P0116 on Audi: How to Diagnose & Fix
Engine Coolant Temperature Sensor 1 Circuit Range/Performance
2 Audi models · 2 documented issues · $30-$700 repair
P0116 on Audi by model: symptoms, diagnosis and fix
The original black-housing dual coolant temperature sensor (G62) mounted in the coolant flange at the back of the cylinder head develops cracks and fails internally. The temperature sensor G2 (also known as G62) for the gauge has likely failed and is relatively easy to fix; it is located in the coolant flange at the back of the cylinder head and the early square-connector style and later elongated D-shaped black connector sensors are known problematic units. When it fails the ECU sees an implausible coolant temperature, leading to cold starting difficulties at low temperatures, poor idle and acceleration during warm up as well as an erratic or dead temperature gauge.
Common Symptoms
- erratic or dead coolant temperature gauge
- hard cold starts
- rough idle during warm-up
- poor fuel economy
- rich-running condition
- check engine light
How to Fix
Scan with VAG-COM/VCDS for fault 17664 / 16502 (P0118) and bench-test the sensor's resistance. From Bentley, the G62 test procedure: allow engine to cool to room temp (68F/20C), disconnect ECT sensor, connect multimeter to terminals 1 and 2; resistance must be 1500 to 3000 ohms — if not, replace the ECT. Replace with the updated green-top OEM sensor (part 059 919 501A) along with the retaining clip (032 121 142) and O-ring; replacing this sensor resolves running issues for many owners who are still using the original black sensor which had a high failure rate. Part is ~$25-40, DIY 30 minutes; shop labor brings total to ~$80-180.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Engine Coolant Temperature SensorCross-refTSE 1D
Fitment confirmed against the ShowMeTheParts catalog for this vehicle's year and engine.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (1)
Later A1s using the EA211 family (1.0 TFSI three-cylinder and revised 1.4 TFSI) have an integrated, belt-driven water pump with a plastic thermostat housing bolted to it (two thermostats — one for block, one for head). The plastic housing and seals become brittle and leak, and the assembly can also be attacked by oil from a leaking PCV. Coolant escapes through a weep hole or housing gasket, leading to low coolant and overheating risk.
Common Symptoms
- Coolant level dropping / low coolant warning
- Sweet coolant smell
- Visible coolant residue near pump
- Engine running hot or fluctuating temperature
How to Fix
Replace the complete coolant pump/thermostat assembly (rather than just the pump) with the updated part, as the plastic housings warp during partial disassembly. Replace seals and pressure-test the system. Special tools are needed for the thermostats.
Sources for this issue (1)
P0116 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0116 mean on a Audi?
P0116 stands for "Engine Coolant Temperature Sensor 1 Circuit Range/Performance." P0116 means the engine control module detected an engine coolant temperature (ECT) sensor reading that is within wiring limits but doesn't make sense — for example, it doesn't rise as the engine warms up, or it disagrees with other temperature data. The ECT sensor reports coolant temperature, which the computer uses for fuel mixture, ignition timing, cooling-fan control, and emissions monitors. An implausible reading can cause poor fuel economy, hard cold starts, or failed emissions readiness. It is generally drivable but should be fixed for proper engine management. On Audi it is documented across 2 models: A4, A1.
What are the most common causes of P0116?
The most common causes of P0116 are: Faulty or drifting engine coolant temperature sensor, Stuck-open thermostat (engine never reaches normal temp), Low coolant level or air in the cooling system, Wiring or connector resistance affecting the signal, Sensor reading inconsistent with intake-air temperature at cold start, Corroded sensor connector, PCM fault (less common). The specific cause varies by vehicle.
How much does it cost to fix P0116 on a Audi?
Published repair estimates on Audi range from $30 to $700 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0116 on a different make?
View P0116 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.