P1381

P1381

Diagnosis information - DME (DFI)

Valve lift control - one bank in wrong lift

NOTE:
- Diagnosis detects that all valves of one bank are stuck in the small or large lift by way of the lambda controller.
- Diagnosis is not able to detect which bank is faulty while the vehicle is moving.
- It is possible to read out which bank is faulty after a short test.
- The engine must continue running for this.

Diagnostic conditions
- Perform a short test
- if a fault occurs during the short test
- after the short test, while the engine is still running
--> Read out 2 actual values:
- LV01_Status, valve lift bank 1 after short test
- LV02_Status, valve lift bank 2 after short test
--> The faulty bank is indicated
[faulty] or [b11111111]
[OK] or [b------]

or, if a short test is not possible:
- Engine oil temperature -11 °C ... 111 °C (12 °F ... 232 °F)
- Small lift:
- Engine speed between 1,000 rpm and 2,000 rpm
- Mass air flow between 150 mg/Stroke and 400 mg/Stroke

- Large lift:
- Engine speed between 2,000 rpm and 4,000 rpm
- Mass air flow > 550 mg/Stroke ... 325 mg/Stroke

Possible fault causes
- Insufficient oil supply for faulty bank
(e.g., due to dirt in oil circuit, ...)
- Greatly differing exhaust backpressure values between the banks
(e.g., due to constricted or blocked opening of an exhaust branch)
- Loose contact or corrosion on connectors or lines
- Solenoid hydraulic valve for valve lift control of faulty bank is faulty
- Incorrectly adjusted timing of the intake or exhaust camshaft of a bank
- An oxygen sensor is aged or faulty