Component Tests and General Diagnostics

19 Load-Throttle Rationality Diagnosis

Load-Throttle Rationality Check

General Description
The Load-Throttle rationality check proofs the consistency between load (measured by Map sensor) and throttle position. The rationality is checked by comparing the excitation of the intake manifold pressure controller or the throttle controller with the corresponding set point.

Subfunction PCV-Diagnosis
The PCV (Positive crankcase ventilation) monitor proofs the plausibility of the output value of the intake manifold model controller during idle speed. The diagnosis is divided in two parts:
- Controller deviation
- Adaption deviation

The controller deviation between two following idle speed phases is compared and if the difference is too high (e.g. a crankcase ventilation pipe is broken or lost), an error symptom is set.
The adaptation deviation checks creaping leakage of the PCV system.

Flowchart PCV-Diagnosis