C0131
ABS Pressure Sensor Circuit MalfunctionC0131 is a generic OBD-II chassis diagnostic trouble code: ABS Pressure Sensor Circuit Malfunction. It is logged by the engine control unit when the chassis monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What C0131 means
DTC C0131 is set when the EBCM detects that the signal from the ABS hydraulic pressure sensor is outside its expected voltage window, typically below 0.12 V or above 3.2 V, or when the 5 V sensor supply deviates outside 4.5–5.3 V for more than one second. This sensor — which is internal to the Brake Pressure Modulator Valve (BPMV) on most GM full-size trucks and SUVs — monitors master cylinder line pressure so the stability control system can distinguish between driver-commanded braking and an unintended wheel slip event requiring correction.
Because the pressure sensor is physically integrated into the BPMV on affected platforms (Silverado, Sierra, Tahoe, Yukon, Suburban, Escalade), a sensor failure usually means replacing the BPMV assembly or the combined BPMV/EBCM unit. A common installation error is failing to remove the shipping foam from a new BPMV before bolting it in; the foam can hold the solenoids open, cause pressure sensor readings outside range, and set C0131 immediately. Similarly, loose EBCM-to-BPMV mounting hardware can generate micro-vibration that causes intermittent sensor contact faults.
When C0131 is active the EBCM disables traction control and the Vehicle Stability Enhancement System (VSES/StabiliTrak) for the ignition cycle, while ABS itself may remain partially functional. The ABS warning light, traction control light, and a 'Service StabiliTrak' message typically appear simultaneously. The pressure sensor reading in live data is the key diagnostic parameter — a reading that does not change between brake-applied and brake-released states strongly indicates a failed BPMV/sensor.
Common causes
Most-frequently reported root causes when C0131 is logged.
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1
Failed internal ABS hydraulic pressure sensor within the BPMV assembly.
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2
Loose EBCM-to-BPMV mounting bolts causing intermittent electrical contact at the sensor.
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3
Shipping foam or packaging material left inside a replacement BPMV, interfering with pressure sensor reading.
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4
Corrosion or damage at the EBCM-to-BPMV connector affecting the sensor's 5 V supply or signal line.
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5
Faulty EBCM sensor supply voltage regulation (5 V reference out of range).
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6
Moisture intrusion into the BPMV or EBCM connector causing signal voltage errors.
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7
Internal EBCM failure affecting pressure sensor input circuit (less common).
Symptoms drivers notice
How to diagnose C0131
A typical diagnostic flow when this code is present.
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1
Retrieve all ABS/EBCM codes and note accompanying stability control codes; check for related supply voltage codes.
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2
Inspect the EBCM-to-BPMV connector for corrosion, damage, or fluid contamination; clean and reseat if needed.
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3
Verify EBCM mounting bolts are torqued to specification — loose mounting is a documented cause of intermittent C0131.
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4
If a BPMV was recently replaced, confirm all shipping material (foam, caps) was removed before installation.
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5
Use a scan tool to monitor the ABS pressure sensor PID in live data; apply and release the brake pedal — the reading must change proportionally with pedal application.
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6
Measure the 5 V sensor supply and signal return voltage at the EBCM connector using a high-impedance voltmeter; compare to specified range (0.12–3.2 V signal, 4.5–5.3 V supply).
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7
If sensor reading is static or out of range with all electrical connections confirmed good, replace the BPMV assembly; on some platforms the EBCM must also be replaced or reprogrammed as a matched set.
Related chassis codes
Frequently asked questions
Why does C0131 appear right after I replaced the ABS modulator?
The most common reason is that shipping foam or protective caps were not removed from the new BPMV before installation. Remove all packaging material, reinstall the unit, torque the EBCM mounting bolts to specification, and clear the code. Also confirm the EBCM-to-BPMV connector is fully seated.
Is the pressure sensor replaceable separately from the BPMV?
On GM full-size truck platforms (GMT800/GMT900/K2XX generations) the pressure sensor is integrated inside the BPMV and is not serviceable separately. Replacement requires a new or remanufactured BPMV; some modules also require the EBCM to be replaced or reprogrammed as a matched assembly.
Will my ABS still work with C0131 active?
ABS wheel-speed modulation may remain active on some platforms, but the Vehicle Stability Enhancement System (StabiliTrak/ESC) and traction control that depend on pressure sensor input will be disabled. The safest assumption is to treat the vehicle as having compromised active safety systems until the fault is resolved.
Can loose EBCM mounting bolts really set C0131?
Yes — this is a documented, specific cause noted in GM service information. The pressure sensor is internal to the BPMV, and the EBCM bolts directly to it. If the mounting bolts are undertorqued, micro-vibration can cause intermittent electrical contact loss at the sensor interface, setting C0131 without any actual sensor failure.
Disabling C0131 in software
RaceTune can permanently disable C0131 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
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