C0134 is a manufacturer-specific chassis/ABS diagnostic trouble code. Its exact definition can vary depending on the vehicle manufacturer, ABS system, and model year.
On applicable Chevrolet and other GM vehicles, C0134 means ABS/TCS System Pressure Circuit High. The electronic brake control module (EBCM) has detected a brake-pressure signal that is higher than the expected range or condition for the system.
C0134 does not automatically mean that actual hydraulic brake pressure is dangerously high. The fault may be caused by the pressure sensor signal, wiring, reference voltage, ground, connector, or another problem affecting the ABS/TCS pressure circuit.
C0134 Fault Code Description
C0134 = ABS/TCS System Pressure Circuit High.
Code type: Manufacturer-specific Chassis/ABS code.
Primary system: ABS, Traction Control System (TCS), and brake-pressure monitoring.
The EBCM uses brake-pressure information as part of ABS, traction-control, and vehicle-stability control. When the pressure signal is detected above the expected electrical or calculated range, C0134 may be stored.
What Does C0134 Mean?
C0134 means that the ABS/TCS control system has detected a high condition in the brake-pressure circuit.
The word High can refer to the pressure sensor signal or pressure information monitored by the EBCM. It should not automatically be interpreted as proof of excessive hydraulic brake pressure.
A faulty pressure sensor, shorted signal circuit, incorrect reference voltage, poor ground, connector problem, or an actual brake-pressure condition can contribute to the fault.
C0134 Symptoms
- ABS warning light.
- Traction Control warning light.
- Service Stability System message where equipped.
- Service Traction System message where equipped.
- ABS system may be disabled.
- Traction control may be disabled.
- Vehicle stability control may be disabled.
- Stored ABS/EBCM fault code.
- Possible changes in ABS operation.
On some Chevrolet applications, the EBCM can disable traction control and vehicle stability functions for the ignition cycle when the fault is active.
Common Causes of C0134
- Faulty brake pressure sensor.
- Brake pressure sensor signal too high.
- Signal wire shorted to voltage.
- Open or damaged pressure-sensor circuit.
- Incorrect 5-volt reference voltage.
- Poor sensor ground.
- Corroded or damaged connector.
- High resistance in the pressure-sensor wiring.
- Actual excessive brake-system pressure.
- Brake-pressure system problem.
- EBCM fault.
How to Diagnose C0134
1. Scan the ABS/EBCM
Use a scan tool capable of communicating with the ABS/EBCM. Record C0134 and check for additional ABS, brake-pressure, traction-control, stability-control, or 5-volt reference codes.
2. Check ABS Live Data
Monitor the brake pressure sensor data with the scan tool where supported. Compare the pressure signal with brake pedal operation and vehicle operating conditions.
A pressure reading that remains excessively high, does not respond normally to brake-pedal changes, or is clearly implausible should be investigated.
3. Inspect the Pressure Sensor Connector
Inspect the brake pressure sensor connector for corrosion, water intrusion, loose terminals, damaged pins, or poor terminal tension.
4. Check the 5-Volt Reference
Use the correct Chevrolet wiring diagram to identify the pressure sensor reference circuit. Verify that the reference voltage is within the manufacturer's specified range.
A reference-voltage problem can affect the pressure sensor signal and may produce additional ABS/TCS diagnostic codes.
5. Check the Sensor Ground
Check the pressure sensor ground circuit for excessive resistance, an open circuit, or poor electrical contact.
6. Test the Pressure Signal
Test the pressure sensor signal circuit for a short to voltage, short to ground, open circuit, excessive resistance, or intermittent connection.
Always verify the exact connector pinout and test specifications for the Chevrolet model being diagnosed.
7. Verify Actual Brake Pressure
If the electrical circuit passes testing but the pressure information remains unusually high, the actual hydraulic brake-pressure condition should be investigated according to the manufacturer's procedure.
8. Check the EBCM
If the pressure sensor, wiring, reference voltage, ground, and hydraulic system test correctly, the EBCM may require further diagnosis.
Do not replace the EBCM based only on the presence of C0134.
C0134 Diagnostic Signal Flow
C0134 Chevrolet
On applicable Chevrolet vehicles, C0134 means ABS/TCS System Pressure Circuit High. The EBCM monitors brake-pressure information and can set the code when the pressure signal is higher than the expected range or condition.
Diagnosis should include the brake pressure sensor, 5-volt reference, sensor ground, signal circuit, connector, and actual brake-pressure condition where applicable.
The exact diagnostic procedure varies according to the Chevrolet model, year, ABS system, and EBCM configuration.
Is C0134 Serious?
C0134 should be taken seriously because it can affect ABS, traction control, and vehicle stability functions.
The basic hydraulic brakes may continue to operate, but electronic safety systems may be unavailable while the fault is active.
If the brake pedal feels abnormal, braking performance is reduced, or multiple brake warning lights are illuminated, the vehicle should be diagnosed before continued driving.
Can I Drive With C0134?
Limited driving may be possible if normal braking performance is present and there are no signs of a hydraulic brake problem. However, ABS and stability-control functions may not be available.
The fault should be diagnosed as soon as possible rather than continuing to drive normally with the warning lights active.
C0134 Repair Cost
The repair cost depends on the actual cause of the fault and the Chevrolet model.
- Diagnostic testing: approximately $50–$150+.
- Wiring or connector repair: approximately $50–$300+.
- Pressure sensor-related repair: approximately $100–$500+.
- ABS hydraulic-unit repair: approximately $200–$800+.
- EBCM-related repair or replacement: approximately $500–$1,500+.
These are general estimates only. Actual prices depend on the vehicle, parts availability, labor rates, and the component that has failed.
Common Repair Mistakes
Replacing the Pressure Sensor Immediately
Do not replace the sensor simply because C0134 is stored. Test the signal, reference voltage, ground, connector, and wiring first.
Assuming High Signal Means High Brake Pressure
C0134 can result from an electrical high-signal condition. Actual hydraulic pressure should be evaluated separately when required.
Ignoring the 5-Volt Reference
A reference-voltage problem can affect pressure-sensor operation and may create multiple related ABS/TCS codes.
Replacing the EBCM Without Testing
The EBCM is an expensive component. Verify the sensor and its electrical circuits before condemning the module.
Related Codes
- C0131 – ABS/TCS System Pressure Circuit Malfunction
- C0132 – ABS/TCS System Pressure Circuit Range/Performance
- C0133 – ABS/TCS System Pressure Circuit Low
- C0134 – ABS/TCS System Pressure Circuit High
- C0135 – ABS/TCS System Pressure Circuit Open
- C0136 – Base Brake System Pressure Circuit Malfunction
- C0137 – Base Brake System Pressure Circuit Range/Performance
- C0138 – Base Brake System Pressure Circuit Low
- C0139 – Base Brake System Pressure Circuit High
- C0140 – Base Brake System Pressure Circuit Open
FAQ About C0134
What does C0134 mean?
C0134 means ABS/TCS System Pressure Circuit High on applicable GM/ Chevrolet systems. It indicates that the brake-pressure circuit or pressure-sensor signal is higher than the expected condition.
What causes C0134?
Possible causes include a faulty pressure sensor, signal wire shorted to voltage, incorrect reference voltage, poor ground, damaged wiring, connector problems, actual brake-pressure problems, or an EBCM fault.
What does C0134 mean on Chevrolet?
On applicable Chevrolet vehicles, C0134 means ABS/TCS System Pressure Circuit High. The pressure sensor circuit and related ABS system should be tested using Chevrolet-specific service information.
Does C0134 mean the brake pressure is too high?
Not necessarily. C0134 can indicate a high electrical pressure-sensor signal. The electrical circuit and actual hydraulic pressure should be evaluated separately.
Can a bad pressure sensor cause C0134?
Yes. A faulty pressure sensor can produce an excessively high signal. However, wiring, reference voltage, ground, and connector problems should also be checked.
Can I drive with C0134?
Driving may be possible if the basic braking system operates normally, but ABS, traction control, or stability-control functions may be disabled. The problem should be diagnosed promptly.
Final Result
C0134 is a manufacturer-specific chassis/ABS diagnostic trouble code. On applicable Chevrolet and GM vehicles, it means ABS/TCS System Pressure Circuit High.
The most reliable diagnosis is to scan the ABS/EBCM, inspect the pressure sensor and connector, check the 5-volt reference and ground, test the pressure signal circuit, and verify the actual brake-pressure condition where required.
Always confirm the exact C0134 definition and testing procedure for the specific Chevrolet model, model year, and ABS system before replacing components.