C0137 is a manufacturer-specific chassis/ABS diagnostic trouble code. Its exact definition and diagnostic procedure can vary depending on the vehicle manufacturer, ABS system, and model year.
On applicable GM vehicles, including certain Cadillac applications, C0137 is associated with a Base Brake System Pressure Circuit Range/Performance fault. The ABS/EBCM has detected that the brake-pressure signal is outside the expected range or does not behave correctly under the operating conditions being monitored.
C0137 does not automatically mean that the actual hydraulic brake pressure is incorrect. A pressure sensor problem, wiring fault, connector issue, reference voltage problem, ground fault, or EBCM problem can produce a range/performance condition.
C0137 Fault Code Description
C0137 = Base Brake System Pressure Circuit Range/Performance.
Code type: Manufacturer-specific Chassis/ABS code.
Primary system: Base brake pressure monitoring, ABS/EBCM, and related electronic braking-control functions.
The EBCM monitors brake-pressure information and compares the pressure signal with expected values. If the signal is implausible, outside the expected operating range, or does not respond correctly, C0137 may be stored.
What Does C0137 Mean?
C0137 means that the ABS/EBCM has detected a range or performance problem in the base brake-system pressure circuit.
Unlike a simple open or short-circuit fault, a range/performance code can occur when the circuit is electrically connected but the pressure signal does not match the expected operating behavior.
For example, the signal may remain at an implausible value, respond too slowly, change incorrectly, or disagree with other brake-system information.
Symptoms of C0137
- ABS warning light.
- Brake warning light.
- Traction Control warning light.
- Stability Control warning light where equipped.
- Service ABS message.
- Service Traction System message where equipped.
- ABS functionality may be disabled.
- Traction control may be disabled.
- Stability-control functions may be disabled.
- Stored ABS/EBCM diagnostic trouble code.
The exact symptoms depend on the Cadillac model, ABS module, and the condition causing the code.
Common Causes of C0137
- Faulty brake-pressure sensor.
- Pressure sensor signal out of expected range.
- Incorrect sensor output.
- Damaged pressure-sensor wiring.
- High resistance in the signal circuit.
- Corroded or damaged electrical connector.
- Poor terminal contact.
- Incorrect reference voltage.
- Poor sensor ground.
- Actual hydraulic brake-pressure problem.
- Air or other brake-system condition affecting pressure behavior.
- Internal EBCM fault.
How to Diagnose C0137
1. Scan the ABS/EBCM
Use an ABS-capable scan tool to communicate with the EBCM. Confirm C0137 and check for additional ABS, pressure-sensor, voltage, traction-control, or communication codes.
Additional codes can help determine whether the problem is electrical, sensor-related, or hydraulic.
2. Check Brake Pressure Live Data
Monitor the available brake-pressure data with the scan tool. Observe the pressure value while applying and releasing the brake pedal.
The signal should respond consistently to changes in brake-pedal input. A value that remains fixed, changes erratically, or does not correspond with brake operation requires further testing.
3. Inspect the Pressure Sensor and Connector
Inspect the pressure sensor and connector for corrosion, water intrusion, loose terminals, damaged pins, contamination, or poor terminal tension.
4. Check the Reference Voltage
Use the correct Cadillac/GM wiring diagram to identify the pressure sensor reference-voltage circuit and verify it according to manufacturer specifications.
An incorrect reference voltage can cause an incorrect pressure-sensor signal.
5. Check Sensor Ground
Test the pressure sensor ground circuit for excessive resistance, an open circuit, or poor electrical contact.
6. Test the Pressure Signal Circuit
Check the signal circuit for excessive resistance, intermittent connections, shorts to voltage or ground, and damaged wiring.
Always use the correct connector pinout and specifications for the exact Cadillac model and ABS system.
7. Verify the Hydraulic Brake System
If the electrical circuits and pressure sensor test correctly, inspect the hydraulic brake system for conditions that could cause abnormal pressure behavior.
Do not assume a range/performance code is purely electrical without considering the actual brake-pressure condition.
8. Check the EBCM
If the pressure sensor, wiring, connector, reference voltage, ground, and hydraulic system all test correctly, further EBCM diagnosis may be required.
Do not replace the EBCM based only on the presence of C0137.
C0137 Diagnostic Signal Flow
C0137 Cadillac
On applicable Cadillac vehicles using the relevant GM ABS/EBCM system, C0137 is associated with a Base Brake System Pressure Circuit Range/Performance condition.
The EBCM may set the code when the pressure signal does not remain within the expected operating range or does not respond as expected to brake-system operation.
Diagnosis should include the pressure sensor, wiring, connector, reference voltage, ground, live pressure data, and the hydraulic brake system where required.
Is C0137 Serious?
C0137 should be diagnosed promptly because it can affect ABS, traction-control, or stability-control operation.
The basic hydraulic brakes may continue to operate, but electronic braking and stability functions may be disabled while the fault is active.
If the brake pedal feels abnormal, braking performance changes, or brake-fluid leakage is present, the vehicle should not be driven until the braking system has been inspected.
Can I Drive With C0137?
Limited driving may be possible if the normal braking system operates correctly and there are no signs of hydraulic brake failure.
However, ABS and other electronic braking functions may not operate normally. The fault should be diagnosed as soon as possible.
C0137 Repair Cost
The repair cost depends on the actual cause and the specific Cadillac model.
- Diagnostic testing: approximately $50–$150+.
- Wiring or connector repair: approximately $50–$300+.
- Pressure sensor repair/replacement: approximately $100–$500+.
- Brake hydraulic-system repair: approximately $150–$700+.
- EBCM repair or replacement: approximately $500–$1,500+.
These are general estimates only. Actual repair costs vary according to the Cadillac model, parts availability, labor rates, and failed component.
Common Repair Mistakes
Replacing the Pressure Sensor Immediately
Do not replace the sensor simply because C0137 is stored. The wiring, connector, reference voltage, ground, and live data should be checked first.
Assuming the Hydraulic Pressure Is Wrong
C0137 is a range/performance fault. The electrical pressure signal may be incorrect even when the actual hydraulic system is functioning normally.
Ignoring Live Data
Brake-pressure live data can help determine whether the signal responds correctly to brake-pedal operation and whether the problem is intermittent or persistent.
Replacing the EBCM Too Early
The EBCM should not be replaced until the pressure sensor, wiring, connector, power, ground, and related circuits have been properly tested.
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 C0137
What does C0137 mean?
C0137 means Base Brake System Pressure Circuit Range/Performance on applicable GM ABS systems. It indicates that the pressure signal does not behave within the expected operating range.
What causes C0137?
Possible causes include a faulty pressure sensor, damaged wiring, connector problems, incorrect reference voltage, poor ground, hydraulic brake-system problems, or an EBCM fault.
What does C0137 mean on Cadillac?
On applicable Cadillac vehicles, C0137 is associated with a Base Brake System Pressure Circuit Range/Performance condition. The exact diagnostic procedure depends on the Cadillac model and ABS system.
Does C0137 mean the pressure sensor is bad?
Not necessarily. The sensor, wiring, connector, reference voltage, ground, hydraulic system, and EBCM should all be considered during diagnosis.
Can I drive with C0137?
Basic braking may remain available, but ABS, traction control, or stability-control functions may be disabled. The fault should be diagnosed promptly.
How do I fix C0137?
Start by scanning the ABS/EBCM, checking brake-pressure live data, inspecting the pressure sensor and connector, testing the reference voltage and ground, and checking the signal circuit. Verify the hydraulic system before replacing components.
Final Result
C0137 is a manufacturer-specific chassis/ABS diagnostic trouble code. On applicable GM systems, including certain Cadillac applications, it is associated with a Base Brake System Pressure Circuit Range/Performance condition.
The most reliable diagnosis is to scan the ABS/EBCM, monitor pressure live data, inspect the pressure sensor and connector, verify reference voltage and ground, test the signal circuit, and check the hydraulic brake system where required.
Always confirm the exact C0137 definition, wiring, and diagnostic specifications for the specific Cadillac model and ABS system.