Document: Performance Drop, Error 00575, V6 TDI (Solution)

V6 TDI
Sudden performance drop, error code 00575 (intake manifold pressure) stored in the engine control unit's fault memory.

Cause:
If the engine control unit detects a too low or too high intake manifold pressure (boost pressure), it switches to a limp-home mode, and the engine power is significantly reduced by decreasing the fuel injection amount.

a) If the boost pressure is too low (below the specified limit), it is likely that no vacuum will reach the vacuum chamber of the turbocharger's wastegate actuator, which is responsible for adjusting the guide vanes. It's not the boost pressure control valve itself, but rather intermittently cracked vacuum hoses or torn angled connectors that are most often the cause.

b) If the boost pressure is too high (exceeding the regulatory limit), the most common cause is usually a stiff or jammed variable geometry nozzle mechanism in the turbocharger.


Procedure:
a) Check the entire vacuum hose system for leaks using the manual vacuum pump. Replace any elbows if necessary.
If the vacuum sealing is in order, adjust the guide vanes.
Check the condition of the turbocharger (point b).

b) Disconnect the vacuum hose from the vacuum actuator on the turbocharger and connect the hand vacuum pump to the vacuum actuator. The linkage for the nozzle guide vane adjustment must move freely without sticking. Otherwise, the turbocharger must be removed, and the inspection must be repeated on the removed part.
If the adjustment mechanism is jammed or sticking, the exhaust manifold with its compensator must be removed and carefully inspected. There is a possibility that the exhaust manifold and compensator are corroded internally. Rust particles can detach and become loose.
into the turbine wheel of the turbocharger. As a result, the adjustment mechanism of the guide vanes is damaged.
To avoid repeat damage, replace the turbocharger and exhaust manifold parts.