17664 on 1996-2001 Audi A4 — Engine Coolant Temperature Circuit (G62): Open / Short to B+
1 vehicles · 1 makes · $30-$180 repair
Most Reported On
17664 is an OBD-II diagnostic trouble code meaning “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. This code is most commonly reported on 1996-2001 Audi A4, with repair costs ranging from $30 to $180.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose 17664, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all 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
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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FAQ
What does 17664 mean?
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.
What are the most common causes of 17664?
The most common causes of 17664 are: 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. The specific cause varies by vehicle.
How much does it cost to fix 17664?
Repair costs for 17664 range from $30 to $180, depending on the vehicle and root cause.
Which vehicles are affected by 17664?
Au7o has documented 17664 across 1 vehicle models from 1 manufacturers: Audi.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.