P067E — Cylinder 6 Glow Plug Control Circuit Low

Will P067E clear itself?

Sometimes P067E 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 does OBD2 code P067E mean?

OBD2 code P067E flags a problem with the diesel glow plug system (cylinder 6 glow plug control circuit low). The car is usually drivable while you plan the repair. Common culprits: faulty glow plug relay or control module, burned-out glow plug, corroded glow plug connectors.

What are the symptoms of P067E?

Drivers most often notice: hard starting in cold weather, rough idle until warmed up, glow plug warning light staying on, Check Engine Light on.

What is the most common cause of P067E?

The most common causes are: faulty glow plug relay or control module, burned-out glow plug, corroded glow plug connectors.

How do I diagnose P067E myself?

Start with a scan: confirm P067E, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the cylinder 6 glow plug control, and verify the suspect component against live data before buying parts.

On a cold morning, diesel engines need help getting combustion started, and that's the job of the glow plug system. When the powertrain control module stores trouble code P067E, it's telling you that cylinder 6's glow plug circuit has dropped below the acceptable voltage threshold — essentially reading "low." The module logs this code after running multiple verification checks, and it pairs the fault with a freeze frame snapshot capturing engine speed, load, coolant temperature, and vehicle speed at the moment the problem occurred. Understanding what P067E means requires knowing how the glow plug control system works: the engine computer energizes the glow plugs through a dedicated control circuit, and when something prevents proper voltage from reaching cylinder 6's plug, the low circuit condition triggers the code.

The glow plug control circuit on cylinder 6 carries a signal from the engine control unit to the actual plug sitting inside the combustion chamber. During startup, the module activates each glow plug for a few seconds to heat the cylinder and help ignite the fuel-air mixture. If the voltage on this specific circuit stays too close to ground instead of reaching the expected operating level, the control module marks the reading as out-of-specification and sets P067E. The root cause could be a short to ground somewhere in the wiring, a failed component pulling the signal low, or simply a broken connection starving the circuit of power. Whatever the underlying issue, the computer needs to see the fault confirmed across multiple drive cycles before it permanently stores the code and illuminates the check engine light.

Cylinder numbering follows different conventions depending on engine orientation. On inline engines, cylinder 6 sits at the flywheel end of the block. On V-type engines, the count starts differently depending on the manufacturer — checking the firing order diagram for your specific application prevents misdiagnosis and wasted time. Accessing cylinder 6 may also involve removing surrounding components, which directly affects labor costs when it comes time to repair the problem.

Common Symptoms of P067E

• Engine cranks slowly or fails to start when temperatures drop below freezing
• Rough running and noticeable vibration at idle until the engine reaches normal operating temperature
• Glow plug indicator lamp remains illuminated after the normal pre-heat cycle completes
• Check engine light stays on continuously
• White or grayish exhaust smoke visible from the tailpipe during cold starts, indicating unburned fuel passing through a cylinder that cannot ignite properly
• Reduced overall engine performance in colder conditions until all cylinders warm up

Most Likely Causes of P067E

The most frequent culprits behind this trouble code involve power delivery problems rather than the glow plug itself:

• Supply voltage missing from the cylinder 6 glow plug circuit due to a blown fuse or relay failure
• Signal wire for cylinder 6 grounded out by chafed insulation rubbing against metal edges or bracket corners
• Glow plug relay or control module malfunctioning and failing to send activation voltage to the cylinder 6 circuit
• Corrosion buildup inside the cylinder 6 glow plug electrical connector, creating high resistance
• Physical damage to the wiring harness in the glow plug circuit, including broken strands or melted insulation from heat exposure
• Cylinder 6 glow plug internally shorted and pulling the control circuit to ground
• The glow plug itself burned out and creating an open circuit that the module interprets as abnormal

How to Diagnose P067E

Start by connecting a scan tool and confirming that P067E is stored in the powertrain control module. Before clearing anything, record the freeze frame data — this shows engine speed, load percentage, coolant temperature, and vehicle speed at the exact moment the fault triggered, which helps you recreate those conditions during the verification drive.

Next, pull all stored and pending diagnostic trouble codes from the module. Codes in other categories often point to the actual root cause rather than just the symptom. While you are at it, search for any technical service bulletins or factory campaigns that apply to your specific vehicle — manufacturers sometimes release software updates or harness modifications that address known glow plug circuit failures.

Perform a thorough visual inspection of the engine wiring harness routed near the cylinder 6 glow plug. Look for cracked insulation, wire strands visible through the jacket, melted plastic from heat damage, and any signs that the harness has been rubbing against brackets or the exhaust manifold. Pull the cylinder 6 glow plug connector apart and examine the terminals for corrosion, bent pins, or moisture intrusion.

Measure voltage at the cylinder 6 glow plug connector while the key is in the on position but before the engine starts. If no voltage is present, trace the circuit back to the relay or module. Then check resistance from the signal wire to a known good ground — a reading of near-zero ohms confirms a short-to-ground condition in the harness that needs repair.

Test each glow plug individually by measuring resistance across its terminals. A properly functioning plug reads between one and six ohms depending on the design. Infinite resistance means an open filament and a failed plug. Finally, clear the code, complete a full drive cycle that recreates the freeze frame conditions, and verify that P067E does not return before calling the diagnosis complete.

Repair Options and Costs for P067E

Address the least expensive likely causes before committing to major component replacement. If inspection reveals a single faulty glow plug, that component replacement typically runs $80 to $200 including parts and labor. When the glow plug relay or control module is confirmed as the source, expect to pay between $150 and $450 for the replacement part plus installation time. If multiple cylinders show wear or the harness requires substantial repair, replacing the complete glow plug set costs roughly $250 to $600 depending on the engine and parts sourcing.

Total Repair Cost for P067E

The actual out-of-pocket expense hinges entirely on which component triggered the low circuit condition. Based on typical independent shop labor rates in the