Bosch CRS 845 - Pressure Sensors Check

47
Error option 2
The required test pressure during a measurement cannot be
reached despite an intact high-pressure pump.
Cause:
PCV sealing area fails to seal.
a) Intact sealing of PCV
b) Faulty sealing of PCV
1) PCV
2) Sealing edge
3) Feed with fine screen
4) Return
Remedy:
1. Remove PCVs.
2. Check sealing area of high-pressure rail and sealing
edge on PCV for signs of damage (scores, pits,...).
3. Replace a damaged PCV.
! Observe tightening torque when installing PCV.
4. Install PCVs again.
Error option 3
During a pump test, test oil leaks from the PCV.
Cause:
PCV seal in low-pressure area fails to seal.
Remedy:
1. Remove PCVs.
2. Check O-ring and replace if necessary.
! Observe tightening torque when installing PCV.
3. Install PCVs again.
1
2
4
3
458797-16
a)
b)
4.3.2 Check pressure sensors
Two pressure sensors B9 and B10 are installed in the high-
pressure rail to measure the rail pressure.
The output signals of both pressure sensors are evaluated
and displayed in the KMA system software EPS 945 as a
pressure value or as a pressure curve (uniformity of sup-
ply). In addition to this the parallel pressure measurement
(redundancy) is used for mutual monitoring.
Test range
Pressure sen-
sor
Output signal Test range
B9 4 mA-20 mA 0-250 MPa
B10 0,5 V-4,5 V 0-180 MPa
Procedure:
1. Start pump test (CR pump) with pressure measure
-
ment.
2. Ignore error messages.
3. Observe rail pressure during test sequence.
If a pressure is displayed
==> check continuity of connecting cable for B10 pres
-
sure sensor.
==> replace B10 pressure sensor.
If no pressure is displayed
==> check continuity of connecting cable for B9 pres
-
sure sensor.
==> replace B9 pressure sensor.
If the fault is not cleared
==> check control device’s power supply.