C0113 DTC: ABS Pump Motor Circuit Intermittent

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C0113 DTC: ABS Pump Motor Circuit Intermittent

Diagnostic Trouble Code (DTC) C0113 indicates that the ABS control module has detected an intermittent fault in the ABS pump motor circuit. Instead of a constant electrical failure, the pump motor voltage or control signal is lost only occasionally. This causes the ABS module to disable Anti-lock Braking System (ABS), Traction Control System (TCS), and Electronic Stability Control (ESC) until the fault is corrected.

What Does C0113 Mean?

The ABS pump motor is activated only when the hydraulic control unit needs to restore brake pressure during ABS operation. If the control module detects unstable voltage, intermittent continuity, or temporary signal loss in the pump motor circuit, it stores DTC C0113. These faults are often difficult to reproduce because they may only occur while driving over bumps, during vibration, or when temperature changes affect electrical connections.

Affected Vehicle Systems

  • Anti-lock Braking System (ABS)
  • Electronic Stability Control (ESC)
  • Traction Control System (TCS)
  • Brake Hydraulic Control Unit (HCU)
  • ABS Pump Motor Circuit

Typical System Diagram

Battery (+)
│
▼ ABS Fuse
│
▼ Pump Relay
│
▼ ABS Pump Motor
│
≈≈≈ Intermittent Connection
▼ ABS Control Module

Typical Pump Motor Pinout

Pin 1 → Battery Voltage (B+)
Pin 2 → Ground
Pin 3 → Pump Motor Control
Pin 4 → Pump Feedback (if equipped)

Common Symptoms

  • ABS warning light turns ON and OFF intermittently.
  • Traction Control warning light appears randomly.
  • ESC warning lamp illuminated.
  • ABS operates normally at times, then becomes unavailable.
  • Intermittent brake pedal pulsation.
  • DTC may clear temporarily after restarting the vehicle.

Possible Causes

  • Loose ABS pump connector.
  • Corroded electrical terminals.
  • Broken wiring inside the harness.
  • Faulty ABS pump relay.
  • Intermittent pump motor failure.
  • Poor chassis ground.
  • Water intrusion inside the ABS connector.
  • Internal ABS control module fault.

Driving Risk Level

Risk Level: HIGH

The vehicle usually retains normal hydraulic braking, but ABS, TCS, and ESC may stop working without warning. Because the failure is intermittent, the warning lights may appear and disappear during driving. Repair is recommended as soon as possible.

Diagnostic Flow Chart

Scan ABS Module
↓ Read Freeze Frame
↓ Road Test
↓ Perform Wiring Wiggle Test
↓ Check Relay
↓ Measure Voltage During Fault
↓ Inspect Connectors
↓ Repair Fault

Oscilloscope Test

An oscilloscope is the best tool for diagnosing DTC C0113 because intermittent faults may not appear with a multimeter. During testing, the waveform should remain stable while the pump is commanded ON.

Normal Pump Signal
__|‾|__|‾|__|‾|__|‾|__

C0113 Intermittent Signal
__|‾|_____|‾|_______|_

Waveform Analysis: Missing pulses indicate intermittent loss of power, ground, connector contact, relay operation, or internal pump motor continuity.

Scanner Live Data

  • ABS Pump Motor Command (ON/OFF)
  • ABS Pump Motor Feedback
  • Battery Voltage
  • ABS Module Supply Voltage
  • Pump Relay Status
  • Wheel Speed Sensors (LF, RF, LR, RR)
  • Brake Pedal Switch Status
  • Brake Pressure (if supported)
  • Traction Control Status
  • Electronic Stability Control Status
  • Freeze Frame Data

Electrical Testing (Typical Values)

Test Item Typical Value
Battery Voltage (Engine OFF) 12.4–12.8 V
Charging Voltage (Engine Running) 13.5–14.8 V
ABS Pump Supply Voltage Within 0.5 V of Battery Voltage
Ground Voltage Drop <0.10 V
Pump Relay Coil Resistance Typically 50–120 Ω
Pump Motor Resistance Refer to manufacturer specification

Professional Diagnostic Tips

  • Perform a wiring wiggle test while monitoring live data.
  • Tap the ABS relay lightly during operation to identify intermittent contacts.
  • Monitor battery voltage during pump activation.
  • Measure voltage directly at the pump connector while the fault occurs.
  • Inspect connector terminals for looseness, corrosion, or heat damage.
  • Look for harness damage near suspension or engine components.
  • If the fault appears only after driving, repeat testing with the system at operating temperature.

Common Repair Mistakes

  • Replacing the ABS pump without checking the relay.
  • Ignoring intermittent wiring faults hidden inside the harness.
  • Skipping voltage drop testing.
  • Replacing the ABS control module before inspecting connectors.
  • Failing to reproduce the fault during a road test.
  • Overlooking water intrusion inside the ABS connector.

Recommended Diagnostic Tools

  • Professional OBD-II Scanner with Active ABS Tests
  • Digital Multimeter (DMM)
  • Two-Channel Oscilloscope
  • Power Probe
  • Battery Load Tester
  • Relay Tester
  • Manufacturer Wiring Diagram

Common Repairs

  • Repair broken or intermittent wiring.
  • Replace loose or corroded connectors.
  • Replace a faulty ABS pump relay.
  • Repair poor ground connections.
  • Replace the ABS pump motor if intermittent failure is confirmed.
  • Replace the ABS hydraulic control module if internal faults are verified.

Estimated Repair Cost

Repair Estimated Cost
Professional Diagnosis $60–$150
ABS Relay Replacement $25–$100
Connector Repair $30–$120
Wiring Harness Repair $80–$350
ABS Pump Motor Replacement $300–$900
ABS Hydraulic Control Unit $700–$2,000+

How to Diagnose DTC C0113 Step by Step

  1. Connect a professional scan tool and verify that DTC C0113 is active or stored.
  2. Save Freeze Frame data before clearing any fault codes.
  3. Check battery voltage and charging system output to eliminate low-voltage conditions.
  4. Inspect the ABS pump fuse and relay for loose terminals, overheating, or intermittent operation.
  5. Use the scan tool's active test to command the ABS pump motor ON while measuring voltage directly at the pump connector.
  6. Perform a wiggle test on the wiring harness and connectors while monitoring live data or the oscilloscope waveform. If the signal drops out when the harness is moved, repair the affected wiring or connector.
  7. Measure voltage drop on both the power and ground circuits during pump operation. Excessive voltage drop indicates high resistance in the circuit.
  8. If proper voltage and ground are present but the signal remains intermittent, inspect or replace the ABS pump motor after confirming the manufacturer's specifications.
  9. Clear all DTCs and perform a road test with several ABS activations to verify that the repair is successful.

Related DTC Codes

  • C0110 – ABS Pump Motor Circuit
  • C0111 – ABS Pump Motor Circuit High
  • C0112 – ABS Pump Motor Circuit Low
  • C0114 – ABS Pump Motor Circuit Performance
  • C0241 – ABS System Performance
  • U0121 – Lost Communication With ABS Control Module

Frequently Asked Questions (FAQ)

Can I drive with DTC C0113?

Yes, but caution is advised. Normal braking remains available, however ABS, Traction Control (TCS), and Electronic Stability Control (ESC) may switch off unexpectedly. Braking performance on slippery roads can be reduced.

What is the most common cause of C0113?

Loose connectors, damaged wiring, corroded terminals, faulty ABS pump relays, and intermittent pump motor failures are the most common causes.

Why is C0113 difficult to diagnose?

Because the fault is intermittent, it may disappear during inspection and return only while driving, when the vehicle vibrates, or after the electrical components reach operating temperature.

Is an oscilloscope necessary?

While a multimeter can identify permanent faults, an oscilloscope is much more effective for capturing intermittent voltage dropouts and missing control pulses associated with C0113.

Which vehicles commonly experience C0113?

C0113 may appear on vehicles equipped with electronically controlled ABS systems from manufacturers such as Chevrolet, GMC, Cadillac, Buick, Ford, Lincoln, Mazda, Toyota, Lexus, Honda, Acura, Nissan, Infiniti, Hyundai, Kia, Subaru, Volkswagen, Audi, BMW, Mercedes-Benz, Volvo, and others. Exact diagnostic procedures vary by manufacturer.

Technical Notes

  • Connector pin assignments and wiring colors vary by manufacturer.
  • Always compare measured values with the factory service manual.
  • After completing repairs, clear all stored DTCs and perform a complete ABS functional road test.
  • If multiple ABS pump circuit codes are present, diagnose the power supply and ground circuits before replacing expensive components.

Conclusion

DTC C0113 indicates an intermittent fault in the ABS pump motor circuit rather than a permanent electrical failure. In many cases, the root cause is a loose connector, damaged wiring, poor ground, failing relay, or an internally worn pump motor. Using a professional scan tool, multimeter, and especially an oscilloscope allows intermittent signal interruptions to be identified accurately, reducing unnecessary parts replacement and restoring reliable ABS, TCS, and ESC operation.

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