P0183
PowertrainFuel Temperature Sensor A Circuit High Input
Most of the time this turns out to be a dead fuel temperature sensor or a corroded connector down by the fuel pump, rather than anything serious. The ECU watches the voltage coming back from that sensor, and when the reading climbs higher than it should the module reads that as a broken or open circuit and logs P0183. On a lot of cars the sensor lives inside the fuel pump module in the tank, which is why people groan when they hear it needs replacing.
ⓘ Information only. This page provides general educational information about fault code P0183. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0183 mean?
P0183 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Fuel Temperature Sensor A Circuit High Input.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine warning light on the dash, frequently the only thing you'll notice
- • Harder cold starts, especially first thing on a frosty morning
- • Slightly worse fuel economy, more obvious on a diesel doing short runs
- • Rough idle or a flat spot when you put your foot down
- • Down on power, and on some diesels a trip into limp mode
- • Plenty of cars show no driving symptoms at all beyond the light
Possible causes
Causes commonly associated with P0183, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Failed fuel temperature sensor, the usual answer. The internal element goes open circuit and the ECU sees the voltage spike
- 2. Corroded or fuel-soaked connector at the sensor or pump module, very common on older cars where the seal has gone
- 3. Damaged or chafed wiring in the sensor circuit, often where the loom rubs against the tank or chassis
- 4. Open circuit or a break in the signal wire back to the ECU, which gives the exact high-voltage reading this code describes
- 5. Overcharging from a faulty alternator pushing too much voltage through the system
- 6. ECU fault or out of date software, rare but it happens, usually only after everything else checks out
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Pull the codes and look at the freeze frame data. Check what temperature the sensor was reporting when it logged, a reading pinned at the cold extreme points straight at an open circuit
- 2. Get to the sensor connector and inspect it properly. Corrosion, green pins, or fuel residue on the contacts is a frequent find and a cheap fix
- 3. Back-probe the connector and check you've got reference voltage with the ignition on, usually around 5 volts. No reference means a wiring or ECU side problem, not the sensor
- 4. Measure the sensor's resistance with a multimeter and compare it to the workshop figures for the current fuel temperature. An open reading confirms a dead sensor
- 5. Wiggle-test the loom while watching live data to catch an intermittent break, particularly anywhere the harness flexes or rubs
- 6. If sensor and wiring both read fine, check charging voltage for an overcharging alternator before you start thinking about the ECU
Common questions about P0183
Should I buy a cheap sensor off eBay or pay for a proper one? +
For something buried in the fuel tank, fit a decent part and don't go back in twice. A genuine or quality branded fuel temperature sensor runs roughly £20 to £70. The no-name cheapies sometimes read slightly off or fail again in a year, and the labour to get the tank or pump back out dwarfs the few quid you saved. If it's an integrated pump module sensor you may be buying the whole module anyway, in which case stick with OE or a reputable aftermarket brand.
Can I keep driving with P0183 showing? +
Usually yes for a short while. The car will normally run, though you might see harder cold starts and a bit more fuel use while the ECU works off a default fuel temperature value. Some diesels will drop into limp mode if the reading is wild, which makes it gutless on the motorway. Sort it sooner rather than later, mainly because a flaky sensor reading can mess with cold-start fuelling.
Is this going to fail my MOT? +
The code on its own isn't a failure item, but if the engine warning light is lit when the tester looks at the dash, that's an automatic fail under current rules. Fix the cause and drive a few cycles so the light goes out before you book it in. If a duff sensor is fuelling the engine badly, a diesel could also trip the emissions or smoke side of the test.
What's it likely to cost to put right? +
If it's just the sensor and it's easy to reach, an independent garage might do it for £60 to £150 all in. Where the tank has to come down or the pump module needs replacing, you're more realistically looking at £200 to £400 once labour and the bigger part are included. A main dealer will typically charge a fair bit more for the same job, so for a car that's out of warranty an independent is the sensible call.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →