C1705

Left Rear Center Sensor Circuit Short to Vbat

Chassis Chassis/Safety ABS sensor circuit 🔴 Serious — Stop or limit driving 🚫 Do Not Drive
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What This Actually Means

In plain language — no jargon

The left rear center sensor is sending a signal that's shorted directly to battery voltage, like a wire touching the positive terminal when it shouldn't. The ECU expects a variable signal but instead gets stuck at maximum voltage.

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Symptoms You May Notice

3 known symptoms for this code
ABS or stability control warning light illuminated
Reduced braking performance or loss of ABS function
Traction control disabled or non-functional
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors the left rear center sensor (typically a wheel speed or pressure sensor) for a signal between ground and battery voltage. When the circuit shorts directly to Vbat, the sensor voltage remains at maximum instead of fluctuating with wheel speed or brake pressure changes. The ECU detects this constant high voltage and recognizes an abnormal circuit condition.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Sensor voltage 0.5V to 4.5V (variable) Constant Vbat (12-14V)
Signal impedance 1-2 kΩ <0.5 Ω (short to power)
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Wiring harness connector
Inspect the connector at the left rear center sensor for corrosion, loose pins, or water intrusion and clean or reseat as needed.
2
Sensor wiring
Trace the sensor wire harness for pinches, cuts, or areas where insulation is damaged and allowing contact with vehicle power.
3
Left rear center sensor
Replace the sensor if wiring and connectors test good, as internal shorts within the sensor are common.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code C1705 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.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
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How to Clear Code C1705

What happens after you fix the fault

Once the fault is repaired, C1705 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.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.