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P017CCriticalEngine Cooling / Engine Control Module (J623)

P017C: Cylinder Head Temperature Sensor - Short Circuit to Ground

2 vehicles · 1 makes

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Most Reported On

2020-2021Audi RS Q82020-2021Audi SQ8

P017C is an OBD-II diagnostic trouble code meaning “Cylinder Head Temperature Sensor - Short Circuit to Ground.” The engine control module sees the cylinder head temperature sensor signal pulled to ground - a short-to-ground condition on the sensor circuit, which the ECM reads as an impossibly high temperature. On the Audi 4.0T V8 documented in TSB 2062951, this is typically caused by water intrusion past a damaged O-ring inside the plastic housing of coolant temperature sender G407, which bridges the sensing circuit. This code is most commonly reported on 2020-2021 Audi RS Q8, and 2020-2021 Audi SQ8.

On This Page

  • Common Causes
  • Vehicles (2)
  • Related Codes
  • FAQ
  • Sources (1)
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Common Causes

1Moisture inside the G407 coolant temperature sender housing from a damaged O-ring (Audi TSB 2062951)
2Chafed or pinched sensor wiring shorting to chassis ground
3Coolant or water in the sensor connector
4Internally shorted temperature sensor element

Diagnostic Tools

This is a powertrain code, so a basic OBD-II reader can read it. These read P017C.

Reads P codes$20–$40

ANCEL AD310 Classic OBD-II Scanner

by ANCEL

A simple code reader for engine (P) codes on many compatible OBD-II vehicles. It does not support every vehicle or hybrid/EV application, and it does NOT read body, chassis or network codes; confirm exact-vehicle compatibility before buying.

  • ✓Read & clear engine (P) codes
  • ✓View freeze frame data
  • ✓I/M readiness status
  • ✓No batteries or app needed
Check Price on Amazon
Reads P codes$90–$120

BlueDriver Pro Bluetooth Scanner

by BlueDriver

Bluetooth scanner with a companion app that reads beyond the engine module — ABS, SRS and transmission — plus manufacturer-specific codes on many vehicles.

  • ✓Enhanced diagnostics (ABS, SRS, transmission)
  • ✓Repair Reports with verified fixes
  • ✓Smog check readiness
  • ✓Free app (iOS & Android)
Check Price on Amazon
Reads P codes$180–$230

LAUNCH CRP123X V3.0 Elite OBD-II Scanner

by LAUNCH

Handheld scanner covering the four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.

  • ✓Engine, transmission, ABS, SRS diagnostics
  • ✓Live data stream & graphing
  • ✓AutoVIN for vehicle identification
  • ✓Free lifetime updates via Wi-Fi
Check Price on Amazon
Reads P codes$350–$450

Autel MaxiCOM MK808S Diagnostic Tool

by Autel

Shop-level tablet with all-system coverage and bi-directional control, so you can command a module rather than only read it.

  • ✓All-system diagnostics (25+ modules)
  • ✓Bi-directional control & active tests
  • ✓Oil reset, EPB, BMS, TPMS, injector coding
  • ✓7-inch touchscreen with Android OS
Check Price on Amazon

What you can do yourself, and what needs a shop

Reading the code, clearing it, and watching whether it returns is a driveway job with the right scanner. These steps are not:

  • •Module programming or software updates — needs the manufacturer software or a J2534 pass-through with a paid subscription.
  • •Replacing a control module — most are VIN-programmed and immobilizer-registered, so a new one does nothing until it is coded to your car.
  • •Airbag/SRS component work — a stored fault can deploy a live device.

If the vehicle is still under warranty, check for an open recall or technical service bulletin before buying anything — the repair may already be covered.

As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.

Vehicles Affected (2)

Audi P017C page →
RS Q8Moderate

2020-Early 2021 RS Q8 Red Coolant Warning - Check G407 per TSB 2062951/4

2020-2021
SQ8Moderate

2020-Early 2021 SQ8 Red Coolant Warning - Check G407 per TSB 2062951/4

2020-2021

Related Codes (4)

P0170Fuel Trim Malfunction (Bank 1)P0171System Too Lean (Bank 1)P0172System Too Rich (Bank 1)P0173Fuel Trim Malfunction (Bank 2)

FAQ

What does P017C mean?

P017C stands for "Cylinder Head Temperature Sensor - Short Circuit to Ground." The engine control module sees the cylinder head temperature sensor signal pulled to ground - a short-to-ground condition on the sensor circuit, which the ECM reads as an impossibly high temperature. On the Audi 4.0T V8 documented in TSB 2062951, this is typically caused by water intrusion past a damaged O-ring inside the plastic housing of coolant temperature sender G407, which bridges the sensing circuit.

What are the most common causes of P017C?

The most common causes of P017C are: Moisture inside the G407 coolant temperature sender housing from a damaged O-ring (Audi TSB 2062951), Chafed or pinched sensor wiring shorting to chassis ground, Coolant or water in the sensor connector, Internally shorted temperature sensor element. The specific cause varies by vehicle.

How much does it cost to fix P017C?

Repair costs vary widely depending on the root cause and vehicle.

Which vehicles are affected by P017C?

Au7o has documented P017C across 2 vehicle models from 1 manufacturers: Audi.

Sources (1)

  • TSBAudi TSB 2062951/4 - Red Coolant Warning and G407 Temperature-Sender Diagnosis
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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