P1186 (Volkswagen, Audi, Skoda, Seat) Linear lambda probe, common ground, short circuit to positive
Content
P1186 – OBD-II Trouble Code Technical Description
Trouble code P1186 indicates a problem with the linear oxygen sensor, namely a short circuit to positive in the common ground circuit in Volkswagen, Audi, Skoda, Seat vehicles.
What does the fault code mean P1186?
Trouble code P1186 indicates a problem with the linear oxygen sensor, which is part of the exhaust gas control system. In this case, the code indicates a short circuit to positive in the common ground circuit, which means that the common ground circuit of the linear oxygen sensor is shorted to positive. This leads to abnormal operation of the sensor, since it cannot correctly transmit a signal about the oxygen content in the exhaust gases. When the linear oxygen sensor reports incorrect data to the engine control module, it can result in inefficient combustion of fuel in the engine cylinders.
Possible reasons
Possible reasons for DTC P1186:
- Damaged wiring or connectors: Damaged or broken wires, or oxidation or corrosion in connectors can cause a short to positive.
- Defective linear oxygen sensor: If the sensor is damaged or faulty, it may cause a short circuit to positive.
- Problems with the engine control unit (ECU): A malfunction in the engine control unit can cause the linear oxygen sensor to malfunction, including a short circuit to positive.
- Mechanical damage: Physical damage to the linear oxygen sensor or its cable may cause a short circuit.
- Car grounding problems: Faults in the vehicle's grounding system can cause a short circuit to positive.
- Electrical noise or overload: Uncontrolled electrical signals or electrical circuit overloads can also cause a short circuit.
To accurately determine the cause, it is recommended to carry out a comprehensive diagnosis using a diagnostic scanner and checking the wiring and oxygen sensor.
What are the symptoms of a fault code? P1186?
Symptoms for a P1186 trouble code may vary depending on the specific conditions and characteristics of the vehicle, some of the possible symptoms are:
- Increased fuel consumption: A short to positive in the common ground circuit of the linear oxygen sensor may result in an incorrect signal about the oxygen content in the exhaust gases. This can lead to an incorrect mixture of fuel and air, which in turn can increase the vehicle's fuel consumption.
- Loss of engine power: Incorrect operation of the linear oxygen sensor can affect combustion efficiency, which may result in loss of engine power and poor overall engine performance.
- Unstable idle: If there is a short circuit to positive in the linear oxygen sensor, the engine may operate unstably at idle.
- Unstable engine operation: You may experience shaking, jerking, or other unusual sounds or vibrations when the engine is running.
- Check Engine light appears and/or flashes: Trouble code P1186 will activate the Check Engine light on the vehicle's dashboard.
How to diagnose a fault code P1186?
The following steps are recommended to diagnose DTC P1186:
- Check the error code: Use a scan tool to read the P1186 fault code from the Engine Control Module memory.
- Check wiring and connectors: Inspect the wiring and connectors connecting the linear oxygen sensor to the engine control module for damage, breaks or corrosion. Also check the condition of grounding and connections.
- Check Linear Oxygen Sensor: Use a multimeter to check the resistance of the oxygen sensor and make sure it meets the manufacturer's specifications.
- Diagnostics of the engine control unit (ECU): Check the operation of the engine control unit for possible malfunctions that could lead to a short circuit to positive in the common ground circuit.
- Grounding system testing: Check the vehicle's grounding system for proper operation and no damage.
- Test in real time: Use a diagnostic scan tool to monitor real-time data to evaluate the performance of the linear oxygen sensor and other engine management system components while the engine is running.
If you are unsure of these procedures, it is recommended that you contact a qualified auto mechanic or service center for further diagnosis and repair.
Diagnostic errors
When diagnosing DTC P1186, the following errors may occur:
- Faulty wiring or connectors not detected: If wiring and connectors are incompletely or incorrectly checked, the actual cause of a short to positive may be missed.
- Incorrect interpretation of oxygen sensor dataNote: Interpreting oxygen sensor data requires experience and diagnostic knowledge. Misreading or misinterpreting the data may lead to the problem being incorrectly identified.
- Faulty linear oxygen sensor: In the absence of additional diagnostics and testing, the assumption may be erroneously made that the linear oxygen sensor is faulty, when in fact the problem may be in the wiring, connectors or engine control unit.
- Ignoring other potential causes: Failure to consider and check other engine management system components, such as the engine control unit (ECU) or grounding system, may result in an incorrect diagnosis.
- Wrong solution to the problem: Deciding to replace a component without proper diagnosis and inspection may result in unnecessary repair costs.
To prevent these errors, it is important to carry out a complete and systematic diagnosis using the correct equipment and techniques.
How serious is the fault code? P1186?
Trouble code P1186 is serious because it indicates a problem with the linear oxygen sensor and a short circuit to positive in the common ground circuit. This sensor plays a key role in monitoring the oxygen content of the exhaust gases and in the correct operation of the engine management system.
Incorrect operation of the linear oxygen sensor can lead to inefficient fuel combustion, loss of engine power, increased fuel consumption, as well as increased emissions of harmful substances into the atmosphere. Moreover, it can affect the overall performance and longevity of the engine.
Therefore, when trouble code P1186 appears, it is recommended to immediately begin diagnosis and repair in order to prevent possible negative consequences for engine operation and environmental safety.
What repair will help eliminate the code? P1186?
Resolving trouble code P1186 requires systematic diagnosis and, depending on the problem found, may require the following:
- Checking wiring and connectors: The first step is to check the wiring and connectors connecting the linear oxygen sensor to the engine control module. Replace or repair damaged wires or connectors as necessary.
- Replacing a linear oxygen sensor: If the oxygen sensor is found to be faulty, it must be replaced with a new one that meets the original manufacturer specifications.
- Checking the engine control unit (ECU): If you suspect a faulty engine control unit, perform additional checks and, if necessary, replace or reprogram the ECU.
- Checking the grounding system: Make sure the vehicle's grounding system is working properly, and if necessary, carry out additional checks and restore the grounding.
- Clearing errors and re-diagnosis: After performing repairs and replacing components, use a diagnostic scan tool to clear DTC P1186 from the ECU memory. After this, retest the system to ensure that it is working properly and there are no further problems.
Repairs and resolution of the P1186 code should be performed by a qualified auto mechanic or an authorized service center, especially if component replacement or intervention to the vehicle's electrical system is required.
