P05DB: Brake Pedal Position Sensor B Circuit/Open

Brake-by-wire and hybrid systems use a dual-channel pedal travel sensor; channel B runs opposite to A at Toyota (3.6–4.4 V at rest, falling when pressed), so a common fault of both channels shows up. It feeds brake assist and regenerative blending; CARB requires inputs used by other diagnoses to be monitored. A channel fault blocks the A/B correlation P05E0 and usually limits brake assist or regeneration. P05DB is the general circuit or open-circuit fault of channel B. Toyota's electronically controlled brake (RAV4 Hybrid 2024–25) reports channel B faults under it; while it is stored, the A/B correlation does not run.

Symptoms

• Brake or regeneration warning light
• Check engine light
• Regeneration or brake assist reduced, pedal feel changed

Most likely causes

• Harness or connector at the pedal sensor (open, contact fault)
• Pedal sensor assembly faulty
• Retrofitted wiring near the pedal (e.g. trailer brake controller)
• Brake or hybrid module

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the pedal and throttle connectors
2. Check the continuity of the wire between the component and the control module.
3. Use live data to confirm that both sensors rise smoothly and consistently
4. Clean the throttle if it has carbon buildup
5. Run the relearn procedure with the scanner if the manufacturer requires it
6. Replace the part identified by the diagnosis

Good to know

• Repair difficulty: hard
• It can trigger limp mode.
• It affects emissions.

What each character of P05DB means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 5: Speed and idle
• DB: Specific fault in that system

Frequently asked questions

Can I keep driving with code P05DB?

Be careful: the car may suddenly lose power. If it goes into limp mode, get off the highway and calmly make your way to a repair shop.

What causes code P05DB?

The most common causes are: harness or connector at the pedal sensor (open, contact fault); pedal sensor assembly faulty; retrofitted wiring near the pedal (e.g. trailer brake controller).

Related codes

• P05DCBrake Pedal Position Sensor B Circuit Range/Performance
• P05DDBrake Pedal Position Sensor B Circuit Low
• P05DEBrake Pedal Position Sensor B Circuit High
• P05DFBrake Pedal Position Sensor B Circuit Intermittent/Erratic
• P057ABrake Pedal Position Sensor A Circuit/Open
• P05E0Brake Pedal Position Sensor A/B Correlation

Sources

• estimateca.mymitchell.com: RM100000002GAKZ
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.