OBD-II Code P0182 — What It Means & How to Fix It

What Does This Error Mean?

P0182 means the fuel temperature sensor is sending an abnormally low voltage signal to the ECM. A low voltage signal makes the computer think the fuel is extremely cold — even when it isn't. This can cause the ECM to over-fuel the engine thinking it needs a cold-weather enrichment. The most likely causes are a short circuit in the wiring or a failed sensor. This code is most common on diesel-powered trucks.

Affected Models

Diesel vehicles across all makes 1996+
Common in Ford F-250/350 Power Stroke
Common in Chevy Silverado HD Duramax
Common in Ram 2500/3500 Cummins
Common in Volkswagen TDI diesel models

Common Causes

Short to ground in the sensor signal wire causing artificially low voltage
Failed fuel temperature sensor with an internal short circuit
Water intrusion into the sensor connector creating a short
Pinched or damaged wiring harness creating a short to chassis ground
ECM fault causing incorrect reference voltage to the sensor circuit

How to Fix It

Unplug the fuel temperature sensor connector and check whether the code clears or the live data reading changes significantly. If the reading jumps to normal after unplugging the sensor, the sensor itself is shorted internally.

With the connector unplugged, the ECM sees an open circuit and may set P0183 (high input) instead. That's actually useful information — it confirms the sensor is the short source.
Inspect the sensor connector for moisture or corrosion. Water inside the connector can create a low-resistance path to ground, mimicking a sensor short. Dry out the connector, treat it with electrical contact cleaner, and use dielectric grease when reassembling.

Dielectric grease prevents future moisture intrusion and corrosion. A small tube costs about $3 at any auto parts store.
Use a multimeter to measure resistance across the sensor terminals with it still plugged in. A reading close to zero ohms (near short) when the fuel is at normal temperature confirms the sensor is faulty. Normal resistance at room temperature is typically 1,000-3,000 ohms depending on the sensor.

Reference your repair manual for the correct resistance value at a known temperature for your specific sensor.
Replace the fuel temperature sensor if tests confirm a low-resistance reading. Locate the sensor in or near the fuel rail or injection pump, drain any residual fuel pressure, and swap in the new sensor. Use thread sealant if specified by the manufacturer.

Some fuel temperature sensors are integrated into larger assemblies (like a filter housing module) and require replacing the whole module.
If the new sensor still causes P0182, use a multimeter to check for a short to ground in the wiring harness. Disconnect the sensor connector and ECM connector, then measure resistance between the signal wire and chassis ground. A reading near zero means the wire is shorted somewhere between the two connectors.

Wiring shorts in the engine bay are often caused by the harness rubbing on a sharp metal edge over time.

When to Call a Professional

If replacing the sensor doesn't fix P0182, have a mechanic trace the wiring for a short to ground. A wiring short can be anywhere along the harness from the sensor to the ECM — often dozens of feet of wire. Professional technicians use wiring diagrams and resistance tests to pinpoint shorts quickly. Diagnosis costs $75-$150 and is much faster than inspecting every inch of wire yourself.

Frequently Asked Questions

Will P0182 affect how my diesel runs?

It can. If the ECM thinks the fuel is extremely cold, it may add extra fuel during injection cycles — essentially running the engine slightly rich. On modern common-rail diesels, this can increase soot production and black smoke. Long-term, running rich accelerates diesel particulate filter (DPF) clogging. Fix it before it causes secondary problems.

Can P0182 appear on gasoline vehicles too?

Yes, but it's rare. Most modern gasoline vehicles don't have a fuel temperature sensor — fuel temperature management is handled differently. P0182 on a gasoline vehicle usually indicates a specific turbocharged model or a unique fuel system configuration. Check if your vehicle even has this sensor before starting diagnosis.

How do I know if my fuel temperature sensor is shorted vs. the wiring is shorted?

Unplug the sensor connector. If the P0182 code clears or the voltage reading rises to normal after unplugging, the short is inside the sensor. If the code and low-voltage reading persist even with the sensor unplugged, the short is in the wiring between the connector and the ECM. This simple test tells you exactly where to focus your repair.