P1427 EGI Temperature Sensor Circuit Malfunction
The P1427 code indicates a fault in the EGI (Electronic Gasoline Injection) temperature sensor circuit, commonly found in Nissan and Infiniti vehicles. Depending on the model and year, this sensor may refer to the engine control module (ECM) temperature sensor or the intake air temperature (IAT) sensor integrated into the mass airflow (MAF) meter. The ECM detects a voltage signal outside the expected range—such as an open circuit, short to ground, or short to positive—preventing proper air-fuel mixture compensation and emission control.
01. Most Common Causes
- Faulty EGI/IAT sensor (internal open or short circuit)
- Damaged, corroded, or loose wiring or connectors in the sensor circuit
- Short to ground or to reference voltage (5V) in the wiring harness
- Internal ECM failure in the sensor reading circuit
- Poor connection at the MAF meter connector if the IAT sensor is integrated
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor engine performance or rough idle
- Increased fuel consumption
- Failed emissions test
03. Step-by-Step Diagnosis
Scan for codes and verify P1427 is present
Visually inspect the EGI/IAT sensor connector and wiring for damage or corrosion
Measure sensor resistance and compare to manufacturer specifications
Check for 5V reference voltage and ground at the sensor connector
Test the wiring harness for shorts or opens between the sensor and ECM
If all else passes, suspect an internal ECM fault
1. Frequently Asked Questions
Is it safe to drive?▼
The vehicle may still be drivable, but performance and fuel economy will likely suffer. It is recommended to diagnose and repair the issue promptly to avoid further damage or failed emissions.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the sensor, wiring, or ECM needs replacement. Labor and parts vary by vehicle model and shop rates.