P066A Code - Cylinder 1 Glow Plug Control Circuit Low Voltage
Quick Answer
n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #1 glow plug, Cylinder #1 glow plug harness is open or shorted, Cylinder #1 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
- P066A indicates Cylinder 1 Glow Plug Control Circuit Low Voltage.
- Common causes
- Common causes include Faulty cylinder #1 glow plug, Cylinder #1 glow plug harness is open or shorted, Cylinder #1 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 P066A 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 P066A?
- Faulty cylinder #1 glow plug
- Cylinder #1 glow plug harness is open or shorted
- Cylinder #1 glow plug circuit poor electrical connection
- Faulty Glow Plug Control Module
How to Fix the DTC P066A?
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 P066A 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
- P066A Chevrolet — Cylinder 1 Glow Plug Control Circuit Low Voltage
- P066A Ford — Cylinder 1 Glow Plug Control Circuit Low
- P066A GMC — Cylinder 1 Glow Plug Control Circuit Low Voltage
Frequently Asked Questions about P066A Code
1. What are the common symptoms of OBDII code P066A (Cylinder 1 Glow Plug Control Circuit Low Voltage)?
- Common symptoms include hard starting, rough idling, decreased fuel efficiency, and illuminated check engine light.
2. What causes OBDII code P066A to trigger?
- This code is typically triggered by issues such as a faulty glow plug, damaged wiring in the glow plug circuit, or a malfunctioning glow plug control module.
3. How can I diagnose the Cylinder 1 Glow Plug Control Circuit Low Voltage issue?
- Diagnosis involves using a scan tool to read the OBDII code, testing the glow plug and related components for continuity and resistance, and inspecting the wiring for any damage.
4. Can I still drive my vehicle with OBDII code P066A present?
- It is not recommended to drive your vehicle with this code present, as it can lead to poor engine performance and potential damage if left unresolved.
5. What are the potential repair options for resolving OBDII code P066A?
- Repair options include replacing the faulty glow plug, repairing any damaged wiring, replacing the glow plug control module, or addressing any other underlying issues causing the low voltage condition.
6. How critical is it to address OBDII code P066A promptly?
- It is important to address this code promptly to prevent further issues with engine performance, fuel efficiency, and potential damage to other components in the vehicle.
7. Can weather conditions affect the glow plug performance and trigger OBDII code P066A?
- Yes, extreme cold weather conditions can impact the performance of glow plugs, leading to low voltage issues and triggering this OBDII code.
8. Is it possible for OBDII code P066A to be a false alarm?
- While it is possible for a sporadic fault to trigger this code temporarily, it is essential to thoroughly diagnose the issue to ensure it is not a recurring problem.
9. Are there any preventive maintenance tips to avoid OBDII code P066A in the future?
- Regularly inspecting and testing the glow plugs, wiring, and control module as part of routine maintenance can help prevent issues that lead to this code.
10. Can a DIY enthusiast repair OBDII code P066A themselves?
- Depending on the individual's skill level and access to tools, DIY enthusiasts may be able to address this code by following repair guides and procedures, but professional assistance is recommended for accurate diagnosis and repair.
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