Left Rear Sensor Circuit Failure
The left rear wheel speed sensor isn't communicating properly with your vehicle's anti-lock brake system (ABS). Think of it like a broken speedometer for that wheel—the system can't tell how fast it's spinning, so it can't prevent wheel lock-up during hard braking.
The ABS module monitors voltage signals from the left rear wheel speed sensor, which generates an AC signal proportional to wheel rotation speed. The ECU compares this signal against expected thresholds and detects open circuits, shorts, or signal loss.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Sensor Signal Voltage | 0.5–5V AC oscillating at wheel speed | No signal, constant voltage, or <0.1V |
| Signal Frequency | Proportional to vehicle speed (typically 5–100 Hz) | Zero frequency or erratic/missing pulses |
Code C1700 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, C1700 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.