A common issue that Nissan owners experience is the P1148 code appearing frequently. It will be indicated if there is an issue with the air-fuel ratio. The engine efficiency can be improved by utilizing the air-fuel ratio and oxygen sensors while reducing emissions.
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What is the meaning of the P1148 Code?
PCM detects the P1148 code due to a closed-loop control issue with Bank 1 air/fuel ratio sensor.
Bank 1 is the term used to denote the engine side that corresponds to the cylinder number. The term “closed loop” refers to the process by which the PCM utilizes input from a sensor.
The purpose of the heater elements in air/fuel ratio sensors is to heat them up to 1380°F (750°C).
To maintain the sensors’ operation within a specific temperature range, pulse modulation is utilized to accurately control their temperature, while a dedicated circuit controls the heater element. An air/fuel sensor’s efficiency depends on the temperature at which it operates.
Several sensors can connect with the PCM/ECM of your car. By using sensor data, it can control various engine functions. The powertrain control module (PCM) detects a DTC P1148 when there is a lack of adequate air/fuel ratio sensor data from Bank 1.
P1148 Code Common Case
- Exhaust Leak: An exhaust leak is located near the A/F ratio sensor.
- Sensors can get contaminated by oil, carbon, or silicone in additives.
- A resistor that has been poorly tuned is causing problems with the sensor connector.
- Wiring harness: Check the wiring Damage, short, or harness.
- Air/fuel Ratio Sensor: The ratio sensors that detect air and fuel are faulty and do not provide accurate readings. The air/fuel ratio is contaminated and needs to be cleaned or replaced.
- Oxygen Sensor: The heated oxygen sensor on bank 1 has malfunctioned and needs to be fixed.
- ECM/PCM: Your next step is to clear the code and then test drive your vehicle to check if the issue persists. If the sensor or engine control module fails, replacing one or both of them may be necessary.
What Symptoms of DTC P1148 Nissan
- High fuel consumption
- Lower engine performance.
- Check Engine Light on(Service Soon Light On)
- Unstable idling, Rough idling
- Engine hesitates during acceleration or speed-up.
- A problem with the Vehicle starting.
- Idling speed can exceed or fall below acceptable limits.
How to Fix P1148 Code
To resolve the P1148 Nissan code, certain diagnostic steps must be taken, such as:
- Scan the ECM through the Scanning Tool to collect codes and freeze frame data.
- Erase the codes and go for a test drive to check if they reappear.
- Examine the wiring harness and connectors for damage or corrosion.
- Examine the A/F sensor or HO2S sensor circuit’s voltage and resistance.
- In case of a faulty or out-of-specification A/F sensor or HO2S sensor, replace it.
- Look for exhaust leaks and repair them if necessary.
- Check the sensor’s fuse and replace it if it’s blown.
- Check the ECM and replace it if needed.
