Checking Pressure Sensors - Bosch CRS 845H Instandsetzungsanleitung

en 54 | CRS 845H | Trouble-shooting
Fault situation 3
Test oil emerges at the DRV during the pump test.
Cause:
DRV seal in low-pressure section not tight.
Remedy:
1. Remove DRVs.
2. Check and if necessary replace the O-ring.
!
Heed the tightening torque when fitting the DRV.
!
Always use a new sealing cone when fitting DRVs in
the high-pressure rail.
3. Re-install DRVs.
5.3.2

Checking pressure sensors

The high-pressure rail is fitted with two pressure
sensors B9 and B10 for measuring the rail pressure.
The output signals of the two pressure sensors are
evaluated by the control device and displayed in the
KMA system software EPS 945 as a pressure value or
pressure curve (uniform delivery). Parallel pressure
measurement (redundancy) is also employed as a
means of mutual monitoring and for checking the filter
impact.
B10
1
B9
2
Fig. 21: Installation panel with rail
1 Pressure sensor B10
2 Pressure sensor B9
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1 689 975 229 2011-09-16
The following fault situations may occur:
R
Excessive difference in pressure
Fault situation 1
Excessive difference in pressure between pressure
sensors B9 and B10. A fault message is called up.
Cause:
R
Filter full ==> Replace filter (refer to Section 6.9).
R
Change in calibration values ==> Calibrate pressure
sensors (refer to Section 7).
R
Pressure sensor defective.
Electrical checking:
1. Remove the cover from the control device.
2. Switch on the EPS at the master switch.
3. Remove the connecting cable from the pressure
sensor B9 or B10.
4. Connect a digital multimeter to the connecting cable
(refer to Table) and check the power supply:
Pressure
sensor
B9
B10
5. Use a digital multimeter to check the output voltage
on the trigger PCB LP 320 or LP 472:
Pressure
sensor
B9
B10
i
The output voltage specifications only apply in the
de-pressurized condition.
458857-15_Pal
Pin Set value
1 and 3 5.0 ± 0.01 V
A and C 5.0 ± 0.1 V
LP / connec- Pin Set value
tor
LP 472 / X2 1 and 2 0.5 ± 0.1 V
LP 320 / X12 4 and 6 0.5 ± 0.2 V
Robert Bosch GmbH