Description
Listed here is OEM part 03G906021AC — a genuine used, tested Engine ECU Control Module belonging to the Volkswagen 03G diesel management series, designed for VAG Group TDI engines across the Golf, Passat, Touran, and related models. This unit was originally built to OEM specification and has been recovered from a written-off vehicle for resale.
This ECU governs the TDI injection system’s core functions: rail pressure regulation, per-cylinder quantity correction, injection pre-pulse and post-pulse strategies, EGR flow management, and variable geometry turbo actuation. Its integrated self-learning algorithms adapt fuel delivery maps over time, maintaining performance as injectors age and wear characteristics change.
Common failure symptoms on vehicles fitted with 03G-series ECUs include unresponsive throttle, sudden entry into limp mode at motorway speeds, fault codes for injection system plausibility stored after every cold start, visible smoke at light acceleration, or a diesel rattle that worsens with load despite serviceable injectors and high-pressure pump.
This part was removed from a written-off vehicle and tested against the 03G906021AC OEM standard before despatch. ECU coding and adaptation using a VAG-compatible interface such as VCDS is required after fitting; installation by a qualified diesel specialist is strongly recommended. Our 14-day return policy covers this used electrical component.
Returns accepted only for genuine faults — faulty on arrival, not as described, or wrong part supplied — requested within 14 days, with all 3 anti-tamper stickers intact. No returns for change of mind, incorrect installation, coding/programming, or buyer compatibility errors; checking compatibility (OEM number, firmware, vehicle) is the buyer’s responsibility. Full policy: https://giantparts.eu/refund-and-returns/
