C1255
ABS Inlet Valve Coil RR Circuit Open
Chassis Chassis/Safety ABS System 🔴 Serious — Stop or limit driving
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What This Actually Means
In plain language — no jargon

The ABS system's right rear inlet valve coil has a broken electrical connection, like a light switch that won't make contact. Without this connection, the ABS can't control brake pressure at that wheel during emergency braking.

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

The ABS module monitors the coil resistance and continuity of the RR inlet valve solenoid circuit. During normal operation, the ECU sends a signal to energize the coil; an open circuit prevents current flow and is detected as a fault. The module performs continuity checks and voltage diagnostics on the coil winding.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Coil Resistance 4-8 ohms (typical solenoid coil) Infinite ohms or open circuit detected
Circuit Voltage Response 12V applied, current flows No current flow or voltage drop detected
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
RR ABS inlet valve solenoid connector
Inspect and reseat the electrical connector on the RR valve; clean corrosion from pins and test for proper seating.
2
ABS wiring harness (RR inlet valve circuit)
Check the wiring harness for breaks, pinches, or damaged insulation between the ABS module and RR valve; repair or replace damaged sections.
3
RR ABS inlet valve solenoid coil assembly
Replace the solenoid coil if connector and wiring are intact and resistance testing confirms an open coil.