Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / P0670 — Glow Plug Control Module 1 Control Circuit/Open

P0670 — Glow Plug Control Module 1 Control Circuit/Open

Detailed page for trouble code P0670.

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

P0670

Generic P — Powertrain

Glow Plug Control Module 1 Control Circuit/Open

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

Causes

  • Blown fuse or tripped circuit breaker for glow plug system
  • Open, damaged or corroded wiring/connectors between PCM and glow plug control module
  • Poor or missing ground at glow plug control module
  • Faulty glow plug control module (internal open/failed driver)
  • Faulty PCM or PCM output driver (less common)
  • Open or very high-resistance glow plug(s) or harness

Symptoms

  • Glow plug indicator lamp illuminated or fault lamp (MIL) on
  • Hard cold starting or extended cranking time in cold weather
  • White smoke at cold start, rough idle until engine warms
  • Reduced cold-start performance; possible no glow plug activation
  • Stored P0670 trouble code and possibly related glow-plug codes

What to check

  • Read and record freeze frame and related codes with a scan tool
  • Visually inspect wiring, connectors, and module for corrosion, heat damage, or disconnection
  • Check relevant fuses and any glow-plug relays/circuit breakers
  • Verify battery voltage at the glow plug module supply with key ON and during cranking (should be near battery voltage)
  • Check ground integrity at module mounting point and ground conductor
  • Measure continuity between PCM control output and glow plug control module input

Signal parameters

  • Glow plug supply voltage: approx. battery voltage when key ON/crank (typically 11–14 V)
  • Control signal type: PWM or switched supply/ground from PCM to module (varies by design)
  • Expected control circuit behavior: when commanded, control line will switch (either to battery or ground) — scan tool should show glow plug command active
  • Typical individual glow plug resistance (varies by engine): roughly 0.2–2.0 Ω (consult vehicle spec)
  • Open-circuit condition: infinite/very high resistance between module and glow plugs or between PCM and module

Diagnostic algorithm

  1. Verify the P0670 code and note any related codes (P0671–P0678 etc.) using a scan tool
  2. Inspect fuse(s) and relay(s) protecting the glow plug circuit; replace any blown fuses and retest
  3. Visually inspect glow plug control module, connectors and harness for corrosion, damage, or loose pins; repair as needed
  4. With key ON, measure supply voltage at the glow plug control module power terminal — confirm battery voltage present
  5. Check module ground for good continuity to battery negative; repair any poor ground
  6. Using a digital meter, check continuity of the control circuit between the PCM control output and the glow plug control module input; repair open circuits
  7. Measure resistance of each glow plug to identify open or very high-resistance plugs; replace any failed glow plugs
  8. If wiring, fuses and glow plugs are good, test or bench-check the glow plug control module; replace module if internal open/failed
  9. If replacement module still shows open or fault, test PCM control output for proper function; consult manufacturer procedures before replacing PCM
  10. Clear codes, perform a cold-start test and confirm glow plug operation and that P0670 does not return

Likely causes

  • Blown fuse or disconnected battery feed to the glow plug module
  • Open/damaged wiring or corroded connector at glow plug control module
  • Failed glow plug control module
  • High-resistance or open glow plug or harness causing circuit open

Fault status

⚠️ Status
P0670 - Glow Plug Control Module 1 Control Circuit/Open. Open or interrupted circuit to glow plug control module; glow plug operation may be disabled. MIL on.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

P0671 P0672 P0673 P0674 P0675 P0676
9,128

The library contains 9,128 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
193
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
2,063
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

P0670

LAND ROVER P — Powertrain

Control module circuit of the glow plug

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

Causes

  • Blown fuse or tripped circuit breaker for glow plug system
  • Open, damaged or corroded wiring/connectors between PCM and glow plug control module
  • Poor or missing ground at glow plug control module
  • Faulty glow plug control module (internal open/failed driver)
  • Faulty PCM or PCM output driver (less common)
  • Open or very high-resistance glow plug(s) or harness

Symptoms

  • Glow plug indicator lamp illuminated or fault lamp (MIL) on
  • Hard cold starting or extended cranking time in cold weather
  • White smoke at cold start, rough idle until engine warms
  • Reduced cold-start performance; possible no glow plug activation
  • Stored P0670 trouble code and possibly related glow-plug codes

What to check

  • Read and record freeze frame and related codes with a scan tool
  • Visually inspect wiring, connectors, and module for corrosion, heat damage, or disconnection
  • Check relevant fuses and any glow-plug relays/circuit breakers
  • Verify battery voltage at the glow plug module supply with key ON and during cranking (should be near battery voltage)
  • Check ground integrity at module mounting point and ground conductor
  • Measure continuity between PCM control output and glow plug control module input

Signal parameters

  • Glow plug supply voltage: approx. battery voltage when key ON/crank (typically 11–14 V)
  • Control signal type: PWM or switched supply/ground from PCM to module (varies by design)
  • Expected control circuit behavior: when commanded, control line will switch (either to battery or ground) — scan tool should show glow plug command active
  • Typical individual glow plug resistance (varies by engine): roughly 0.2–2.0 Ω (consult vehicle spec)
  • Open-circuit condition: infinite/very high resistance between module and glow plugs or between PCM and module

Diagnostic algorithm

  1. Verify the P0670 code and note any related codes (P0671–P0678 etc.) using a scan tool
  2. Inspect fuse(s) and relay(s) protecting the glow plug circuit; replace any blown fuses and retest
  3. Visually inspect glow plug control module, connectors and harness for corrosion, damage, or loose pins; repair as needed
  4. With key ON, measure supply voltage at the glow plug control module power terminal — confirm battery voltage present
  5. Check module ground for good continuity to battery negative; repair any poor ground
  6. Using a digital meter, check continuity of the control circuit between the PCM control output and the glow plug control module input; repair open circuits
  7. Measure resistance of each glow plug to identify open or very high-resistance plugs; replace any failed glow plugs
  8. If wiring, fuses and glow plugs are good, test or bench-check the glow plug control module; replace module if internal open/failed
  9. If replacement module still shows open or fault, test PCM control output for proper function; consult manufacturer procedures before replacing PCM
  10. Clear codes, perform a cold-start test and confirm glow plug operation and that P0670 does not return

Likely causes

  • Blown fuse or disconnected battery feed to the glow plug module
  • Open/damaged wiring or corroded connector at glow plug control module
  • Failed glow plug control module
  • High-resistance or open glow plug or harness causing circuit open

Fault status

⚠️ Status
P0670 - Glow Plug Control Module 1 Control Circuit/Open. Open or interrupted circuit to glow plug control module; glow plug operation may be disabled. MIL on.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

P0671 P0672 P0673 P0674 P0675 P0676
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 .