AutoCodes – Generic – P11C8

P11C8 Code - NOx Sensor 2 Heater Ground Circuit High

Quick Answer

The Nitrogen Oxides (NOx) sensors are part of the selective catalytic reduction system, a device used to reduce NOx emission on diesel engines. Common causes include Faulty Nitrogen Oxides (NOx) Sensor 2, Nitrogen Oxides Sensor 2 harness is open or shorted, Nitrogen Oxides Sensor 2 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: P11C8 indicates NOx Sensor 2 Heater Ground Circuit High.
Common causes: Common causes include Faulty Nitrogen Oxides (NOx) Sensor 2, Nitrogen Oxides Sensor 2 harness is open or shorted, Nitrogen Oxides Sensor 2 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.

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Code Popularity 2,208

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 24, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P11C8 Description

The Nitrogen Oxides (NOx) sensors are part of the selective catalytic reduction system, a device used to reduce NOx emission on diesel engines. There are two NOx sensors, one placed upstream of selective catalytic reduction, to measure inlet NOx concentration, and one placed downstream. They are connected with the control module via CAN and all the information is exchanged through it. Since it is a smart sensor, all the electrical monitoring is performed inside the sensor and only the results are sent to the Engine Control Module (ECM). 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 the 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 (reductant) added by varying the reductant injector duty cycle in response to changes in engine exhaust 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. The Diagnostic Trouble Code (DTC) will be set if the ECM software detects a fault in the NOx sensor circuitry or a performance fault in the NOx sensor for greater than 2 s.

OBDII Code P11C8 - NOx Sensor 2 Heater Ground Circuit High - AutoCodes.com — P11C8 Code - NOx Sensor 2 Heater Ground Circuit High

What does this mean?

What are the Possible Causes of the DTC P11C8?

Faulty Nitrogen Oxides (NOx) Sensor 2
Nitrogen Oxides Sensor 2 harness is open or shorted
Nitrogen Oxides Sensor 2 circuit poor electrical connection

How to Fix the DTC P11C8?

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 P11C8 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 P11C8 code?

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Information for Specific Makes

P11C8 BMW — Pedal Position Sensor Substitute Operation
P11C8 Buick — NOx Sensor 2 Heater Ground Circuit High
P11C8 Cadillac — NOx Sensor 2 Heater Ground Circuit High
P11C8 Chevrolet — NOx Sensor 2 Heater Ground Circuit High
P11C8 GMC — NOx Sensor 2 Heater Ground Circuit High
P11C8 MINI — Pedal Position Sensor Substitute Operation

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P11C8 Code

1. What are the common symptoms of OBDII code P11C8 (NOx Sensor 2 Heater Ground Circuit High)?

- Common symptoms include the malfunction indicator light (MIL) or check engine light coming on, reduced engine performance, and potential failure to pass emissions testing.

2. What can cause the OBDII code P11C8 (NOx Sensor 2 Heater Ground Circuit High) to trigger?

- Possible causes include a faulty NOx sensor, damaged wiring or connectors in the sensor circuit, or a problem with the engine control module (ECM).

3. How serious is the OBDII code P11C8 (NOx Sensor 2 Heater Ground Circuit High)?

- While not an immediate threat to vehicle safety, ignoring this code can lead to increased emissions, reduced fuel efficiency, and potential damage to other engine components over time.

4. Can I continue driving my vehicle with the OBDII code P11C8 (NOx Sensor 2 Heater Ground Circuit High) present?

- It is generally safe to drive the vehicle for a short period with this code, but it is recommended to have the issue diagnosed and repaired as soon as possible to prevent further problems.

5. How can I diagnose the OBDII code P11C8 (NOx Sensor 2 Heater Ground Circuit High) at home?

- Diagnosing this code usually requires a professional OBDII scanner to read the fault codes, followed by a thorough inspection of the NOx sensor, wiring, and related components for any visible damage or issues.

6. Is it possible to repair the OBDII code P11C8 (NOx Sensor 2 Heater Ground Circuit High) myself?

- While some DIY enthusiasts may attempt to replace a faulty NOx sensor or repair damaged wiring, it is recommended to consult a qualified mechanic for accurate diagnosis and repair of this issue.

7. How much does it typically cost to fix the OBDII code P11C8 (NOx Sensor 2 Heater Ground Circuit High)?

- The cost of repairing this code can vary depending on the underlying cause, but it may range from $200 to $500 for parts and labor at a professional auto repair shop.

8. Can a faulty NOx sensor cause other problems in the vehicle besides triggering the P11C8 code?

- Yes, a faulty NOx sensor can lead to reduced fuel efficiency, increased emissions, and potential damage to the catalytic converter if left unresolved for an extended period.

9. Will resetting the error codes using an OBDII scanner make the P11C8 (NOx Sensor 2 Heater Ground Circuit High) code disappear permanently?

- Resetting the error codes may temporarily clear the MIL, but if the underlying issue causing the P11C8 code is not fixed, the code is likely to reappear after some driving cycles.

10. How long does it take to repair the OBDII code P11C8 (NOx Sensor 2 Heater Ground Circuit High)?

- The repair time can vary based on the specific cause of the code and the availability of parts, but most repairs related to this code can be completed within a few hours to a day at a professional repair facility.