P017B on Audi
Cylinder Head Temperature Sensor - Implausible Signal
P017B on Audi vehicles indicates cylinder head temperature sensor - implausible signal. Au7o has documented this code across 2 Audi models — most commonly on RS Q8, SQ8. The engine control module has compared the cylinder head temperature sensor signal against other thermal models and sensors and found it implausible - the value is out of range, drifting, or inconsistent with expected engine warm-up behaviour. On the Audi 4.0T V8 this is documented in TSB 2062951 (A8, S8, Q7, SQ7, Q8, SQ8, RS Q8, RS 6, RS 7) alongside P218100, where a damaged O-ring lets water into the plastic housing of coolant temperature sender G407 and corrupts the sensing element. The loss of function is often intermittent.
Common Causes of P017B
- •Damaged O-ring on coolant temperature sender G407 allowing moisture into the sensor housing (Audi TSB 2062951)
- •Failed or drifting cylinder head temperature sensor element
- •Corroded sensor connector or damaged wiring
- •Genuine cooling system problem (low coolant, air pocket, failed thermostat or water pump) producing real out-of-range temperatures
P017B on Audi by Model
Audi RS Q8(1 issue)
- 2020-Early 2021 RS Q8 Red Coolant Warning - Check G407 per TSB 2062951/42020-2021
Audi TSB 2062951/4 covers all 2020 RS Q8 vehicles and early-production 2021 vehicles through chassis WUARRDF11MD011353 when a red coolant warning appears and the engine controller stores P218100, P017B00, P017C00 or P017E00. Audi documents that a damaged or pinched O-ring can allow moisture to reach coolant temperature sender G407. This bounded sensor condition does not establish universal turbo-coolant hose, pump or heat-related failure.
Audi SQ8(1 issue)
- 2020-Early 2021 SQ8 Red Coolant Warning - Check G407 per TSB 2062951/42020-2021
Audi TSB 2062951/4 covers all 2020 SQ8 vehicles and early-production 2021 vehicles through chassis WA1CWBF17MD010458 when a red coolant warning appears and the engine controller stores P218100, P017B00, P017C00 or P017E00. Audi documents that a damaged or pinched O-ring can allow moisture to reach coolant temperature sender G407. This bounded sensor condition does not establish universal turbo-coolant hose, pump or heat-related failure.
Looking for P017B on a different make?
View P017B across all makes →Frequently Asked Questions
What does P017B mean on Audi?▼
P017B stands for "Cylinder Head Temperature Sensor - Implausible Signal." The engine control module has compared the cylinder head temperature sensor signal against other thermal models and sensors and found it implausible - the value is out of range, drifting, or inconsistent with expected engine warm-up behaviour. On the Audi 4.0T V8 this is documented in TSB 2062951 (A8, S8, Q7, SQ7, Q8, SQ8, RS Q8, RS 6, RS 7) alongside P218100, where a damaged O-ring lets water into the plastic housing of coolant temperature sender G407 and corrupts the sensing element. The loss of function is often intermittent. On Audi specifically, this code is documented across 2 models.
What causes P017B on Audi vehicles?▼
Common causes on Audi: Damaged O-ring on coolant temperature sender G407 allowing moisture into the sensor housing (Audi TSB 2062951), Failed or drifting cylinder head temperature sensor element, Corroded sensor connector or damaged wiring, Genuine cooling system problem (low coolant, air pocket, failed thermostat or water pump) producing real out-of-range temperatures. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P017B on a Audi?▼
Repair costs vary widely depending on the root cause and specific Audi model.
Which Audi models have P017B documented?▼
Au7o has documented P017B on 2 Audi models: RS Q8, SQ8.