C1111
ABS Power Relay Coil Open Circuit
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 system's power relay has an open circuit in its coil, meaning electrical current cannot flow through it to activate the relay. Think of it like a broken light switch that won't turn on no matter how many times you flip it.

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Symptoms You May Notice
3 known symptoms for this code
ABS warning light illuminated on dashboard
ABS system inoperative; brakes lock up under hard braking
Loss of traction control functionality
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors the resistance and continuity of the ABS power relay coil circuit during system initialization and operation. It expects a specific resistance range when the relay is de-energized and verifies the coil can be energized via voltage application. An open circuit (infinite resistance) triggers the fault code.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Relay Coil Resistance 20-80 ohms Infinite ohms (open circuit)
Relay Coil Supply Voltage 10-14.5V during activation No voltage drop across coil due to open
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
ABS Power Relay
Locate the relay in the engine bay or under-dash fuse box, remove the failed unit, and install a new OEM or quality aftermarket relay.
2
Relay connector and wiring harness
Inspect the relay socket pins and wiring for corrosion or damage; clean contacts with contact cleaner or replace connector if bent.
3
ABS control module fuse
Check the dedicated ABS fuse in the fuse box for blown condition; replace with correct amperage if needed.