P068E Code - Cylinder 8 Glow Plug Control Circuit Low Voltage
Quick Answer
n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #8 glow plug, Cylinder #8 glow plug harness is open or shorted, Cylinder #8 glow plug circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P068E indicates Cylinder 8 Glow Plug Control Circuit Low Voltage.
- Common causes
- Common causes include Faulty cylinder #8 glow plug, Cylinder #8 glow plug harness is open or shorted, Cylinder #8 glow plug circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P068E Description
Control of the glow plugs is accomplished by the Glow Plug Control Module. The nominal voltage for the glow plugs is 5.4 volts. When the ignition is turned On, the Glow Plug Control Module applies 7.2 V for 2.2 s, then 5.7 V for 0.8 s, and then 5.4 V until 1200°C (2192°F) is reached. The maximum voltage of the system is 10 V. While the engine is running the voltage will vary between 4.7 - 10 V when in closed loop control to maintain a glow plug temperature that ranges from 1150° - 1180°C (2102° - 2156°F). The temperature and the power consumption are controlled between the Engine Control Module (ECM) and the Glow Plug Control Module within a wide range to suit the engine's pre-heating requirements. Each glow plug is energized individually. This capability yields more optimum heat times for the glow plugs, thus pre - glow times can be kept to a minimum for a short wait to crank times and maximum glow plug durability.
What are the Possible Causes of the DTC P068E?
- Faulty cylinder #8 glow plug
- Cylinder #8 glow plug harness is open or shorted
- Cylinder #8 glow plug circuit poor electrical connection
- Faulty Glow Plug Control Module
How to Fix the DTC P068E?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P068E code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Makes
- P068E Chevrolet — Cylinder 8 Glow Plug Control Circuit Low Voltage
- P068E Ford — Cylinder 8 Glow Plug Control Circuit Low
- P068E GMC — Cylinder 8 Glow Plug Control Circuit Low Voltage
Frequently Asked Questions about P068E Code
What does the OBDII code P068E mean?
P068E indicates a low voltage issue in the glow plug control circuit for cylinder 8, often related to starting problems in diesel engines.
What are the common symptoms of code P068E?
Symptoms may include difficulty starting the engine, rough idling, poor acceleration, and an illuminated check engine light.
What causes the P068E code?
Common causes include a faulty glow plug, damaged wiring or connectors, a malfunctioning glow plug control module, or issues with the vehicle’s battery or alternator.
Can driving with code P068E damage my vehicle?
Driving with this code can lead to harder cold starts and increased engine wear, especially in colder climates, but it typically doesn’t cause immediate catastrophic damage.
How is code P068E diagnosed?
A mechanic will use a scan tool to confirm the code, inspect the glow plug and its control circuit, check for wiring issues, and test the battery and alternator for proper voltage.
Can I fix the P068E code myself?
If you’re comfortable working on your vehicle, you can check for damaged wiring or connectors and replace the glow plug. Otherwise, professional diagnosis is recommended.
How much does it cost to repair code P068E?
Repair costs can vary, but replacing a glow plug typically costs $50-$150. If the control module is faulty, repairs may range from $200-$500, depending on the vehicle.
What tools are needed to repair code P068E?
Basic tools like a multimeter for testing voltage, a scan tool for diagnosing the code, and appropriate wrenches or sockets for removing glow plugs are often required.
Can a weak battery trigger code P068E?
Yes, a weak or failing battery may not provide sufficient voltage to the glow plug system, potentially triggering this code.
How can I prevent code P068E from recurring?
Regularly inspect and maintain your glow plugs, control module, wiring, and battery to ensure proper operation and avoid low voltage issues.
Discuss the causes and fixes for P068E OBDII Code
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