17664 on Audi
Engine Coolant Temperature Circuit (G62): Open / Short to B+
17664 on Audi vehicles indicates engine coolant temperature circuit (g62): open / short to b+. Au7o has documented this code across 1 Audi model — most commonly on A4. This VAG-specific fault code (OBD-II equivalent P1256) indicates the engine control module has detected an electrical fault in the Engine Coolant Temperature Sensor (G62) circuit — either an open circuit or a short to positive (B+). Because the ECM relies on coolant temperature to manage fuel delivery, ignition timing, and glow plug operation, a bad signal causes the engine to run on incorrect temperature data. Common symptoms include hard cold starts, high or irregular idle (1200–3000 RPM), poor warm-up acceleration, and erratic temperature gauge behavior. Typical repair costs on Audi range from $30 to $180, depending on the specific model and root cause.
Common Causes of 17664
- •Faulty Engine Coolant Temperature Sensor (G62) — original black sensors on 1995–2002 VWs are a known failure point, replaced by green units
- •Open or broken wiring between the sensor and the ECM
- •Short to positive (B+) in the sensor wiring
- •Corroded, loose, or damaged sensor connector
- •Wiring harness chafing or insulation damage near the sensor
17664 on Audi by Model
Audi A4(1 issue)
- G62 Engine Coolant Temperature Sensor (black-housing) fails causing erratic temp gauge, hard cold starts and rich-running1996-2001
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.
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What does 17664 mean on Audi?▼
17664 stands for "Engine Coolant Temperature Circuit (G62): Open / Short to B+." This VAG-specific fault code (OBD-II equivalent P1256) indicates the engine control module has detected an electrical fault in the Engine Coolant Temperature Sensor (G62) circuit — either an open circuit or a short to positive (B+). Because the ECM relies on coolant temperature to manage fuel delivery, ignition timing, and glow plug operation, a bad signal causes the engine to run on incorrect temperature data. Common symptoms include hard cold starts, high or irregular idle (1200–3000 RPM), poor warm-up acceleration, and erratic temperature gauge behavior. On Audi specifically, this code is documented across 1 model.
What causes 17664 on Audi vehicles?▼
Common causes on Audi: Faulty Engine Coolant Temperature Sensor (G62) — original black sensors on 1995–2002 VWs are a known failure point, replaced by green units, Open or broken wiring between the sensor and the ECM, Short to positive (B+) in the sensor wiring, Corroded, loose, or damaged sensor connector, Wiring harness chafing or insulation damage near the sensor. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix 17664 on a Audi?▼
Repair costs on Audi range from $30 to $180, depending on the specific model and root cause.
Which Audi models have 17664 documented?▼
Au7o has documented 17664 on 1 Audi model: A4.