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P0117AudiAudi A6 HubAll Audi P0117High Severity

P0117 on Audi A6

Engine Coolant Temperature Sensor 1 Circuit Low

Factory diagnostic protocol and troubleshooting wire for fault code P0117 specifically for the Audi A6 (2020–2026, 3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro).

Verified OEM Telemetry & Field Repair Tree
Audi A62020–2026
Audi A6
Sedan3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
A6 SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Not Recommended
High urgency level
Est. Repair Cost
$80 - $250 (DIY: $20 - $60)
Parts & Labor DIY
Check P0117 On Another Audi Model:
Diagnose P0117 on Specific A6 Model Year:

1. Symptoms of P0117 on Audi A6

When the Engine Control Module (ECM/PCM) on your Audi A6 (3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro) logs fault code P0117, drivers commonly observe:

Check Engine Light on on Audi A6 (3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro)
Radiator radiator fans running constantly at high speed on Audi A6 (3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro)
Temperature gauge pegged at maximum H or not reading on Audi A6 (3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro)
Engine hard starting when cold (flooding from excess fuel) on Audi A6 (3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro)
Poor gas mileage and rough idling on Audi A6 (3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro)
Audi A6 OBD-II Port Location
The 16-pin diagnostic connector is located Driver lower dash trim near parking brake assembly. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Audi A6

Historical warranty claims and technical repair bulletins for Audi A6 point to the following failure distribution:

55%
ECT sensor internal short to ground (Audi OEM Part)
25%
Short circuit to ground in ECT signal wiring harness (Audi OEM Part)
12%
Damaged, corroded, or water-contaminated ECT connector (Audi OEM Part)
8%
Faulty PCM / ECM analog input circuit (Audi OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Audi A6.

3. Step-by-Step DIY Repair Guide for Audi A6

01
Scan ECT Temperature Data

Read ECT live PID on scanner. If it reads 284°F (140°C) or higher with engine cold, a short to ground exists. on the Audi A6 equipped with 3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro.

Required Tool: OBD-II Scanner
02
Unplug ECT Sensor Connector

Unplug sensor connector while watching live data. If temperature drops to -40°F (-40°C), the sensor itself is shorted. on the Audi A6 equipped with 3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro.

Required Tool: OBD-II Scanner
03
Inspect Wiring Harness

If reading stays pegged at max with sensor unplugged, inspect harness for pinch points grounding against engine block. on the Audi A6 equipped with 3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro.

Required Tool: Digital Multimeter
04
Replace Engine Coolant Temperature Sensor

Allow engine to cool, unscrew old ECT sensor from coolant crossover pipe or thermostat housing, install new OEM sensor with fresh thread sealant. on the Audi A6 equipped with 3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro.

Required Tool: 19mm Deep Socket, Ratchet, Coolant Catch Pan
05
Top off Coolant & Clear Codes

Bleed air from cooling system, clear DTCs, and verify normal temperature rise on live data. on the Audi A6 equipped with 3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro.

Required Tool: Coolant Funnel Kit, OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Audi A6 (P0117)

Prime Fast Delivery & Verified Fitment
Variable Valve Timing (VVT)

VVT Oil Control Solenoid Valve

4.6 / 5.0 (Direct Fit)

Restores accurate camshaft timing and oil pressure regulation on Audi A6.

$34 – $65 Prime
Check Fitment on Amazon
Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
View on Amazon
Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for Audi A6Verified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Audi A6

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Audi A6:

4. Audi A6 P0117 FAQs

What causes code P0117 to trigger on a Audi A6?

On the Audi A6 (3.0L Turbo V6 (A7/A8 S6 450HP) / 2.0L TFSI 261HP / 55 TFSI quattro), P0117 is most frequently caused by ECT sensor internal short to ground or Short circuit to ground in ECT signal wiring harness.

Where is the OBD-II port located on my Audi A6?

On the Audi A6, the 16-pin DLC diagnostic connector is located Driver lower dash trim near parking brake assembly. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Audi A6 with code P0117?

No. The ECU thinks the engine is at 280°F+ (overheating) and runs rich or disables cooling fan logic. Given that P0117 carries a High severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.