Engine Oil Temperature Sensor Out of Self-Test Range
The P1184 code indicates that the Engine Oil Temperature (EOT) sensor is reporting a value outside the expected self-test range during the key-on engine-off (KOEO) or key-on engine-running (KOER) self-test. This typically means the sensor is either shorted, open, or reading an implausible temperature (e.g., extremely high or low). The PCM monitors the EOT sensor for rationality; if the voltage is too high (indicating cold) or too low (indicating hot) beyond normal limits, this code sets. Common causes include a faulty EOT sensor, wiring issues (shorts, opens, corrosion), or a contaminated sensor connector.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine may run poorly or have reduced performance
- Possible hard starting or stalling
- Inaccurate oil temperature reading on gauge (if equipped)
2. Most Common Causes
- Open circuit in the sensor or component wiring
- Corroded, damaged, or disconnected electrical connector
- Internally damaged specific component (e.g., O2 sensor, relay, or valve)
- Blown fuse in the corresponding circuit
- Internal failure in the engine control module (ECM)
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data. Record the EOT sensor value.
Step 2: Visually inspect the EOT sensor and its connector for damage, corrosion, or loose pins.
Step 3: Disconnect the EOT sensor and measure its resistance with a multimeter. Compare to manufacturer specifications (typically 100k-1M ohms at cold, dropping to ~100 ohms hot).
Step 4: Check the sensor signal wire for shorts to ground or power, and for open circuits. Repair as needed.
Step 5: If sensor and wiring are good, replace the EOT sensor and clear codes. Test drive to verify repair.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally not recommended to drive long distances with this code, as inaccurate oil temperature readings can lead to engine damage if the oil is actually overheating or if the PCM uses incorrect temperature data for fueling and timing.
How much does it cost to fix?▼
The cost to fix P1184 typically ranges from $50 to $150, including parts (EOT sensor $20-$60) and labor (0.5-1 hour). Diagnostic fees may add $50-$100.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.