V50 L5-2.4L VIN 39 B5244S7 (2005)
Detecting the position of the camshaft in relation to the position of the crankshaft
Each camshaft flank aligns with pre-defined positions on the crankshaft when the camshaft is in its 0 position. These positions on the crankshaft are
called flank reference positions. Each flank is 33°CA before top dead center (BTDC) when the camshaft is in its 0 position (camshaft not deployed), see
illustration (D1-D5).
A: Engine speed (RPM) sensor signal.
B: Camshaft position (CMP) sensor signal, intake. From high to low signal when the teeth on the camshaft pulley leave the camshaft position (CMP)
sensor.
C: Low engine speed (RPM) sensor signal because of the holes in the flywheel/carrier plate.
1: Top dead center (TDC) cylinder 1, 0°CA (84°CA after hole "C" in the flywheel/carrier plate).
2: Top dead center (TDC) cylinder 2, 144°CA.
4: Top dead center (TDC) cylinder 4, 288°CA.
5: Top dead center (TDC) cylinder 5, 432°CA.
3: Top dead center (TDC) cylinder 3, 576°CA.
Regulating the camshaft position
To control the intake camshaft the engine control module (ECM) regulates the infinitely variable camshaft reset valve. The valve controls the flow of
engine oil to the continuous variable valve timing (CVVT) unit which is affected by the oil pressure that builds up. This allows the CVVT unit to change
the position of the camshaft. Also see Control (below) and Design See: Powertrain Management/Computers and Control Systems/Description and
Operation/Engine Control Module (ECM)/Design
When controlling the camshaft position (the engine control module (ECM) controls the camshaft), detection of the camshaft flanks will be offset from
the reference positions on the crankshaft. Angles D1-D5 will increase when the camshaft is controlled.
Hint: The exhaust camshaft signals are the same as those of the intake camshaft. However, the exhaust camshaft flanks are 318°CA before the intake
camshaft flanks.
The engine control module (ECM) is then able to calculate the °CA (crankshaft degrees from top dead center (TDC)) that the intake valve opens and the
exhaust valve closes for each cylinder. This is because the opening and closing angles are fixed and predefined in relation to the camshaft flanks.
The camshaft position relative to the crankshaft position can be read in VIDA.
Control, CVVT unit
