P15B3 on 2012-2016 Peugeot 3008 — Brake Fluid Pressure Sensor 'A' Circuit Range/Performance (Honda); Fuel Additive Level Low (Peugeot/Citroën)
1 vehicles · 1 makes · $300-$6,500 repair
How to diagnose and fix P15B3: most-reported vehicles
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Peugeot 3008 · 2012–2016
The 2012–2016 3008 HYbrid4 (2.0 HDi diesel + rear electric motor) suffers hybrid-system faults from two sources: ageing of the Ni-MH high-voltage traction pack under the rear seats, whose poor ventilation accelerates cell imbalance, and an undersized 12V auxiliary battery whose low voltage triggers cascades of spurious fault messages and no-start conditions. Owners report 'Hybrid System Fault' and reduced-power warnings, loss of electric drive (and with it the car's all-wheel-drive capability), and rising fuel consumption when the electric side stops contributing.
Common Symptoms
- 'Hybrid System Fault' or reduced power warning on dash
- Electric drive / EV mode no longer engages
- Noticeably higher fuel consumption
- Car fails to start or shows random multiple warnings
- 4WD mode unavailable (rear axle is electric-only)
How to Fix
Always test and replace the 12V battery first, since many phantom hybrid faults disappear with a healthy auxiliary battery (a trickle charger helps cars used for short trips). Genuine HV pack failures are addressed with refurbished or repaired battery packs from hybrid specialists at a fraction of the new-unit price.
Sources for this issue (7)
- Peugeot 3008 hybrid problem (2013 HYbrid4, hybrid not working) - Peugeot Forumsforum
- 2012 3008 Hybrid recurring engine fault / reduced power - French Car Forumforum
- 3008 Hybrid4 12v Battery Issue - French Car Forumforum
- 3008 Hybrid weird issues fixed - knackered 12V battery - Peugeot Forumsforum
- Most common problems of the Peugeot 3008 Hybrid4 system - Electric Zentrum (battery repair specialist)article
- Peugeot hybrid 3008 electric traction system fault: repair the vehicle! - Peugeot Forumsforum
- Peugeot 3008 Hybrid (2013) fault codes P1A45, U11A0, U13A0 - SpeakEVforum
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P15B3 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P15B3 mean?
P15B3 stands for "Brake Fluid Pressure Sensor 'A' Circuit Range/Performance (Honda); Fuel Additive Level Low (Peugeot/Citroën)." P15B3 is a manufacturer-specific code, and its meaning depends on the brand of vehicle that set it. On some Honda models — most often hybrids, where the powertrain computer reads brake fluid pressure to coordinate regenerative and hydraulic braking — it indicates the brake fluid pressure sensor 'A' signal is out of its expected range, which can light the check-engine or brake-system warning lamps and may change brake-pedal feel or disable regenerative braking. On Peugeot and Citroën diesels, the same code instead refers to the particulate-filter fuel additive (Eolys) system: the computer has calculated that the additive level is below its minimum threshold, usually because the additive tank is nearly empty. Neither version means you must stop immediately, but a brake-pressure-sensor fault on a Honda deserves prompt diagnosis because it affects the braking system, and ignoring a depleted additive on a PSA diesel eventually prevents proper DPF regeneration and can lead to a clogged, expensive-to-replace particulate filter. Because usage genuinely differs between manufacturers, confirm the definition with a make-specific scan tool before replacing parts.
What are the most common causes of P15B3?
The most common causes of P15B3 are: Failed or out-of-spec brake fluid pressure sensor 'A' (Honda, especially hybrid models), Damaged wiring, corroded connector, or poor electrical connection in the brake fluid pressure sensor circuit (Honda), Depleted diesel particulate filter fuel additive (Eolys) tank (Peugeot/Citroën diesel), Faulty additive level sensor, additive pump/injector, or a leak in the fuel additive system (Peugeot/Citroën diesel), Low brake fluid level or hydraulic problems causing implausible pressure readings (Honda), Fault in the ABS modulator or brake/powertrain control module (less common). The specific cause varies by vehicle.
How much does it cost to fix P15B3?
Repair costs for P15B3 range from $300 to $6,500, depending on the vehicle and root cause.
Which vehicles are affected by P15B3?
Au7o has documented P15B3 across 1 vehicle models from 1 manufacturers: Peugeot.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.