How severe is fault code C1273?

Serious — Stop or limit driving

OBD Code C1273: Motor # 2 Input Circuit Short to Vbat

Q: What does OBD code C1273 mean?

Motor # 2 Input Circuit Short to Vbat. Motor #2 (typically an auxiliary motor or solenoid) has a wiring short that's connecting it directly to battery voltage when it shouldn't be. This is like a light switch stuck in the ON position, draining power and preventing normal operation.

Q: What are the symptoms of fault code C1273?

ABS warning light or stability control light illuminated, Loss of ABS or traction control functionality, Possible battery drain or electrical burning smell

Q: How do I fix OBD fault code C1273?

Locate and inspect the Motor #2 wiring for damaged insulation, pinch points, or corrosion; repair or replace the affected wire segment.. Disconnect and clean the connector pins; check for corrosion, bent pins, or moisture that could cause a short.. If wiring is intact, the motor itself may have internal short; replace the motor assembly.

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What This Actually Means

In plain language — no jargon

Motor #2 (typically an auxiliary motor or solenoid) has a wiring short that's connecting it directly to battery voltage when it shouldn't be. This is like a light switch stuck in the ON position, draining power and preventing normal operation.

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Symptoms You May Notice

3 known symptoms for this code

ABS warning light or stability control light illuminated

Loss of ABS or traction control functionality

Possible battery drain or electrical burning smell

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Embedded Systems Insight

What the ECU/ECM is actually computing

The ECU monitors the voltage input on Motor #2's control circuit. The circuit should cycle between ground and operating voltage under normal conditions. A short to Vbat (battery voltage) means the ECU detects continuous battery voltage when the motor should be off, indicating insulation failure or a direct short in the wiring harness.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Motor #2 Input Voltage	0V (off) to 5V-12V (modulated control)	Constant Vbat (12-14V) regardless of command state
Circuit Resistance	>10 kΩ when de-energized	<100Ω (direct short path to battery)

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Wiring harness inspection/repair

Locate and inspect the Motor #2 wiring for damaged insulation, pinch points, or corrosion; repair or replace the affected wire segment.

2

Motor #2 connector

Disconnect and clean the connector pins; check for corrosion, bent pins, or moisture that could cause a short.

3

Motor #2 solenoid/motor assembly

If wiring is intact, the motor itself may have internal short; replace the motor assembly.