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DTC codes / C00xx · Brakes, steering and suspension / C0070

C0070ABS Hydraulic Pump Motor Circuit Malfunction

C0070 means the antilock braking system (ABS) control module has detected a fault in the electrical circuit that powers the hydraulic pump motor, which is the electric motor that pressurizes brake fluid during ABS operation. The module monitors the motor's voltage and current and sets this code when the circuit does not behave as expected, such as an open circuit, short to ground, or excessive current draw.

SystemChassis
Code typeGeneric (all makes)
SeverityHigh
Fix difficultyProfessional
AreaBrakes, steering and suspension

Symptoms you may notice

  • The ABS warning light is illuminated on the dashboard, often accompanied by the traction control light.
  • The ABS system is disabled, so the wheels can lock during hard braking, especially on slippery surfaces.
  • The brake pedal may feel normal during routine driving, but ABS assist will not activate in an emergency.
  • In some vehicles, a chime or message such as 'Service ABS' appears in the driver information center.
  • Often no symptoms besides the warning light, because the base brakes still function normally.
  • Rarely, the pump motor may run continuously or not at all, leading to a whining noise or a soft pedal.

Common causes, most likely first

  1. A failed ABS pump motor, typically due to worn brushes or internal electrical failure.
  2. Corroded, loose, or damaged wiring and connectors at the pump motor or ABS module.
  3. A blown fuse or fusible link that supplies power to the pump motor circuit.
  4. A faulty ABS control module that is not commanding the motor correctly or has internal circuit damage.
  5. A bad ground connection for the pump motor or ABS module, causing high resistance.
  6. A shorted or open motor winding inside the pump assembly.
  7. In rare cases, a seized pump motor due to contaminated brake fluid or mechanical binding.

How to diagnose and fix it

  1. Check all fuses and relays related to the ABS pump motor circuit, replacing any that are blown or suspect.
  2. Inspect the wiring harness and connectors at the pump motor and ABS module for corrosion, looseness, or damage, and repair as needed.
  3. Perform a voltage drop test on the power and ground circuits to the pump motor to identify excessive resistance.
  4. Use a scan tool to command the ABS pump motor on and off while monitoring current and voltage to confirm the fault.
  5. If the motor does not respond or draws excessive current, remove the pump motor for bench testing or replacement.
  6. If the motor tests good but the code persists, diagnose the ABS control module for internal faults or communication issues.
  7. After repairs, clear the code and perform a road test to verify the ABS system operates correctly and the light stays off.

What the ABS pump motor code really means

  • A common misdiagnosis is replacing the ABS module when the actual fault is a simple corroded ground wire or blown fuse, so always check the basics first.
  • The pump motor may only run during ABS activation or a self-test, so a fault can be intermittent and not appear during a static test.
  • Some vehicles set C0070 when the battery voltage is low or unstable, so a weak battery or charging system issue can mimic a pump motor failure.
  • The ABS pump motor circuit often shares power with other systems, so a fault elsewhere can cause this code without the motor itself being defective.
  • On many cars, the pump motor is not serviceable separately from the hydraulic unit, but aftermarket rebuild services can be a cost-effective alternative to a full unit replacement.

Can I keep driving with C0070?

It is not safe to drive with C0070 because the ABS is disabled, which can increase stopping distances and reduce steering control during hard braking. Avoid driving in wet, icy, or slippery conditions and have the vehicle inspected by a qualified technician as soon as possible.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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