P067D — Cylinder 5 Glow Plug Control Circuit High

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK Safe to drive once the engine is started and warmed up. The main risk is cold-weather starting: with several dead plugs the engine may not start on a cold morning. Fix before winter.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm P067D is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the diesel glow plug system for damage, corrosion, chafing or poor contact.
Subsystem check With the cylinder 5 glow plug control disconnected, measure signal voltage at the harness connector: a high reading with the component unplugged indicates a short to power in the harness; if it drops to normal, the component itself is faulty.
Subsystem check Measure resistance of each glow plug — an open plug reads infinite resistance.
Subsystem check Check voltage at the glow plug rail during the pre-glow phase.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P067D does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P067D (parts and labor, USD, independent shop rates): Replace the glow plug relay/module: $150–$450; Replace one glow plug: $80–$200; Replace a full set of glow plugs: $250–$600. Overall, fixing P067D usually costs between $80 and $600. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Is it safe to drive with P067D?

Safe to drive once the engine is started and warmed up. The main risk is cold-weather starting: with several dead plugs the engine may not start on a cold morning. Fix before winter.

How much does it cost to fix P067D?

Replace the glow plug relay/module — $150–$450; Replace one glow plug — $80–$200; Replace a full set of glow plugs — $250–$600. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What is the most common cause of P067D?

The most common causes are: faulty glow plug relay or control module, blown fuse in the glow plug circuit, damaged glow plug wiring or connector.

How do I diagnose P067D myself?

Start with a scan: confirm P067D, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the cylinder 5 glow plug control, and verify the suspect component against live data before buying parts.

What does OBD2 code P067D mean?

Cylinder 5 Glow Plug Control Circuit High (P067D): a powertrain (engine/transmission) fault affecting the diesel glow plug system. The car is usually drivable while you plan the repair. Most often caused by faulty glow plug relay or control module, blown fuse in the glow plug circuit, damaged glow plug wiring or connector.

Diesel engines rely on glow plugs to ignite the fuel-air mixture during cold starts. These small heating elements sit inside each cylinder and warm the combustion chamber so the engine can fire reliably when temperatures drop. The engine control module manages this process by energizing each glow plug through individual control circuits. When the module detects that the voltage on cylinder 5's control circuit exceeds the normal operating range—typically reading near battery voltage instead of the expected pulsed signal—it triggers OBD2 code P067D. This circuit-high condition tells the ECU that something is pulling the cylinder 5 glow plug signal high, preventing proper control.

The glow plug system operates through the powertrain control module, which monitors voltage feedback on each cylinder's dedicated circuit. When you turn the key, the module activates the glow plugs for a preset period based on coolant temperature and battery voltage. After the pre-heat phase, it switches to a monitoring mode, watching for correct voltage patterns. If P067D appears, the module has confirmed the fault across multiple drive cycles and logged the conditions in freeze frame data. This stored snapshot shows RPM, engine load, temperature, and vehicle speed at the moment the problem was detected, giving you a starting point for diagnosis.

P067D specifically targets cylinder 5. On inline engines, cylinders count from the front belt end toward the transmission. V-engine numbering varies by manufacturer, so consult your firing-order diagram to locate the correct cylinder. Accessibility differs significantly—some cylinders sit behind the intake manifold or require special tools, which directly impacts labor time and repair costs.

Common Symptoms of P067D

When cylinder 5's glow plug control circuit reads high, the effects typically appear during cold operation:

Rough idle that smooths out once the engine reaches operating temperature
Difficulty starting the engine in cold weather conditions
White smoke billowing from the exhaust after a cold start
Glow plug warning light remaining illuminated on the dashboard
Check Engine Light staying on

The white smoke occurs because unburned fuel passes through the cylinder without adequate ignition heat, carrying directly into the exhaust stream.

What Causes P067D?

Circuit-high conditions on the cylinder 5 glow plug control stem from several possible failures, listed from most to least common:

Failed cylinder 5 glow plug internally shorted, pulling the signal line high
Signal wire to cylinder 5 shorted to a power source such as battery positive
Open ground return path for the cylinder 5 glow plug control circuit
Damaged wiring harness or loose connector at the glow plug
Faulty glow plug relay or control module affecting the circuit
Corroded or water-damaged connectors at the glow plug location
Burned-out glow plug with internal short causing elevated voltage

How to Diagnose P067D

Systematic diagnosis prevents unnecessary part replacements. Follow these steps to isolate the root cause of P067D:

Connect an OBD2 scanner, retrieve code P067D, and record all freeze frame data. This information shows the exact conditions—RPM, load, temperature, speed—when the fault occurred and guides your inspection.
Check for related diagnostic trouble codes. Co-occurring codes often reveal the true source, such as short circuits in adjacent cylinders or module communication failures.
Consult manufacturer technical service bulletins for your specific make and model. Many P0xxx codes have documented fixes, software updates, or known issues.
Visually inspect the wiring harness and connectors feeding the cylinder 5 glow plug. Look for chafed insulation, corrosion, broken wires, or loose terminals that could cause a short to power.
With the cylinder 5 glow plug disconnected, measure voltage at the harness connector. High voltage present with the component unplugged confirms a harness short. Voltage dropping to normal levels indicates a failed glow plug.
Test individual glow plug resistance using a multimeter. An open element reads infinite resistance and requires replacement.
Clear P067D after repairs, complete a full drive cycle matching the freeze frame conditions, and verify the code does not return.

Repair Options for P067D

Address the cheapest and most likely causes before replacing expensive components. The appropriate fix depends on your diagnosis:

Replace the glow plug relay or control module: $150–$450
Replace a single cylinder 5 glow plug: $80–$200
Replace the complete glow plug set: $250–$600

How Much Does It Cost to Fix P067D?

Total repair costs depend entirely on which part failed. At independent shop rates in the United States, typical scenarios for P067D include parts and labor:

If the glow plug relay or module is faulty, expect to pay between $150 and $450 depending on your vehicle and local labor rates.
If only the cylinder 5 glow plug itself failed, the repair typically runs $80 to $200 for a single plug plus installation.
If multiple glow plugs show wear or the entire set needs replacement, budget $250 to $600 for the full set and associated labor.

Overall, fixing P067D usually falls in the $80 to $600 range. Proper diagnosis before purchasing parts saves money—the worst-case scenario is rarely the first thing to check.

Can You Drive with P067D?

Once the engine reaches operating temperature, driving remains safe. The primary concern is cold-weather starting: with one or more glow plugs inoperative, the engine may fail to start on cold mornings or crank sluggishly. If you live in a cold climate, prioritize this repair before winter arrives. In mild weather, you can postpone the fix temporarily but monitor starting performance closely.