C1204
ABS Outlet Valve Coil Rear Circuit Short To Battery
Chassis Chassis/Safety ABS Electrical 🔴 Serious — Stop or limit driving
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What This Actually Means
In plain language — no jargon

The ABS rear outlet valve coil has an electrical short that's sending too much current directly to the battery instead of cycling properly. Think of it like a water valve that's stuck open—the electrical signal can't control the brake pressure like it should.

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Symptoms You May Notice
3 known symptoms for this code
ABS warning light illuminated on dashboard
Reduced or no ABS function during braking
Possible brake pedal pulsation or hard braking response
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors coil resistance and voltage feedback from the rear ABS outlet valve circuit. When the coil shorts to battery voltage, the ECU detects abnormal current draw and voltage levels that exceed normal operating parameters. The fault is confirmed when voltage remains high despite command signals being inactive.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Coil Resistance 4-15 ohms (varies by manufacturer) Less than 2 ohms or open circuit
Circuit Voltage 0V when inactive, 12V when commanded Continuous 12V or battery voltage present
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
ABS outlet valve wiring harness connector
Inspect connector for corrosion, loose pins, or water intrusion; clean or reseat connections.
2
ABS outlet valve coil wiring
Check for pinched, damaged, or melted insulation along the wire path; repair or replace damaged sections.
3
Rear ABS outlet valve assembly
Replace the valve if internal coil winding is shorted and cannot be repaired through wire inspection.