P11D7 Code - Downstream NOx Sensor Self Diagnostic Bank 1 Sensor 2
Quick Answer
The reductant system uses two Nitrogen Oxide (NOx) sensors to monitor the amount of NOx in the engine's exhaust gas. Common causes include Faulty Nitrogen Oxide (NOx) Sensor, Nitrogen Oxide (NOx) Sensor harness is open or shorted, Nitrogen Oxide (NOx) Sensor 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
- P11D7 indicates Downstream NOx Sensor Self Diagnostic Bank 1 Sensor 2.
- Common causes
- Common causes include Faulty Nitrogen Oxide (NOx) Sensor, Nitrogen Oxide (NOx) Sensor harness is open or shorted, Nitrogen Oxide (NOx) Sensor 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 P11D7 Description
Each NOx sensor contains a sensing cell, a pumping cell, and a heater. A sample of exhaust gas passes through a diffusion gap between the sensing cell and the pumping cell. The NOx sensor maintains a constant reference voltage across the sensing cell. An electronic circuit within sensor controls the pump current through the pumping cell in order to maintain a constant voltage in the sensing cell. The amount of current required to maintain the reference voltage in the sensing cell is proportional to the concentration of NOx in the exhaust.
The ECM varies the amount of Diesel Exhaust Fluid (DEF) or reductant added by varying the reductant injector duty cycle in response to changes in engine exhaust out NOx levels.
The smart NOx sensors consist of two components, the NOx module and the NOx sensor element that are serviced as a unit. A circuit or performance condition with a NOx sensor is detected by the NOx sensor module. The smart NOx sensor module communicates the condition to the ECM over the serial data line. The ECM sets a DTC when a serial data message is received from the NOx sensor module.
What are the Possible Causes of the DTC P11D7?
- Faulty Nitrogen Oxide (NOx) Sensor
- Nitrogen Oxide (NOx) Sensor harness is open or shorted
- Nitrogen Oxide (NOx) Sensor circuit poor electrical connection
How to Fix the DTC P11D7?
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 P11D7 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
- P11D7 Chevrolet — Downstream NOx Sensor Self Diagnostic Bank 1 Sensor 2
- P11D7 GMC — Downstream NOx Sensor Self Diagnostic Bank 1 Sensor 2
Frequently Asked Questions about P11D7 Code
1. What are common symptoms of OBDII code P11D7?
- Common symptoms include decreased fuel efficiency, rough idling, and an illuminated check engine light.
2. What does OBDII code P11D7 indicate?
- OBDII code P11D7 indicates an issue with the Downstream NOx Sensor Self Diagnostic Bank 1 Sensor 2.
3. What are possible causes of OBDII code P11D7?
- Possible causes include a faulty downstream NOx sensor, wiring issues, or a problem with the engine control module.
4. How can I diagnose the cause of OBDII code P11D7?
- Diagnosing the issue may require using a diagnostic scanner to retrieve the specific error codes, conducting visual inspections of the sensor and wiring, and performing electrical tests.
5. Can I continue driving with OBDII code P11D7?
- It is not recommended to ignore OBDII code P11D7, as it can lead to further engine damage and potentially cause your vehicle to fail emissions tests.
6. How do I repair OBDII code P11D7?
- Repairing OBDII code P11D7 may involve replacing the downstream NOx sensor, repairing or replacing damaged wiring, or reprogramming the engine control module.
7. Are there any DIY tips for fixing OBDII code P11D7?
- While some may attempt to replace the downstream NOx sensor themselves, it is recommended to consult a professional mechanic for proper diagnosis and repair.
8. How much does it cost to fix OBDII code P11D7?
- The cost of fixing OBDII code P11D7 can vary depending on the exact cause of the issue, but it may range from $200 to $500 or more including parts and labor.
9. How long does it take to repair OBDII code P11D7?
- The repair time for OBDII code P11D7 can vary based on the extent of the issue and the availability of parts, but it typically takes a few hours to complete.
10. Can OBDII code P11D7 be prevented?
- While some causes of OBDII code P11D7 may be unavoidable, regular maintenance and prompt attention to any check engine lights can help prevent more severe issues.
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