P128A Code - Cylinder Head Temperature Sensor Circuit Intermittent/Erratic
Quick Answer
The Cylinder Head Temperature (CHT) Sensor is mounted into the wall of the cylinder head and is not connected to any coolant passages. Common causes include Wrong thermostat, Not at operating range, Engine overheated. 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
- P128A indicates Cylinder Head Temperature Sensor Circuit Intermittent/Erratic.
- Common causes
- Common causes include Wrong thermostat, Not at operating range, Engine overheated.
- 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 P128A Description
What are the Possible Causes of the DTC P128A?
- Wrong thermostat
- Not at operating range
- Engine overheated
- Low engine coolant level
- Faulty Cylinder Head Temperature (CHT) sensor
- Cylinder Head Temperature (CHT) sensor harness is open or shorted
- Cylinder Head Temperature (CHT) sensor circuit poor electrical connection
How to Fix the DTC P128A?
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 P128A 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
- P128A BMW — Nitrogen Oxide Sensor Regeneration Nitrogen Oxide Cat Regeneration Monitoring
- P128A Buick — Fuel Rail Pressure Sensor 1 Internal Performance
- P128A Cadillac — Fuel Rail Pressure Sensor 1 Internal Performance
- P128A Chevrolet — Fuel Rail Pressure Sensor 1 Internal Performance
- P128A Ford — Cylinder Head Temperature Sensor Circuit Intermittent/Erratic
- P128A GMC — Fuel Rail Pressure Sensor 1 Internal Performance
- P128A Lincoln — Cylinder Head Temperature Sensor Circuit Intermittent/Erratic
- P128A Mercury — Cylinder Head Temperature Sensor Circuit Intermittent/Erratic
- P128A MINI — Nitrogen Oxide Sensor Regeneration Nitrogen Oxide Cat Regeneration Monitoring
Frequently Asked Questions about P128A Code
1. What are common symptoms of OBDII code P128A?
- Common symptoms of code P128A include engine overheating, poor fuel efficiency, rough idling, and a noticeable decrease in engine performance.
2. What are the possible causes of OBDII code P128A?
- The code P128A is typically caused by a faulty cylinder head temperature sensor, wiring issues in the sensor circuit, or a problem with the engine control module (ECM).
3. How can I diagnose the OBDII code P128A?
- To diagnose code P128A, you can use an OBDII scanner to retrieve the code and check the cylinder head temperature sensor's readings. You may also need to inspect the sensor's wiring for any damage or corrosion.
4. Can I still drive my vehicle with the OBDII code P128A present?
- It is not recommended to drive your vehicle with the OBDII code P128A present, as it can lead to potential engine damage or overheating issues. It is best to address the underlying problem as soon as possible.
5. How do I repair OBDII code P128A?
- Repairing code P128A involves replacing the faulty cylinder head temperature sensor, repairing any damaged wiring in the sensor circuit, or addressing any ECM issues. It is recommended to consult a professional mechanic for proper diagnosis and repair.
6. Are there any DIY tips for fixing OBDII code P128A?
- If you have experience working on car electronics, you can try checking the sensor's wiring connections for any loose or corroded terminals. However, for a proper fix, it is advisable to seek help from a qualified technician.
7. Can a bad cylinder head temperature sensor cause other issues besides triggering OBDII code P128A?
- Yes, a faulty cylinder head temperature sensor can cause other issues such as incorrect temperature readings, which may lead to poor engine performance, overheating, and potential damage if not addressed promptly.
8. How much does it typically cost to repair OBDII code P128A?
- The cost of repairing OBDII code P128A can vary depending on the extent of the issue and the cost of parts and labor. It is recommended to get a few quotes from different mechanics to compare prices.
9. Will resetting the OBDII code P128A make it go away permanently?
- Resetting the OBDII code P128A may temporarily clear the code, but it will likely return if the underlying issue, such as a faulty sensor or wiring problem, is not addressed and repaired.
10. Is OBDII code P128A a serious issue that requires immediate attention?
- Yes, OBDII code P128A should be taken seriously and addressed promptly to prevent potential engine damage or overheating. It is best to have the issue diagnosed and repaired as soon as possible.
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