P066C Code - Cylinder 2 Glow Plug Control Circuit Low 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
- P066C indicates Cylinder 2 Glow Plug Control Circuit Low 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 P066C 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 P066C?
- 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 P066C?
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 P066C 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.
Need more information about the P066C code?
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Need Help with the Code?
Get the P066C code diagnosed by a professional: Find a repair shop in your area
Information for Specific Makes
- P066C Chevrolet — Cylinder 2 Glow Plug Control Circuit Low Voltage
- P066C Ford — Cylinder 2 Glow Plug Control Circuit Low
- P066C GMC — Cylinder 2 Glow Plug Control Circuit Low Voltage
Frequently Asked Questions about P066C Code
1. What are the common symptoms of OBDII code P066C (Cylinder 2 Glow Plug Control Circuit Low Voltage)?
Common symptoms include difficulty starting the engine, rough idling, decreased fuel efficiency, and the illumination of the check engine light.
2. What are the possible causes of OBDII code P066C?
Possible causes may include a faulty glow plug, damaged wiring or connectors in the glow plug circuit, a defective glow plug control module, or a problem with the engine control module.
3. How can I diagnose the issue related to OBDII code P066C?
To diagnose the issue, you can use a diagnostic scanner to retrieve the trouble codes, inspect the glow plug and its connections, check the voltage in the circuit, and perform a continuity test on the wiring.
4. Can I continue driving with OBDII code P066C present?
It is not recommended to continue driving with this code present, as it can lead to poor engine performance, potential damage to other components, and increased emissions. It's best to address the issue promptly.
5. How can I repair OBDII code P066C?
Repair options may include replacing the faulty glow plug, repairing or replacing damaged wiring or connectors, replacing the glow plug control module, or reprogramming the engine control module if needed.
6. Is it necessary to clear the OBDII code P066C after making repairs?
Yes, it is important to clear the code using a diagnostic scanner after making repairs. This will reset the check engine light and allow you to monitor if the issue has been successfully resolved.
7. Are there any preventative maintenance tips to avoid OBDII code P066C in the future?
To prevent this code from reoccurring, it is recommended to follow the manufacturer's recommended maintenance schedule, regularly inspect the glow plug system, and address any issues promptly.
8. Can a DIY enthusiast fix OBDII code P066C at home?
Depending on your level of experience and access to tools, some DIY enthusiasts may be able to address OBDII code P066C at home. However, if you are unsure or lack the necessary expertise, it's best to consult a professional mechanic.
9. Will OBDII code P066C affect vehicle safety?
While OBDII code P066C is more related to engine performance and emissions, unresolved issues can indirectly impact vehicle safety if left unaddressed. It's best to resolve the problem to maintain overall vehicle health.
10. How long does it typically take to repair OBDII code P066C?
The repair time for OBDII code P066C can vary depending on the specific cause of the issue, availability of parts, and the expertise of the person performing the repair. In general, it may take a few hours to a full day to complete the repair.
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