Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / P0673 — Cylinder 3 Glow Plug Circuit/Open

P0673 — Cylinder 3 Glow Plug Circuit/Open

Detailed page for trouble code P0673.

34,405codes
59brands
11,914generic
22,491specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

P0673

Generic P — Powertrain

Cylinder 3 Glow Plug Circuit/Open

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

Causes

  • Failed/open glow plug (cylinder 3)
  • Broken or disconnected wiring/harness to glow plug
  • Corroded or loose connector at the glow plug
  • Faulty glow plug relay or fuse (power feed)
  • High resistance in circuit (poor connection, corrosion, heat damage)
  • Faulty ECM/driver output (less common)

Symptoms

  • Hard starting when cold (diesel engines)
  • Longer glow time or extended cranking on cold starts
  • Rough or uneven idle after cold start
  • White smoke or excessive smoke during cold start
  • MIL/Check Engine light illuminated with stored P0673
  • Possible reduced fuel economy or increased emissions until warmed

What to check

  • Read codes and freeze frame data with a scan tool; note related glow or preheat codes
  • Visual inspection of glow plug harness, connector, and wiring at cylinder 3 for damage or corrosion
  • Verify glow plug fuse(s) and relay operation
  • Back-probe connector during glow cycle to confirm presence of battery voltage at the plug
  • Measure resistance of the glow plug (bench test with plug removed) and compare to specification
  • Check continuity from glow plug connector to ECM/relay and verify ground path

Signal parameters

  • Expected voltage during preheat: approximately battery voltage (~11–14 V) at the glow plug connector (when relay is energized)
  • Normal glow plug resistance: typically low (often under ~2 ohms) — reading open/infinite indicates failure
  • Open-circuit condition: infinite/OL resistance or no current draw from the plug
  • High-resistance condition: measurable but significantly above specification (may cause reduced heat and trigger P0673)
  • Current draw: varies by design (single-digit to low double-digit amps per plug); a dramatic reduction or no current indicates a fault

Diagnostic algorithm

  1. Verify: Connect a scanner, record freeze frame and related codes. Note if other glow-related codes are present.
  2. Inspect: Perform a visual inspection of the cylinder 3 glow plug, connector, and wiring for corrosion, damage, burns or loose terminals.
  3. Power supply: Check glow plug fuse(s) and operation of glow relay/driver. Replace fuse or relay if faulty and retest.
  4. Voltage test: With the key in preheat position (or commanded preheat via scan tool), back-probe the cylinder 3 connector and confirm battery voltage is present. No voltage suggests relay/fuse/ECM driver issue.
  5. Resistance test: With the glow plug removed, measure resistance between the glow-plug terminal and its body/ground. An open (infinite) or out-of-spec high reading indicates a bad glow plug — replace if faulty.
  6. Continuity test: Check continuity between the glow plug connector and the relay/ECM output to find breaks in the wiring. Repair any open or high-resistance wiring or poor grounds.
  7. Isolation test: If in doubt, swap the cylinder 3 glow plug with another cylinder’s glow plug (if vehicle design allows) and see if the fault follows the plug or stays on cylinder 3. This helps distinguish a plug vs. harness/ECM issue.
  8. ECM/driver check: If wiring, fuse, relay and plug are good but code remains, test ECM output driver circuit per manufacturer procedure or consult a specialist — ECM driver faults are less common.
  9. Repair and verify: Replace faulty glow plug(s), repair wiring/connectors, replace relay/fuse as required. Clear codes and perform multiple cold start cycles to confirm the fault is resolved.
  10. Safety: Disconnect battery when performing connector/wire repairs or replacing components where required by manufacturer procedures.

Likely causes

  • Open or internally failed glow plug on cylinder 3
  • Damaged/strained wiring or a disconnected connector at cylinder 3
  • Corroded connector or poor ground causing high resistance
  • Blown fuse or faulty relay supplying the glow plug bank

Fault status

⚠️ Status
ECM detected an open or interrupted glow plug circuit for cylinder 3 — no expected current/voltage during preheat or monitoring. The engine may experience hard cold starts or uneven running until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2 hours

Similar codes

P0670 P0671 P0672 P0674 P0675 P0385
8,958

The library contains 8,958 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

ALFA ROMEO
89
AUDI
1,243
BMW
479
CADILLAC
206
CHEVROLET
456
CHRYSLER
44
DAEWOO
75
FIAT
26
GENESIS
207
HUMMER
138
HYUNDAI
371
ISUZU
86
LAND ROVER
320
LEXUS
280
LINCOLN
166
MERCEDES-BENZ
856
MERCURY
296
MITSUBISHI
406
PORSCHE
136
TESLA
58
TOYOTA
2,042
TRIUMPH
131
VOLKSWAGEN
626
VOLVO
221
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P0673

LAND ROVER P — Powertrain

Cylinder 3 glow plug open circuit

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

Causes

  • Failed/open glow plug (cylinder 3)
  • Broken or disconnected wiring/harness to glow plug
  • Corroded or loose connector at the glow plug
  • Faulty glow plug relay or fuse (power feed)
  • High resistance in circuit (poor connection, corrosion, heat damage)
  • Faulty ECM/driver output (less common)

Symptoms

  • Hard starting when cold (diesel engines)
  • Longer glow time or extended cranking on cold starts
  • Rough or uneven idle after cold start
  • White smoke or excessive smoke during cold start
  • MIL/Check Engine light illuminated with stored P0673
  • Possible reduced fuel economy or increased emissions until warmed

What to check

  • Read codes and freeze frame data with a scan tool; note related glow or preheat codes
  • Visual inspection of glow plug harness, connector, and wiring at cylinder 3 for damage or corrosion
  • Verify glow plug fuse(s) and relay operation
  • Back-probe connector during glow cycle to confirm presence of battery voltage at the plug
  • Measure resistance of the glow plug (bench test with plug removed) and compare to specification
  • Check continuity from glow plug connector to ECM/relay and verify ground path

Signal parameters

  • Expected voltage during preheat: approximately battery voltage (~11–14 V) at the glow plug connector (when relay is energized)
  • Normal glow plug resistance: typically low (often under ~2 ohms) — reading open/infinite indicates failure
  • Open-circuit condition: infinite/OL resistance or no current draw from the plug
  • High-resistance condition: measurable but significantly above specification (may cause reduced heat and trigger P0673)
  • Current draw: varies by design (single-digit to low double-digit amps per plug); a dramatic reduction or no current indicates a fault

Diagnostic algorithm

  1. Verify: Connect a scanner, record freeze frame and related codes. Note if other glow-related codes are present.
  2. Inspect: Perform a visual inspection of the cylinder 3 glow plug, connector, and wiring for corrosion, damage, burns or loose terminals.
  3. Power supply: Check glow plug fuse(s) and operation of glow relay/driver. Replace fuse or relay if faulty and retest.
  4. Voltage test: With the key in preheat position (or commanded preheat via scan tool), back-probe the cylinder 3 connector and confirm battery voltage is present. No voltage suggests relay/fuse/ECM driver issue.
  5. Resistance test: With the glow plug removed, measure resistance between the glow-plug terminal and its body/ground. An open (infinite) or out-of-spec high reading indicates a bad glow plug — replace if faulty.
  6. Continuity test: Check continuity between the glow plug connector and the relay/ECM output to find breaks in the wiring. Repair any open or high-resistance wiring or poor grounds.
  7. Isolation test: If in doubt, swap the cylinder 3 glow plug with another cylinder’s glow plug (if vehicle design allows) and see if the fault follows the plug or stays on cylinder 3. This helps distinguish a plug vs. harness/ECM issue.
  8. ECM/driver check: If wiring, fuse, relay and plug are good but code remains, test ECM output driver circuit per manufacturer procedure or consult a specialist — ECM driver faults are less common.
  9. Repair and verify: Replace faulty glow plug(s), repair wiring/connectors, replace relay/fuse as required. Clear codes and perform multiple cold start cycles to confirm the fault is resolved.
  10. Safety: Disconnect battery when performing connector/wire repairs or replacing components where required by manufacturer procedures.

Likely causes

  • Open or internally failed glow plug on cylinder 3
  • Damaged/strained wiring or a disconnected connector at cylinder 3
  • Corroded connector or poor ground causing high resistance
  • Blown fuse or faulty relay supplying the glow plug bank

Fault status

⚠️ Status
ECM detected an open or interrupted glow plug circuit for cylinder 3 — no expected current/voltage during preheat or monitoring. The engine may experience hard cold starts or uneven running until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2 hours

Similar codes

P0670 P0671 P0672 P0674 P0675 P0385
320

Browse 320 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 .