C1110

Code

Other C — Chassis

ABS Power Relay Coil Circuit Failure

Brand: Other

Type: C — Chassis

Views: UK: 27 EN: 30 RU: 33

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Page language: EN

Causes

Failed ABS power relay (open or shorted coil)
Blown fuse supplying relay or ABS module
Open, shorted or corroded wiring/connectors to relay coil
Poor ground or battery/charging system voltage low
Faulty ABS control module driver transistor or internal relay driver
Intermittent connector contact due to corrosion or water ingress

Symptoms

ABS warning lamp illuminated (often accompanied by traction control lamp)
Loss of ABS and/or traction control functions
ABS pump or valve(s) do not run/activate when braking under ABS conditions
Intermittent ABS operation or lights that occur in damp/wet conditions
Related drivability warnings or limp/failsafe behavior

What to check

Read and record all stored trouble codes and freeze-frame data with a scan tool
Visual inspection of ABS relay, fuse, connector and wiring for damage or corrosion
Check battery and charging system voltage at rest and while cranking
Swap relay with identical known-good relay (if available) and re-check
Measure relay coil resistance with multimeter
Backprobe relay socket and check for proper supply voltage and ground when ABS is commanded

Signal parameters

Typical relay coil resistance: ~50–200 ohms (varies by relay; check OEM spec)
Expected coil supply voltage: ~11–14 V (battery system voltage)
Typical coil current when energized: 50–250 mA (varies by relay)
Control method: often the ABS module grounds the coil to activate the relay (verify with wiring diagram)
No-voltage (open) or short-to-ground/short-to-Vb at coil pins indicates wiring/relay fault

Diagnostic algorithm

Record codes and freeze-frame data. Note any other related codes (voltage, comms, wheel sensors).
Perform a visual inspection: check the ABS power relay, relay socket, fuses, and wiring for corrosion, burnt terminals, or damage.
Verify battery voltage is within normal range (11–14 V). Low system voltage can cause relay/driving faults.
Check the fuse supplying the relay/ABS module and replace if blown. Re-test for recurrence.
With ignition ON (engine off), remove relay and measure coil resistance across the relay coil terminals. Compare to OEM spec. Infinite = open coil; very low = shorted coil.
Backprobe the relay socket: verify constant supply voltage at the power feed terminal and check the control terminal for switching (usually ground) while commanding ABS pump/relay with a scan tool or during a test condition. Have an assistant activate ABS request if needed.
If supply and control signals are correct at the socket but relay does not energize, replace the relay and retest.
If relay energizes but code returns, perform continuity and resistance checks from relay socket to ABS module control pin and to ground. Repair any damaged wiring or poor connections.
If wiring is good and connector pins are clean, suspect ABS module driver failure. Verify with oscilloscopic or module-level tests per service manual and consider module replacement only after wiring and relay verified.
Clear codes and perform road test to ensure ABS operates and the code does not return. Re-scan after test.

Likely causes

Corroded/loose relay socket or connector
Open coil inside ABS power relay
Blown fuse upstream of the relay
Damaged wiring harness between ABS module and relay/fuse
Faulty ABS module output that drives the relay coil (less common)

Fault status

⚠️ Status

C1110 – ABS Power Relay Coil Circuit Failure: open/short or improper drive of the ABS relay coil; ABS pump/valve may not receive power, disabling ABS/traction control.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours