Volvo’s first-generation XC90 with the 163-hp D5 five-cylinder was tuned for smooth family transport and long transmission life, so its Bosch EDC15 control logic imposes gentle torque shaping, modest turbo duty and relaxed rail-pressure ramps. This Stage 1 binary realigns driver-wish and torque-limiter surfaces to translate pedal input into torque more directly, elevates turbo boost demand while honouring factory exhaust-temperature guardrails, and refines rail-pressure targets to keep combustion stable during brisk throttle changes. Injection timing is advanced only across the core 1 700–3 200 rpm band, leaving idle, cold-start and altitude compensations untouched for OEM refinement. EGR flow is trimmed and its diagnostics re-balanced to prevent fault codes while slowing manifold soot build-up. All catalyst, DPF (where fitted), sensor-plausibility and limp-home routines remain fully active; if coolant temperature, turbo speed or intake pressure drift outside specification, the ECU still intervenes exactly as Volvo intended. The result is a more alert throttle, keener mid-range surge and steadier motorway cruising, delivered with zero hardware changes and full emissions self-check integrity.