What Does C1112 Mean?
This code indicates the ABS control module has detected a short circuit to ground in the power relay coil circuit. The ABS system uses a power relay to control main electrical power to the hydraulic pump motor and solenoid valves. When the control module detects abnormally low resistance or voltage in the relay coil control circuit, it sets this code and typically disables ABS functionality while retaining normal braking operation.
Common Causes
45%
Damaged wiring harness or chafed insulation causing short to ground in relay coil control circuit
30%
Failed ABS power relay with internal short circuit in coil windings
15%
Corroded or moisture-damaged relay socket causing intermittent ground fault
10%
Failed ABS control module with shorted relay driver circuit
Diagnostic Steps
1
Step 1: Perform visual inspection of ABS power relay location, check for water intrusion, corrosion, or damaged connector pins. Remove relay and inspect socket terminals for corrosion, melting, or bent pins.
2
Step 2: Using a digital multimeter, test the removed relay coil resistance between terminals (typically pins 85 and 86). Expected reading should be 70-120 ohms. Reading near zero ohms confirms internal short circuit in relay.
3
Step 3: With relay removed and ignition off, measure resistance from relay coil control wire terminal at socket to chassis ground. Reading should be infinite (open circuit). Low resistance indicates wiring harness short to ground.
4
Step 4: Trace wiring harness from relay socket to ABS control module, inspecting for pinched, chafed, or damaged insulation particularly at flex points, frame rails, and harness routing clips. Use multimeter continuity test to isolate short location.
5
Step 5: If wiring and relay test normal, check ABS control module relay driver output using waveform or voltage test with module connected. Measure voltage at relay control terminal with ignition on - should show battery voltage until relay energized. Constant ground voltage indicates failed module driver circuit.
6
Step 6: After repairs, clear codes, test ABS system operation through test drive including multiple ABS activation events at safe speeds. Verify code does not return and ABS warning lamp remains off.
Estimated Repair Cost
$100 - $800
Parts + labor, varies by vehicle and location
This code indicates the ABS control module has detected a short circuit to ground in the power relay coil circuit. The ABS system uses a power relay to control main electrical power to the hydraulic pump motor and solenoid valves. When the control module detects abnormally low resistance or voltage ...
The most common cause of C1112 (ABS Power Relay Coil Short Circuit To Ground) is: Damaged wiring harness or chafed insulation causing short to ground in relay coil control circuit
Typical repair costs for C1112 range from $100 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle is safe to drive as normal braking function remains operational, but ABS functionality will be disabled. This means wheels may lock during hard braking on slippery surfaces, increasing stopping distances and reducing steering control. Repair should be completed promptly, especially if driving in adverse weather conditions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1112 to identify the root cause.
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Quick Info
Category
Chassis
System
Anti-lock Braking System (ABS)
Difficulty
Type
Manufacturer
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