C063A

Code

Generic C — Chassis

Brake Pressure Sensor H Circuit High

Brand: Generic

Type: C — Chassis

Views: UK: 33 EN: 46 RU: 30

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Page language: EN

Causes

Short to battery/ignition voltage on the sensor signal wire
Open/poor ground or reference voltage problems
Damaged wiring or connector (corrosion, bent pins, water intrusion)
Internal failure of the brake pressure sensor
Faulty ABS/hydraulic control module or internal pull‑up circuitry
Incorrect replacement part or wiring modification

Symptoms

ABS warning lamp illuminated
Brake system/traction control warning lamp may also be on
ABS/traction control functionality may be disabled or limited
Possible diagnostic trouble codes for related brake sensors or the hydraulic control unit
No direct change in pedal feel unless ABS is disabled, but ABS may not operate when needed

What to check

Retrieve freeze frame and all stored ABS codes with a scan tool, note conditions
Review live data: brake pressure sensor H voltage/reading and compare to other pressure sensors
Visually inspect wiring, connector boots and sensor location for damage or contamination
Backprobe sensor connector with ignition on (engine off) and measure reference, signal and ground voltages
Check for continuity between signal wire and battery positive (short) with key off
Disconnect the sensor and see if the code persists or changes

Signal parameters

Reference / supply voltage: typically ~5.0 V (varies by vehicle)
Expected sensor signal: ~0.5 V (no/low pressure) rising to ~4.0–4.5 V at high pressure (manufacturer specific)
Fault condition: signal voltage at or near battery voltage (>4.9 V) or stuck at B+
Typical sensor impedance: hundreds to thousands of ohms (refer to OEM spec)

Diagnostic algorithm

Connect a diagnostic scan tool, record all ABS/traction codes and live data. Note if code is current or historical.
Visually inspect the brake pressure sensor H connector, wiring harness, and surrounding area for chafing, corrosion, moisture or rodent damage.
With ignition ON (engine OFF), backprobe the sensor connector: verify reference voltage (about 5 V), sensor signal voltage, and ground continuity to chassis. Record values.
If sensor signal reads near battery voltage, check for short to B+ on the signal wire: turn ignition OFF and measure resistance between signal wire and battery positive. Low resistance suggests a short.
Disconnect the sensor and clear codes. If code clears and does not return, suspect the sensor. If code remains with sensor disconnected, suspect wiring or ABS module.
Wiggle test the harness and connectors while monitoring live data to find intermittent faults.
If wiring and connector check good, swap with a known-good identical sensor (if available) or bench-test sensor per OEM procedure. Replace sensor if it fails.
If sensor and wiring are good, test ABS/hydraulic control module outputs and internal supplies; consult module repair/replace instructions or replace module if internal fault confirmed.
After repairs, clear codes and road test to confirm proper operation and that the code does not return.

Likely causes

Signal wire shorted to B+ (most likely)
Failed brake pressure sensor
Corroded/loose connector or damaged insulation allowing voltage intrusion
ABS/HCU internal electronics fault (less common)

Fault status

⚠️ Status

Brake Pressure Sensor H Circuit High — the ABS module detected a sensor signal voltage above expected range (possible short to battery or sensor/module failure).

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours