Audi A5 2.0 TDI Turbo

From CAHA to CNHA, CZJA or DTP: which new turbo for the 2.0 TDI A5, depending on its power output?

The answer comes down to two points: power output alone is not enough — it is the engine code stamped on the block that determines the exact reference. The A5 2.0 TDI covers four distinct power outputs — 170, 177, 190 hp (40 TDI) and 190 hp — each with a different turbo, all available here as new parts.

Four power outputs, four reference families

The code CAHA corresponds to the 170 hp version. The CGLC fits the 177 hp, including the quattro variant. The 190 hp badged 40 TDI covers codes DTP and DTPA. Finally, the other 190 hp — without the 40 TDI badge — spans six codes: CNHA, CZJA, DDAA, DESA, DETA, DFHA; these codes share the same reference family (04L253… series) but are not interchangeable with those from the other power outputs. Checking the code before ordering avoids receiving a part that is geometrically similar but incompatible.

Symptoms and causes to identify before replacement

On these TDI blocks, turbo failure typically shows up as blue-grey smoke under acceleration, an abnormal whistling noise, or a loss of power under load. The most common causes are insufficient lubrication at start-up — degraded oil or a partially blocked feed circuit — and upstream fouling linked to the EGR circuit or the diesel particulate filter. Fitting a new turbo without addressing the root cause will lead to another failure: cleaning the oil circuit and checking the lubrication return are prerequisites before fitting.