P066D 2018 Chevrolet Silverado Code - Cylinder 2 Glow Plug Control Circuit High Voltage
Quick Answer
n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #2 glow plug, Cylinder #2 glow plug harness is open or shorted, Cylinder #2 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
- P066D 2018 Chevrolet Silverado indicates Cylinder 2 Glow Plug Control Circuit High Voltage.
- Common causes
- Common causes include Faulty cylinder #2 glow plug, Cylinder #2 glow plug harness is open or shorted, Cylinder #2 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 P066D 2018 Chevrolet Silverado 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 P066D 2018 Chevrolet Silverado?
- Faulty cylinder #2 glow plug
- Cylinder #2 glow plug harness is open or shorted
- Cylinder #2 glow plug circuit poor electrical connection
- Faulty Glow Plug Control Module
How to Fix the DTC P066D 2018 Chevrolet Silverado?
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 P066D 2018 Chevrolet Silverado 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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Frequently Asked Questions about P066D 2018 Chevrolet Silverado Code
1. What does the OBDII code P066D mean on a 2018 Chevrolet Silverado?
P066D indicates a "Cylinder 2 Glow Plug Control Circuit High Voltage," which means the glow plug circuit for cylinder 2 is experiencing a voltage level higher than expected.
2. What are the common symptoms of code P066D in a 2018 Silverado?
Symptoms may include difficulty starting the engine in cold conditions, reduced engine performance, an illuminated check engine light, and possibly rough idling.
3. What causes the P066D code to appear in a 2018 Chevrolet Silverado?
Common causes include a faulty glow plug, damaged glow plug control module, wiring issues like corrosion or shorts, or a malfunctioning PCM (powertrain control module).
4. Can I still drive my 2018 Silverado with the P066D code active?
While the truck may still run, driving with this code is not recommended, especially in cold weather, as it could lead to starting issues or further damage to the engine.
5. How do I diagnose the P066D code on a 2018 Silverado?
Start by inspecting the glow plug and wiring for cylinder 2 for signs of damage. Test the glow plug's resistance and check for proper voltage at the glow plug connector using a multimeter.
6. How can I fix the P066D code on my 2018 Chevrolet Silverado?
Repairs may include replacing the faulty glow plug, repairing damaged wiring or connectors, replacing the glow plug control module, or reprogramming/updating the PCM if necessary.
7. How much does it cost to fix a P066D code on a 2018 Silverado?
Costs can vary, but replacing a glow plug typically ranges from $100 to $300, while replacing the glow plug control module or repairing wiring may cost more depending on labor rates and parts availability.
8. Can a bad glow plug cause the P066D code on a 2018 Chevrolet Silverado?
Yes, a bad or failing glow plug in cylinder 2 is a common cause of the P066D code.
9. Will clearing the P066D code fix the issue on my 2018 Silverado?
Clearing the code will turn off the check engine light temporarily, but if the underlying issue isn’t resolved, the code will likely return.
10. Does the P066D code affect emissions in a 2018 Silverado?
Indirectly, yes. A malfunctioning glow plug can lead to incomplete combustion, which may increase emissions over time.
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