Code Definition

P0669 — ECM/TCM internal temperature sensor circuit high

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0669

P0669 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0669 is stored, the module has detected a signal or supply voltage higher than the expected operating range; and a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0669 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The fault code P0669 is set when the Engine Control Module (ECM) or Transmission Control Module (TCM) detects a high voltage condition in the circuit of its internal temperature sensor. This high voltage situation suggests a potential short to power or an issue within the ECM or TCM affecting the sensor circuit. The internal temperature sensor is vital for monitoring the operating temperature of these control modules, ensuring they function within safe thermal limits. A high voltage in this circuit can cause inaccurate temperature readings, potentially leading to incorrect operational decision...

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