Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / C1045 — Hydraulic residual pressure

C1045 — Hydraulic residual pressure

Detailed page for trouble code C1045.

34,405codes
59brands
11,914generic
22,491specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

C1045

LAND ROVER C — Chassis

Hydraulic residual pressure

Brand: LAND ROVER
Type: C — Chassis
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty hydraulic residual pressure switch or sensor
  • Open/shorted wiring or poor connector at the sensor or ABS valve block
  • Faulty ABS hydraulic modulator / valve block
  • Failed ABS pump or pump relay
  • Loss of brake fluid, internal/external leak or collapsed hose
  • Faulty accumulator or low accumulator charge pressure

Symptoms

  • ABS warning lamp and/or brake warning light illuminated
  • Reduced or altered ABS operation (pulsing/blending may be absent or uncontrolled)
  • Changes in brake pedal feel (soft, spongy, or unusually hard)
  • Longer stopping distances or momentary loss of normal braking modulation
  • ABS pump running continuously or unusually noisy
  • Traction/ESC interventions erratic or disabled

What to check

  • Read and record all stored and pending codes, freeze frame and live data with a capable scan tool
  • Inspect brake fluid level and condition; check master cylinder reservoir cap and sensor
  • Visually inspect brake lines, hoses, calipers, wheel cylinders and ABS valve block for leaks
  • Inspect connectors and wiring to residual pressure sensor and ABS modulator for corrosion, damage, or poor seating
  • Check ABS pump operation (listen for pump activation) and relevant fuses/relays
  • Check for related communication codes (U-codes) indicating module comms issues

Signal parameters

  • Residual pressure switch: typically a binary switch (open/closed) or low-voltage sensor signal; expected logical state changes during test — consult vehicle-specific manual for exact voltages
  • Sensor supply: usually ignition-switched 12V or regulated 5V supply; signal output typically 0–5 V if analogue
  • Continuity/resistance: check switch continuity (closed = near 0 Ω, open = infinite) per factory values
  • ABS pump current draw: should rise when pump is commanded; excessive or no current indicates pump or electrical fault
  • Accumulator pressure (where applicable): consult service spec for charged pressure values — verify with proper hydraulic gauge

Diagnostic algorithm

  1. Connect a professional scan tool, record all codes and live data, check freeze-frame, then clear codes.
  2. Perform a visual inspection: brake fluid level, obvious leaks, wiring and connectors at the residual pressure sensor and ABS unit.
  3. Reproduce fault: with scan tool monitor, cycle ABS pump/valves (if tool supports) and observe residual pressure sensor/switch response.
  4. Backprobe the sensor connector: verify supply voltage, ground and signal while operating the system. Compare to vehicle-specific specs.
  5. Check continuity/resistance of sensor wiring to the ABS module; repair any chafing or corrosion.
  6. If hydraulic pressure data is available, confirm pump builds pressure and that valves open/close as commanded. Use a calibrated brake pressure gauge if required.
  7. Inspect accumulator charge pressure (if equipped) and service/replace or recharge per factory procedure if out of specification.
  8. If an external leak or air is found, repair and properly bleed the system before retesting.
  9. If wiring and hydraulic components test OK, evaluate ABS modulator/module function. Replace the module only after confirming external components and communications are good.
  10. After repairs, clear codes and perform road test with live-data monitoring to confirm the issue is resolved and no new codes appear.

Likely causes

  • Damaged or intermittent residual pressure switch/sensor
  • Corroded/loose connector or damaged wiring to the sensor/module
  • Faulty ABS valve block or pump failing to build/release pressure
  • Brake fluid leak or very low fluid level leading to incorrect pressure readings

Fault status

⚠️ Status
Hydraulic residual pressure fault — ABS/brake module reports residual hydraulic pressure out of expected range. May result in impaired ABS or brake performance. Further diagnostics required to identify electrical, hydraulic or module faults.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0 - 3.0 hours

Similar codes

C1040 C1041 C1046 C1259 C1249 U0121
320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .