B2179

Front Wiper Select Switch "A" Short to Ground

Body Chassis/Safety Wiper Control Circuit 🟢 Low — Fix at next service ✅ Safe to Drive
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What This Actually Means

In plain language — no jargon

The wiper control switch has an electrical short that's grounding the signal wire, like a loose wire touching the metal frame. The ECU can't properly read your wiper switch selection because the circuit is shorted to ground.

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Symptoms You May Notice

3 known symptoms for this code
Wipers inoperative or stuck in one position
Wiper controls unresponsive to selector lever input
Intermittent wiper operation or erratic behavior
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors the voltage signal from the wiper switch 'A' circuit, expecting specific voltage levels for each switch position (off, low, high, intermittent). When a short to ground exists, the voltage collapses to 0V continuously, preventing the ECU from distinguishing switch selections. The fault is triggered when the signal remains at ground potential when it shouldn't be.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Switch Signal Voltage 0.5V to 4.8V (varies by position) 0V or stuck at ground potential
Circuit Resistance Open to 10kΩ (position-dependent) <100Ω short to ground
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Wiper switch connector
Inspect the connector for moisture, corrosion, or loose pins and reseat or clean thoroughly.
2
Wiring harness (front section)
Check the wiring between the switch and column for pinched, cut, or abraded insulation causing a short.
3
Front wiper select switch assembly
Replace the switch if internal contacts are shorted or if cleaning and harness inspection reveal no external faults.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code B2179 is a low-severity fault. Your vehicle is generally safe to drive to a workshop for diagnosis. However, do not ignore it indefinitely — low-severity codes often indicate developing problems that become expensive if neglected. Book a diagnostic appointment within 2–4 weeks. If you notice any additional symptoms (rough running, power loss, unusual smells), treat it as higher priority.

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 B2179

What happens after you fix the fault

Once the fault is repaired, B2179 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.