Diesel Trouble Codes

P0182 — Fuel Temperature Sensor A Circuit Low (5.9 Cummins Common Rail)

Fuel Temperature Sensor A Circuit Low

Updated September 2, 2026

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

  1. 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
  2. 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
  3. 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
  4. 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

  1. 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 per platform facts.
  2. Inspect fuel temperature sensor connector and wiring for corrosion, moisture, or chafing; repair wiring faults before component replacement.
  3. 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.
  4. Disconnect sensor and check ECM side for short to ground on signal wire; if short persists with sensor disconnected, inspect harness for ground fault.
  5. If wiring and connector are intact, test sensor resistance/voltage characteristic against specification; replace sensor if out of range.
  6. Clear codes, perform a road test and monitor fuel temperature PID to confirm signal returns to normal range.

Parts and tools you may need

Rough cost and difficulty

Parts cost varies by supplier; labor depends on sensor location and harness access. Diagnose before replacing components.

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.

Sources

  1. Curated DTC seed — 5.9 Cummins Common Rail (curated) ↩︎ ↩︎ ↩︎ ↩︎ ↩︎