Code
P1005
DACIA
P — Powertrain
Fuel temperature sensor - circuit malfunction
Views:
UK: 5
EN: 15
RU: 7
AI status
Completed
Completed
100%
Causes
- Damaged or corroded wiring/connector to the fuel temperature sensor
- Faulty fuel temperature sensor (open, shorted or out of spec)
- Poor ground or power supply to the sensor/ECM
- Water/contamination in connector or sensor
- Intermittent connector contact or wiring chafing
- ECM input circuit fault (rare)
Symptoms
- Malfunction indicator lamp (MIL) illuminated with P1005 stored
- Hard cold starting or longer cranking time
- Poor idle stability after cold start
- Reduced fuel economy or increased emissions
- ECM using default fuel temp value leading to drivability changes
- Freeze frame data showing abnormal fuel temp readings
What to check
- Read and record stored codes and freeze-frame data with a scan tool; note fuel temperature value and engine conditions
- Verify whether code is current, pending or historic; clear codes and attempt to reproduce
- Visually inspect sensor wiring and connector for damage, corrosion, bent pins or signs of fuel ingress
- Wiggle test harness while monitoring live fuel temp value to check for intermittent faults
- Measure sensor resistance at the sensor unplugged and compare to OEM chart for known ambient/fuel temperature (or compare to a known good sensor)
- Back-probe the sensor connector with key ON and measure reference voltage and signal voltage at the ECU connector
Signal parameters
- Sensor type: typically a 2-wire thermistor (NTC) mounted in the fuel rail or return; resistance decreases as temperature rises (confirm with OEM data)
- Typical interface: voltage divider to ECU. Expected signal voltage varies with temperature — commonly in the range ~0.2–4.5 V depending on fuel temperature (consult vehicle-specific chart)
- Open-circuit detection: ECU will report open if sensor circuit reads extremely high resistance or no signal (often >10–100 kΩ depending on design)
- Short-to-ground detection: very low resistance or near 0 V signal (thresholds vary; often
- Reference/pull-up voltage: often supplied internally by ECU (commonly 5 V reference) — verify on vehicle-specific wiring diagram
Diagnostic algorithm
- Connect a professional scan tool, read DTCs and freeze-frame data. Note fuel temperature reading, ignition state and engine running condition.
- Visually inspect the fuel-temp sensor and harness for physical damage, corrosion or fuel contamination. Repair obvious connector/harness faults.
- With ignition OFF, disconnect the sensor. Measure resistance across sensor terminals with a multimeter and compare to the manufacturer resistance vs temperature chart. If no chart available, compare to a known-good sensor.
- With key ON (engine OFF), back-probe the sensor connector: confirm ECU reference/pull-up voltage (usually ~5 V) and check signal voltage. If no reference, inspect wiring to ECU and related fuses/grounds.
- Wiggle the harness and connector while watching live fuel temperature signal on the scan tool to detect intermittent faults.
- Check continuity and resistance of the wiring between sensor and ECU; look for shorts to ground or power and high-resistance connections. Repair any wiring faults.
- If wiring and connector are good but sensor values are out-of-spec, replace the fuel temperature sensor. Use OEM or equivalent part.
- After repair, clear codes, perform relearn if required, and road-test to confirm the fault does not return. Re-scan to verify.
- Safety note: the fuel system contains flammable liquids and vapors. Work in a well-ventilated area, reduce ignition sources, and follow workshop safety procedures when disconnecting fuel components.
Likely causes
- Connector corrosion or bent/loose terminal at sensor or ECU
- Broken or shorted harness between sensor and ECU (often at harness flex points)
- Sensor element failed (thermistor open/short or drifted value)
- Contamination or fuel ingress causing sensor error
Fault status
Status
Fuel temperature sensor circuit malfunction — signal out of range (open/short/intermittent) detected by ECM; may cause default fuel temperature use and affect starting, idle and emissions.
Repair difficulty: Medium
Diagnostic time: 0.5-2 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email