code and conditions)
- Visually inspect glow plug #3 connector, wiring, and insulation for damage/corrosion
- Check glow plug fuse(s) and glow relay/power supply for continuity and operation
- Measure resistance of glow plug #3 (engine cold) by removing connector — compare to manufacturer spec
- Backprobe connector with ignition on to verify supply voltage and driver signal from ECM when preheat is active
- Perform wiggle test on harness while monitoring ECU data to detect intermittent opens
Signal parameters
- Typical glow plug resistance (cold): roughly 0.5–2.0 ohms (varies by engine; check OEM spec)
- Supply voltage at connector when energized: near battery voltage (~11–14 V) at feed side
- Driver output: ECM switches ground or positive to allow current flow; expected measurable current draw per plug commonly several amps (varies by design)
- Open circuit condition: infinite or very high resistance on ohmmeter and/or no current/voltage at plug when commanded
Diagnostic algorithm
- Safety first: allow engine to cool, park on level ground, set parking brake. Wear eye protection and insulated gloves when working near battery and heated components.
- Use a scan tool: record freeze-frame, note conditions (battery voltage, coolant temp, ambient temp). Clear code only after repairs for retest.
- Visual inspection: examine glow plug #3, connector, wiring, and ground paths for damage, corrosion, loose pins, or signs of overheating.
- Check fuses/relay: verify supply fuse and glow relay operation. Replace if faulty.
- Measure glow plug resistance: disconnect connector and measure resistance of glow plug #3 to engine ground or across the plug — compare to spec. An open (OL) indicates a failed plug.
- Verify supply and switching: with harness connected, backprobe feed and driver terminals. With preheat commanded, feed should have battery voltage and driver should show switching (ground or voltage change). No feed indicates power supply/fuse/relay issue; feed present but no switching indicates ECM/driver or open in wiring to plug.
- Continuity test: check continuity from ECM/relay to the glow plug connector and from plug connector to engine ground. Repair any open or high-resistance wiring or poor grounds.
- Swap test: when safe and plugs are identical, swap plug #3 with another cylinder. If code moves to that cylinder number, plug is faulty. If code remains P0673, suspect wiring/ECM.
- Repair/replace: replace failed glow plug and/or repair wiring/connector or replace fuse/relay. If ECM driver is suspected after ruling out wiring and plug, consult dealer-level information before ECM replacement.
- Verify: clear codes, perform crank/idle and preheat cycles under similar conditions, confirm code does not return.
- Note: consult Land Rover OEM specs and procedures for torque values, plug type, and exact resistance/voltage values.
Likely causes
- Glow plug #3 has failed open
- Loose/broken lead or pin at the glow plug connector
- Corroded connector or terminal causing open circuit
- Faulty fuse or relay in glow plug feed
- Damage to harness (chafing, heat, rodent bite) between ECM and cylinder 3
Fault status
Status
Cylinder 3 glow plug open circuit — ECM detected an open or very high resistance condition in the glow plug/heater circuit for cylinder 3.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
HTML Workshop Manuals AI manual library for LAND ROVER Click to show available manuals 39
LAND ROVER 2018 Discovery HSE Luxury, 3.0L Eng VIN K
HTML ManualLAND ROVER 2018 Discovery HSE Luxury, 3.0L Eng VIN V
HTML ManualLAND ROVER 2018 Discovery HSE, 3.0L Eng VIN K
HTML ManualLAND ROVER 2018 Discovery HSE, 3.0L Eng VIN V
HTML ManualLAND ROVER 2018 Discovery Sport HSE
HTML ManualLAND ROVER 2018 Discovery Sport HSE Luxury
HTML ManualLAND ROVER 2018 Discovery Sport SE
HTML ManualLAND ROVER 2018 Range Rover Autobiography
HTML ManualWorkshop Manuals
Repair manuals for LAND ROVER
3
Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop Manual199,00 UAH
Land Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)
Workshop Manual199,00 UAH
Land Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)
Workshop Manual199,00 UAH
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
