C0133 is a manufacturer-specific chassis/ABS diagnostic trouble code. Its exact definition can vary depending on the vehicle manufacturer, ABS control module, and model year.
On some Opel/Vauxhall applications equipped with specific TRW ABS systems, C0133 is associated with a return pump circuit malfunction in the ABS hydraulic unit. This application is documented on vehicles such as the Opel Vivaro and certain Opel Movano applications. 1
Because C0133 is not a universally standardized code, the exact meaning should always be confirmed using vehicle-specific service information before replacing any ABS component.
Fault Code Description
C0133 may indicate an ABS return pump circuit malfunction on applicable ABS systems.
Code type: Manufacturer-specific Chassis/ABS code.
Likely system: ABS hydraulic unit, return pump motor, pump circuit, wiring, electrical connector, power supply, ground, or ABS control module.
What Does C0133 Mean?
C0133 means that the ABS control system has detected a problem associated with the return pump circuit. The return pump is part of the hydraulic ABS system and helps manage brake-fluid pressure during ABS operation.
A stored C0133 does not automatically prove that the pump motor itself is defective. Electrical supply problems, wiring faults, connector damage, internal ABS hydraulic-unit faults, or an internal pump motor problem can produce a similar condition.
C0133 on Opel
On some Opel/Vauxhall vehicles using the TRW EBC430EV ABS system, C0133 is listed as a return pump circuit malfunction. Documented examples include certain Opel Vivaro and Opel Movano applications. The exact application depends on the ABS unit and vehicle configuration. 2
For this reason, the ABS module part number and vehicle-specific diagnostic information should be checked before performing electrical or hydraulic tests.
Symptoms of C0133
- ABS warning light.
- Traction control warning light.
- ESP/ESC warning light where equipped.
- ABS system may become unavailable.
- ABS pump may fail to operate correctly.
- Stored ABS control-module fault.
- Possible loss of ABS functionality.
- Possible stability-control system deactivation.
Common Causes of C0133
- Faulty ABS return pump motor.
- Internal ABS hydraulic-unit fault.
- Damaged pump wiring.
- Open circuit in the pump circuit.
- Short circuit in the pump circuit.
- Corroded or damaged electrical connector.
- Poor power supply to the ABS unit.
- Poor ground connection.
- Internal ABS control-module fault.
- Mechanical failure of the pump assembly.
How to Diagnose C0133
1. Scan the ABS Module
Use a scan tool capable of communicating with the ABS/ESP control module. Confirm C0133 and record any additional ABS, hydraulic pressure, pump motor, or communication codes.
Do not diagnose C0133 using only a generic engine-code scanner because the fault is stored in the chassis/ABS system.
2. Check the ABS Power Supply
Check the ABS module power supply, fuses, grounds, and voltage connections according to the vehicle-specific wiring diagram. Low voltage or excessive voltage drop can interfere with ABS pump operation.
3. Inspect the Pump Wiring
Inspect the wiring between the ABS control module and hydraulic pump. Look for broken wires, damaged insulation, corrosion, loose terminals, or water intrusion.
4. Test the Return Pump
If the scan tool supports an ABS actuator test, command the pump on and observe whether it operates correctly. A pump that does not respond should be tested according to the manufacturer's electrical specifications.
5. Check the ABS Hydraulic Unit
If the electrical supply and wiring are correct but the pump does not operate correctly, the ABS hydraulic unit or integrated pump assembly may require further testing or professional repair.
C0133 Diagnostic Signal Flow
Is C0133 Serious?
C0133 should be taken seriously because it may affect ABS operation. The vehicle may continue to have normal basic hydraulic braking, but ABS, traction control, or stability-control functions may be disabled depending on the system and fault condition.
If the ABS or brake warning lights remain illuminated, diagnose the vehicle as soon as possible.
Can I Drive With C0133?
Limited driving may be possible if the normal braking system operates correctly, but the ABS and stability-control functions may not be available.
Avoid driving if there is a change in brake-pedal feel, brake-fluid leakage, reduced braking performance, or multiple brake-system warning lights.
C0133 Repair Cost
The repair cost depends heavily on the vehicle, ABS module, pump assembly, and actual cause of the fault.
- Electrical diagnosis: approximately $50–$150+.
- Wiring or connector repair: approximately $50–$300+.
- ABS pump or hydraulic-unit repair: approximately $200–$600+.
- ABS hydraulic unit replacement: approximately $500–$1,500+.
These are general estimates only. Actual prices vary according to the vehicle, ABS unit, parts availability, labor rates, and whether the module can be repaired or must be replaced.
Common Repair Mistakes
Replacing the ABS Pump Immediately
Do not replace the ABS pump before checking its power supply, ground, wiring, connector, and actuator operation.
Assuming C0133 Has One Universal Definition
C0133 is manufacturer-specific. Its definition and diagnostic procedure can differ between ABS systems. Always confirm the exact code definition for the vehicle being diagnosed.
Using the Wrong Wiring Diagram
ABS pump wiring and connector pinouts can vary between models and ABS module versions. Use the correct wiring diagram for the exact vehicle and ABS unit.
Related ABS Codes
- C0020 – ABS Pump Motor Circuit on applicable systems.
- C0133 – ABS Return Pump Circuit Malfunction on applicable systems.
- C1124 – Pressure Sensor Fault on some applications.
The exact related codes depend on the vehicle manufacturer and ABS control system.
FAQ About C0133
What does C0133 mean?
C0133 is a manufacturer-specific chassis/ABS code. On some Opel/Vauxhall applications, it is associated with a return pump circuit malfunction.
What causes C0133?
Possible causes include an ABS return pump fault, damaged wiring, poor electrical connections, power-supply problems, or an internal ABS hydraulic-unit fault.
What does C0133 mean on Opel?
On some Opel vehicles using specific TRW ABS systems, C0133 is associated with a return pump circuit malfunction. The exact meaning depends on the ABS module and vehicle configuration. 3
Can I drive with C0133?
The vehicle may still have basic braking, but ABS or stability-control functions may be disabled. The fault should be diagnosed before relying on the vehicle for normal driving.
Does C0133 always mean the ABS pump is bad?
No. Wiring, connectors, power supply, ground, the ABS control module, and the hydraulic unit should be tested before replacing the pump.
Final Result
C0133 is a manufacturer-specific chassis/ABS diagnostic code. On certain Opel/Vauxhall applications, it can indicate a return pump circuit malfunction within the ABS hydraulic system. 4
The correct diagnosis should begin with an ABS-capable scan tool, followed by checks of the ABS power supply, ground, wiring, connectors, pump operation, and hydraulic unit according to the vehicle-specific service information.