P0182 — Fuel Temperature Sensor A Circuit Low — 5.9 Cummins Common Rail
Fuel Temperature Sensor A Circuit Low
What it means
The engine control module has detected a voltage signal from the fuel temperature sensor that is lower than the expected range.1
Most likely causes
- Fuel temperature sensor internal short or out-of-range low resistance — Sensor element or internal wiring pulls the signal toward ground, producing a low voltage reading at the ECM.1
- Wiring harness chafed/shorted to ground between sensor and ECM — Physical damage to the fuel-temperature sensor circuit causes a low-voltage condition seen by the ECM.1
- Connector corrosion or poor terminal contact at the fuel temperature sensor — Moisture/contamination increases resistance or creates a ground path, lowering the sensed voltage.1
- ECM input circuit fault for the fuel temperature sensor — Internal ECM pull-up or input circuitry fault results in a persistently low signal.1
How to diagnose
- Verify code P0182 is present and check freeze-frame for fuel temperature reading; confirm the code applies to 5.9L Cummins Common Rail 2003-2007.
- Inspect fuel temperature sensor connector and wiring for corrosion, moisture, or chafing; repair wiring faults before component replacement.
- Measure sensor supply/reference and signal voltages at the sensor connector with key on, engine off; compare to expected values and check for short to ground.
- Disconnect sensor and check ECM side for short to ground on signal wire; if short persists with sensor disconnected, inspect harness for ground fault.
- If wiring and connector are intact, test sensor resistance/voltage characteristic against specification; replace sensor if out of range.
- Clear codes, perform a road test and monitor fuel temperature PID to confirm signal returns to normal range.
Parts and tools you may need
- Digital multimeter
- Scan tool with live data
- Wiring diagram for 5.9L Cummins Common Rail 2003-2007
- Fuel temperature sensor
- Dielectric grease
- Terminal cleaning tools
Tools you’ll need
- digital multimeter — Measures sensor supply/reference and signal voltages at the sensor connector and checks for a short to ground on the signal wire with the sensor disconnected.
- OBD-II scan tool — Verifies P0182 is present, reviews freeze-frame fuel temperature data, and monitors the fuel temperature PID after repairs to confirm normal range.
- wiring repair kit — Repairs chafed, corroded, or moisture-damaged wiring and connector terminals found during harness inspection before replacing components.
- fuel temperature sensor tester — Tests the sensor’s resistance/voltage characteristic against specification to confirm an internal short or out-of-range low resistance.
Rough cost and difficulty
| Likely repair | Parts | Shop labor | Who usually does it |
|---|---|---|---|
| Wiring or connector repair | $10–$100 | 1–4 hrs | DIY with tools and a manual |
| Temperature or pressure sensor (coolant, intake air, oil, fuel temp) | $30–$150 | 0.3–1.5 hrs | Easy DIY |
| ECM/PCM replacement (programmed) | $600–$2,000 | 1–3 hrs | Shop |
Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.
When to see a pro
If wiring tests show no fault and a new sensor does not correct the low circuit reading, have the ECM input circuit evaluated by a qualified diesel technician. Do not attempt high-pressure fuel system service. If drivability symptoms persist, seek professional diagnosis.
Check for recalls
Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.
Sources
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