C1105

Traction Control Disable Lamp - Circuit Short to Battery

Chassis Chassis/Safety Traction Control Lamp Circuit 🔴 Serious — Stop or limit driving 🚫 Do Not Drive
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What This Actually Means

In plain language — no jargon

The traction control disable lamp circuit is shorted directly to battery power, preventing the ECU from controlling the warning light properly. It's like a light switch that's stuck in the 'on' position because someone bypassed the actual switch with a direct wire.

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Symptoms You May Notice

3 known symptoms for this code
Traction control disable lamp stays on continuously
Lamp does not respond to ignition cycle or vehicle operation
ABS or stability control systems may be disabled or in limp mode
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors the traction control disable lamp circuit voltage, which should be low (near ground) when off and pulled high through a driver circuit when on. A short to battery keeps the voltage at battery level regardless of ECU commands, preventing normal lamp control and signaling a wiring or driver fault.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Lamp circuit voltage 0V (off) or 12V (on, ECU-controlled) Stuck at 12V regardless of ECU command
Output driver current draw 0.5-2.0A when lamp commanded on High resistance or open circuit detected
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Wiring harness inspection
Trace the lamp circuit from BCM/ECU to lamp for pinched, abraded, or corroded wires causing shorts to body ground or power.
2
Traction control disable lamp connector
Inspect and reseat the lamp connector; clean corrosion from pins and ensure proper seating to restore normal circuit voltage.
3
BCM/ECU output driver circuit
If wiring is good, the lamp driver transistor inside the module may be failed; module reprogramming or replacement is needed.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code C1105 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 C1105

What happens after you fix the fault

Once the fault is repaired, C1105 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.