Speed Vehicle Signal Circuit Failure
Your vehicle's speed sensor isn't communicating properly with the engine computer, like a speedometer that's gone silent. The car can't read how fast you're going, which affects transmission shifting and stability control.
The ECM monitors the vehicle speed signal from wheel speed sensors (ABS sensors) or the transmission speed sensor. It checks for valid signal voltage transitions and compares them to expected values based on engine load and throttle position. A missing or inconsistent signal triggers the fault code.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Speed Sensor Signal Frequency | Continuous 0-5V pulses or CAN data stream | No signal, erratic pulses, or voltage out of range for >2 seconds |
| Signal Plausibility Check | Speed increases/decreases match throttle and engine load | Speed signal contradicts other sensor inputs |
Code C1445 is classified as a serious fault. If your check engine light is flashing — not just steady — pull over safely and do not continue driving. A flashing CEL indicates an active misfire or critical failure that can cause catalytic converter damage within minutes or permanent engine harm within miles. Contact a certified mechanic immediately. Do not attempt roadside repairs on high-severity codes unless you are trained to do so.
Once the fault is repaired, C1445 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.