P0183–P0188 Fuel Temperature Sensor A Circuit High
The voltage on this circuit is sitting near battery voltage. Typically a short to a positive feed, or a disconnected sensor floating high.
Can you drive it? The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.
Which code is which
Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.
| Code | Definition | Severity |
|---|---|---|
P0183 | Fuel Temperature Sensor A Circuit High | Investigate soon |
P0188 | Fuel Temperature Sensor B Circuit High | Investigate soon |
The definition
P0183: Fuel Temperature Sensor A Circuit High.
P0183 is a powertrain code (the engine or gearbox), defined by the SAE standard - it means the same thing on any make of car, and any generic OBD-II reader will decode it.
What to check first
Cheapest and fastest checks first:
- Unplug the sensor and check whether the signal falls. If it stays high, suspect the wiring rather than the sensor.
- Check the earth path - a missing earth makes a sensor read high.
What actually causes this on a VAG
'Circuit high' is the mirror image: the ECU sees a high signal voltage, which on this type of sender reads as impossibly cold fuel and almost always means the circuit is broken rather than the fuel being cold. An unplugged connector, a broken wire and a sensor that has gone open circuit all look identical to the ECU. The engine generally still runs because the ECU substitutes a default fuel temperature, though a diesel may be slightly rougher cold or smoke a little more.
Most likely causes, in order
- Connector off, not latched, or a broken locking tab. By far the most common cause, and it very often follows recent work - a fuel filter change, injection pump job, tank sender or anything that had the plug disturbed. Check the plug is fully home and has actually clicked, and that the latch is not snapped.
- Broken or corroded wire. Look along the whole run for a rub-through or a break, and check the connector for a pin that has been pushed back out of the body so it looks seated but makes no contact. Green corrosion inside the plug does the same thing.
- The sender has failed open circuit. Suspect this once the plug is confirmed good and the wiring checks out. Age and heat cycling in a hot fuel-damp location is enough on their own.
Worth knowing: You can often confirm this without buying a part, but identify the sensor before you touch it. On a plain two-wire temperature sender, with the ignition on and a scan tool showing live fuel temperature, briefly bridging the two pins in the disconnected plug should slam the reading to an implausibly hot value: if it does, the wiring and ECU are fine and the sender is the fault; if nothing changes, the break is in the harness. Do not do this on a combined pressure-and-temperature sensor - one of those pins is a live supply, and earthing it can damage the ECU. If you cannot confirm from the wiring diagram which type you have, skip the test and measure the sensor's resistance off the car instead.
Reading the code is the easy part
A code names the circuit that complained. What tells you why is watching the sensor behind it while the engine runs — and that is where a code reader stops and a diagnostic tool starts.
VAGPULSE reads every module in a VW, Audi, Skoda or SEAT — not just the engine — shows the live measuring blocks behind this fault, gives you the freeze-frame conditions it was logged under, and clears it once you have fixed it. It also does what a generic OBD reader cannot on a VAG: service resets, coding, adaptations, and Stage 1–3 flashing with your original file saved first.
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Common questions
What does P0183 mean?
P0183 means Fuel Temperature Sensor A Circuit High. The voltage on this circuit is sitting near battery voltage. Typically a short to a positive feed, or a disconnected sensor floating high.
Can I drive with P0183?
The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.