P06CC — Cylinder 8 Glow Plug Incorrect

OBD2 code P06CC flags a problem with the diesel glow plug system (cylinder 8 glow plug incorrect). The car is usually drivable while you plan the repair. Common culprits: faulty glow plug relay or control module, blown fuse in the glow plug circuit, burned-out glow plug.

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 P06CC 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 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 P06CC does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P06CC (parts and labor, USD, independent shop rates): Replace a full set of glow plugs: $250–$600; Replace the glow plug relay/module: $150–$450; Replace one glow plug: $80–$200. Overall, fixing P06CC 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

How much does it cost to fix P06CC?

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

Will P06CC clear itself?

Sometimes P06CC clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What is the most common cause of P06CC?

The most common causes are: faulty glow plug relay or control module, blown fuse in the glow plug circuit, burned-out glow plug.

What does OBD2 code P06CC mean?

What are the symptoms of P06CC?

Drivers most often notice: Check Engine Light on, glow plug warning light staying on, white smoke after a cold start, hard starting in cold weather.

When your vehicle's computer detects that cylinder 8's glow plug isn't operating within factory specifications, it logs trouble code P06CC. This diagnostic code specifically indicates an electrical malfunction or performance problem with the glow plug responsible for that cylinder in a diesel engine. The powertrain control module constantly monitors the resistance and voltage readings of each glow plug, and when the data from cylinder 8 deviates from expected parameters, P06CC gets stored and the check engine light illuminates.

Diesel engines rely on glow plugs to heat the combustion chamber during startup, particularly in colder conditions where fuel struggles to ignite. Each cylinder contains its own glow plug, and cylinder 8 sits at the end of the firing sequence in most inline configurations. When the ECM detects that cylinder 8's glow plug is drawing too much current, showing infinite resistance from a burned-out element, or failing to heat properly, it sets P06CC after multiple drive cycles to confirm the fault isn't transient. Freeze frame data captured alongside P06CC records the exact engine speed, load, temperature, and vehicle speed at the moment the problem occurred, giving you a precise starting point for troubleshooting.

Common Symptoms of P06CC

The check engine light or dedicated glow plug warning lamp stays illuminated
Visible white smoke billowing from the exhaust pipe during cold starts
Difficulty cranking the engine, especially on frigid mornings
Rough and uneven idle that stabilizes once the engine reaches normal operating temperature
Decreased fuel economy as the engine compensates for incomplete combustion in cylinder 8

What Causes P06CC?

Corroded or moisture-damaged electrical connectors at the glow plug harness — the most frequent culprit
A defective glow plug control relay or integrated control module that fails to activate the heating cycle
A blown fuse protecting the glow plug circuit from overload
Chafed, melted, or rodent-damaged wiring insulation in the glow plug wiring harness
A completely burned-out glow plug element with infinite electrical resistance
Poor ground connection at the glow plug mounting point

How to Diagnose P06CC

Hook up an OBD2 scanner and verify that P06CC is the active or stored code, then record the freeze frame data — this snapshot tells you exactly what the engine was doing when the fault triggered.
Scan for any additional trouble codes that might point to the underlying cause, such as voltage supply issues or communication faults. Cross-reference any findings against manufacturer technical service bulletins for your specific make and model.
Perform a thorough visual inspection of the glow plug wiring harness and connectors for cylinder 8, looking for broken wires, corroded pins, loose debris, or signs of heat damage.
Use a multimeter to check the resistance of each glow plug individually — a functioning plug reads between 0.5 and 2 ohms, while an open circuit reads infinity and confirms failure.
Verify that battery voltage reaches the glow plug rail during the pre-glow sequence using a test light or voltmeter.
Clear P06CC from the ECU, then drive the vehicle through a complete drive cycle that mirrors the conditions stored in the freeze frame data, and confirm the code does not reappear.

How to Fix P06CC

Address the simplest and most common failures before committing to expensive component replacements. Replacing a single failed glow plug typically runs $80–$200, including parts and labor. If the glow plug control relay or module is at fault, expect to pay $150–$450 for the replacement part and installation. Swapping out an entire set of glow plugs — which many technicians recommend doing proactively when one fails — costs between $250–$600 depending on your vehicle and labor rates.

The total repair cost for P06CC usually falls somewhere between $80 and $600. An accurate diagnosis before purchasing parts is essential, because the priciest scenario is rarely the first one to investigate. Spending time at the beginning confirming whether the problem is a simple corroded connector or a failed relay can save you hundreds of dollars in unnecessary parts purchases.

Can You Drive with P06CC?

Once the engine is running and fully warmed up, a vehicle with P06CC stored is generally safe to operate under normal conditions. The primary concern is cold-weather starting: with cylinder 8's glow plug non-functional, you may experience hard cranking or a complete failure to start on cold mornings. If you live in a cold climate or regularly park outdoors in winter conditions, repair this code before temperatures drop. Driving with a faulty glow plug in freezing weather risks leaving you stranded and can allow unburned fuel to dilute your engine oil, causing long-term damage.