DP0, AL4

The DP0 / AL4 is a 4-speed electronically controlled automatic transaxle jointly associated with Renault and PSA applications. It is designated DP0 by Renault and AL4 by Peugeot/Citroën and was widely used in front-wheel-drive vehicles with smaller petrol and diesel engines. The transmission uses a torque converter with electronically controlled lock-up, a double epicyclic geartrain and an electro-hydraulic valve body controlling the transmission’s clutches and brakes. Renault's technical documentation confirms the DP0's electronically controlled lock-up system and hydraulic distributor arrangement.

Specification: 4-speed automatic • DP0 / AL4 family • Front-wheel drive • Transverse installation • Torque converter with lock-up clutch • Double epicyclic geartrain • 2 multidisc clutches • 1 multidisc brake and 2 brake bands • Electro-hydraulic valve body • Electronic pressure and shift control • Integrated differential • Multiple final-drive ratios and calibrations according to application.

Commonly fitted to selected Renault Clio, Mégane, Scénic, Laguna and Kangoo, together with Peugeot 206, 306, 307, 406 and 407 and Citroën Xsara, C3, C4 and C5 applications. Exact fitment varies substantially by model, engine and production year. DP0 and AL4 versions also use different manufacturer calibrations and component variations, so the vehicle VIN, transmission identification and individual component/valve-body number should always be confirmed before ordering replacement parts.

Common Faults

Common DP0/AL4 problems include main pressure regulation faults, pressure-modulating solenoid failure, torque-converter lock-up solenoid faults, valve-body wear, overheating and internal clutch/brake wear. Typical symptoms include harsh or delayed gear engagement, incorrect or harsh shifts, slipping, torque-converter lock-up problems and transmission failsafe operation. On AL4-equipped vehicles, transmission faults can also cause the Sport and Snow warning lights to flash. Manufacturer technical information specifically identifies main hydraulic pressure regulation, pressure and lock-up electrovalves, oil-pressure sensing and speed-sensor signals as monitored fault areas.

Common Fault Codes

*Renault and PSA diagnostic systems do not always report identical codes for the same underlying transmission fault, and manufacturer-specific codes can differ from generic EOBD/OBD-II equivalents. Therefore, the vehicle manufacturer, model, year and diagnostic system should be confirmed when interpreting DP0/AL4 fault codes.