Code Défaut P1525 Renault May 2026

On F9Q 1.9 dCi engines (Laguna II, Espace IV), the same code appears for an entirely different reason:

Parameter: Brake Track 1 (Voltage) – Brake released: 11.8V Parameter: Brake Track 2 (Voltage) – Brake released: 0.2V (Pedal pressed): Track 1 drops to 0.1V, Track 2 rises to 11.7V **Fault trigger condition:** Transition time between states > 80 ms on one track while the other has already switched. This explains intermittent faults: The pedal feels normal. The brake lights work (they use a separate circuit, often a mechanical switch on the pedal arm). Yet the ECU sees a 120 ms "both tracks low" window during a quick pedal release. P1525 logs. code défaut p1525 renault

Example from Renault DDT2000 diagnostic logs: On F9Q 1

In generic OBD-II, P1525 often points to "Throttle Actuator Control (TAC) System – Idle Speed Monitor." , this code takes on a completely different, specific meaning: Fault in the Brake Pedal Position Sensor Plausibility / Turbo Pressure Regulation Implausibility. Yet the ECU sees a 120 ms "both

In 2003–2008 Renault models (Megane II, Scenic II, Laguna II), the brake pedal sensor assembly was placed , subject to dust, humidity from wet shoes, and mechanical vibration. The internal wiper contact design was later revised (Part number changed from 82 00 645 443 to 82 00 890 737).

1. The Generic vs. Manufacturer-Specific Reality