DCMI Explaination Engine Manual complete.pdf
- 1. XLRTT85MC0G018829 26-5-2024 DMCI electronic unit (D965) The electronic unit is mounted on the cylinder block with rubber insulating bushes (3). The electronic unit has three 62-pin connectors. Input signals from various sensors are continuously processed and compared with data stored in various maps (tables) in the electronic unit. Actuators are energised on the basis of the signals received and the maps. An earth cable (2) connects the housing (1) of the electronic unit directly to the engine block. This earth connection is required for the internal components that protect against external radio waves. The electronic unit incorporates an atmospheric pressure sensor and a temperature sensor. The housing of the electronic unit contains an air vent (4) for the atmospheric pressure sensor. An identification sticker (5) is attached to the electronic unit. Effect of atmospheric pressure on the system: the quantity of fuel injected when driving at high altitudes (low air pressure). If atmospheric pressure is low (in mountainous areas), the air is thinner. When the air is thinner, density is lower. The electronic unit uses this information to control the turbocharger pressure and adjust the quantity of fuel to be injected. Effect of the internal temperature sensor on the system: none. The internal temperature sensor measures the temperature of the electronic unit. If the temperature becomes too high, a fault code is stored. The system does not take any further action on the basis of this information. Calibration The performance of pump units and injectors may differ slightly from one another as a result of small production tolerances. These small production differences are compensated for during production with calibration to optimise the engine output, exhaust gas emissions and handling characteristics. A calibration code is used to program the pump units and injectors into the electronic unit individually. The electronic unit modifies control of the pump units and injectors on the basis of these calibration codes. M025853 - 23/01/2009 i400785 1 5 2 3 4
- 2. Accelerator Pedal Sensor (F672) The accelerator pedal sensor (F672) is mounted on the accelerator pedal. The sensor (2) consists of a potentiometer and a switch. Potentiometer The output signal (B33) from the potentiometer is a voltage that has a fixed relation to the position of the accelerator pedal. Therefore the driver determines the output of the accelerator pedal. The potentiometer signal is the basis for determining the quantity of fuel to be injected. The potentiometer has a supply voltage (B34) and earth (B37) via the electronic unit. Idling switch B34 D965 B33 B37 B38 B41 Parallel to the potentiometer, the idling switch is also operated by depressing the accelerator pedal. The idling switch is open in the no load position and is closed when the accelerator pedal is operated. The switch is required for the emergency function, when the potentiometer signal is absent. This emergency function allows the vehicle to be driven to a safe place or a workshop if there is no potentiometer signal. One side of the switch is connected to earth (B38) via the electronic unit. The positive side (B41) is connected to earth with the switch. Kick-down The kick-down (1) under the accelerator pedal only acts to form a mechanical resistance when the accelerator pedal is depressed. The electronic unit detects the kick-down status because the value of the output signal from the potentiometer is higher than at full load. The kick-down is used, for instance, to disengage temporarily variable vehicle speed limiting so that an automatic or automated gearbox can shift down (to accelerate). C A B D F F672 2 Effect of potentiometer output signal on the system: the basis for determining the quantity of fuel to be injected. engine brake disengaging and engaging conditions; disengaging conditions for Downhill Speed Control; CAN message on accelerator pedal position, via V-CAN1 (AS Tronic, AGC- A) and V-CAN2 (EBS-2, VIC, body builder module); CAN message on kick-down position active, via V-CAN1 (AS Tronic, AGC- A). Effect of idling switch output signal on the system: emergency function if the potentiometer does not work; engine brake disengaging and engaging conditions; disengaging conditions for Downhill Speed Control; CAN message on idling switch active, via V-CAN1 (AS Tronic) and V-CAN2 (VIC, ZF intarder, EBS-2, DIP-4, body builder module). 1 1 Kick-down switch 2 Accelerator pedal sensor i400694 M025854 - 26/08/20 4677 4679 4678 4166 4680
- 3. XLRTT85MC0G018829 26-5-2024 This information applies exclusively to the entered chassis number or the selected vehicle series. Please take into account that this information may change daily. Therefore the provided information is only valid on 26-5-2024. You cannot derive any rights from the information provided with respect to vehicles and/or components of another series, with another chassis number and/or of another date Coolant temperature sensor (F566) The coolant temperature sensor emits a signal that indicates the temperature of the coolant and, therefore, indirectly the engine temperature. The sensor used is of the NTC (Negative Temperature Coefficient) type. The higher the temperature, the lower the resistance of the sensor. Effect of output signal on the system: calculation of glowing time; calculation of the quantity of fuel to be injected and the injection timing; calculation of actuation of the electronically controlled fan clutch; limiting of engine torque when the temperature is too high; CAN message on engine temperature, via V-CAN2 to VIC for display on the instrument panel; limitation of the maximum engine speed when the engine is cold. M025855 - 26/08/2013 i 400440
- 4. Crankshaft sensor (F552) The crankshaft sensor (F552) registers the engine speed and is used to 1 determine the injection timing. Together with the camshaft sensor, the crankshaft 2 sensor is responsible for synchronisation when starting the engine. If there is no 3 camshaft signal, the crankshaft signal is used for cylinder detection. The crankshaft sensor (A) is mounted on the flywheel housing (B). It is an inductive sensor, which consists of a magnet (C), a metal core (D) and a coil (E). Inductive means that the sensor can generate an alternating voltage signal independently with a changing magnetic field. The pattern of holes in the flywheel (F) means that the sensor can generate a specific alternating signal. The pattern consists of three segments each with 18 holes and an area with two holes missing (G). Each segment is used for calculations on two specific C cylinders (1/6, 2/5 and 3/4). D The sensor has three connections. Pins 1 and 2 are responsible for the signal. E Pin 2 is the signal connection and pin 1 is the earth connection. Pin 3 is connected to the shield around the signal wires and to the earth connection (pin 1). This prevents outside signals affecting the engine speed signal. G I400731 1 Electrical connection, earth 2 Electrical connection, signal 3 Electrical connection, shield A Crankshaft sensor B Flywheel housing C Magnet D Metal core E Coil F Flywheel G Hole pattern
- 5. The most powerful changes in the magnetic field of the sensor take place when the pattern of holes (1) in the flywheel changes from a hole to a tooth and vice versa. A sine-wave alternating voltage (2) is generated as a result of this 1 changing magnetic field. As a hole approaches, the crankshaft sensor signal must be at the maximum positive value. The crankshaft sensor signal must drop to the maximum negative value as the end of the hole approaches. This is determined by the sensor connections to the electronic unit. The electronic unit converts this sine-wave alternating voltage signal to a digital signal (3), which it uses to carry out calculations. 2 3 E500606
- 6. 1 2 I400732 Sine-wave signals (2) can be measured using an oscilloscope with the engine running, using the pattern of holes in the flywheel (1). Each hole in a segment (b) generates a sine-wave pulse. When the area with the two holes missing (a and c) passes underneath the crankshaft sensor, the pulse pattern is interrupted. This enables the sensor to detect the end of the segment. Effect of output signal on the system: synchronisation during starting; injection timing calculation; registration of engine speed; cylinder detection if there is no camshaft signal; a CAN message on the engine speed to other vehicle systems via V-CAN1 (AS Tronic, EAS) and V-CAN2 (VIC, ZF intarder, ABS-D,ABS-E4, EBS-2, DIP-4, ECAS-4, body builder module); an engine speed output signal (EMAS, cabin lead-through connector). M025857 - 26/08/2013 This information applies exclusively to the entered chassis number or the selected vehicle series. Please take into account that this information may change daily. Therefore the provided information is only valid on 26-5-2024. You cannot derive any rights from the information provided with respect to vehicles and/or components of another series, with another chassis number and/or of another date
- 7. Camshaft sensor (F558) Together with the crankshaft sensor, the camshaft sensor (F558) is responsible for synchronization when starting the engine. The signal also provides the information relating to cylinder detection. If the crankshaft sensor (F552) is defective, the camshaft signal acts as a reserve signal for registering the engine speed and determining the correct injection timing The camshaft sensor (A) is mounted on the flywheel housing (B). It is an 1 inductive sensor, which consists of a magnet (C), a metal core (D) and a coil (E). 2 Inductive means that the sensor can generate an alternating voltage signal 3 independently with a changing magnetic field. The sensor can generate a specific alternating signal by means of a tooth pattern on the pulse wheel (F). The sensor has three connections. Pins 1 and 2 are responsible for the signal. Pin 1 is the signal connection and pin 2 is the earth connection. Pin 3 is connected to the shield around the signal wires and to the earth connection (pin 2). This prevents outside signals affecting the signal. C D E F I400761 1 Electrical connection, signal 2 Electrical connection, earth 3 Electrical connection, shield A Camshaft sensor B Flywheel housing C Magnet D Metal core E Coil F Pulse wheel
- 8. The most powerful changes in the magnetic field of the sensor take place when the tooth pattern (1) on the pulse wheel changes from a tooth to a hole and vice 1 versa. A sine-wave alternating voltage (2) is generated as a result of this changing magnetic field. As a tooth approaches, the camshaft sensor signal must be at the maximum positive value. The camshaft sensor signal must drop to the maximum negative value as the end of the tooth approaches. This is determined by the sensor connections to the electronic unit. The electronic unit converts this sine-wave alternating voltage signal to a digital signal (3), which it uses to carry out calculations. 2 3 6 2 4 s 1 5 3 i400839 a b I400762
- 9. Sine-wave signals (2) can be measured using an oscilloscope with the engine running, using the tooth pattern on the pulse wheel (1). Each tooth, and therefore pulse, corresponds to a specific cylinder. The additional tooth before the cylinder 1 tooth is the synchronisation tooth (S). The pulse this generates is required to realise the synchronisation procedure together with the crankshaft sensor signal. Effect of output signal on the system: synchronisation during starting; cylinder detection; calculation of injection timing if the crankshaft sensor is defective; registration of the engine speed if the crankshaft sensor is defective; a CAN message on the engine speed to other vehicle systems if the crankshaft sensor is faulty via V-CAN1 (AS Tronic, EAS) and V-CAN2 (VIC, ZF intarder, ABS-D, ABS-E4, EBS-2, DIP-4, ECAS-4, body builder module); an engine speed output signal if the crankshaft sensor is faulty (EMAS, cabin lead-through connector). M025858 - 26/08/2013
- 10. 11 10 9 8 7 Wastegate valve (B368) The wastegate valve controls opening and closing of the wastegate on the turbocharger. The wastegate valve air supply (6) comes directly from the air supply unit, circuit 4 (approximately 10 bar). The valve adjusts this pressure to a control pressure (9) for the diaphragm housing of the wastegate. The wastegate valve checks the output pressure with an internal pressure sensor (11). The internal electronics (2) compare the signal issued by the internal pressure sensor with the signal from the electronic unit. The internal electronics energise the coil (3) with a duty cycle (PWM) signal. If the required pressure differs from the actual pressure, the internal electronics modify the duty cycle. There is a hole in the valve (5) to connect the outlet (9) to the vent (7). This hole is used to leak air and therefore obtain more stable wastegate valve operation. i401328 1 2 3 4 5 6 i400741
- 11. 1 Electrical connection 2 Internal electronics 3 Coil 4 Core 5 Valve 6 Air connection, supply (1) 7 Vent (3) 8 Piston 9 Air connection, wastegate (2) control pressure 10 Housing 11 Internal pressure sensor Rest position and bleed position In the rest position or during bleeding, the coil (3) is not energised. The piston (8) and the valve (5) are pushed up by the force of the spring. This also pushes up the metal core (4). The outlet (9) is now connected to the air vent (7). 3 4 5 8 i400745-2
- 12. Constant pressure When the coil (3) is energised, the metal core (4) is pushed down. The valve (5) closes off the opening to the air vent in the piston (8). The pressure in the outlet (9) now stays constant. 3 4 5 8 i400746-2 Pressure increase If the coil (3) remains activated longer, the valve (5) pushes the piston (8) further down. The air supply opening (6) to the outlet (9) is now released. This increases the output pressure. 3 5 6 8 i400747-2
- 13. Pump unit (B131, B132, B133, B134, B135, B136) The pump unit supplies fuel to the injector. The pump unit consists of a metal housing (3) in which an electrical coil (2) opens a valve (1). In the rest position, the valve (1) is pushed up by a spring (4). The electrical connection (8) is screwed onto the outside of the pump unit. The roller tappet (6) rotates around the camshaft and actuates the plunger (5), which builds up the fuel pressure. The fuel enters the pump unit via the fuel gallery opening (A). This opening goes into the fuel supply gallery in the engine block. The fuel leaves the pump unit in the direction of the injector via a delivery valve (7). The fuel pipe is fitted to the injector supply connection (C). Leak-off and lubricating fuel from the plunger is fed back to the return gallery in the engine block via the return opening (B). A C 7 1 2 3 4 8 5 B 6 i400714-2
- 14. A. Fuel gallery opening B. Return opening C. Injector inlet connection 1. Lid 2. Coil 3. Pump unit housing 4. Spring 5. Plunger 6. Roller tappet 7. Delivery valve 8. Electrical connection Electrical control The pump unit is activated with a voltage of approximately 50 V. This voltage is the discharge from a capacitor in the DMCI electronic unit. The current increases rapidly because of this relatively high voltage. As a result, the valve in the pump unit opens quickly. This is the pull phase. If the current were not limited, it would become too high and damage the coil in the pump unit. The increase in current is limited by switching to pulsating control of approximately 24 V after discharging the capacitor. This is the hold phase. The current now remains high enough to hold the valve open. The length of the pull phase stays practically the same under all circumstances. The length of the hold phase varies depending on the calculations carried out by the electronic unit When the pump unit is deactivated, a negative induction peak is created by switching off the current through the pump unit coil. U (V) 60 40 20 0
- 15. Operation The fuel is supplied to the pump unit via the gallery in the engine block and flows towards the delivery chamber above the plunger. The delivery chamber now fills. i400715-3
- 16. The pressure does not build up immediately when the plunger is pushed up by the camshaft. The fuel can still flow back to the fuel gallery via the supply opening. i400716-3
- 17. When the coil is activated, the valve is pulled down and the opening to the fuel gallery closes. Not until now does the plunger start building up pressure. The fuel cannot flow back to the gallery and must now flow towards the injector outlet via the delivery valve. Fuel is now supplied to the injector. i400717-3
- 18. When the electronic unit deactivates the coil, the valve is pushed up again by the spring and the opening to the fuel gallery is released again. This stops the supply of fuel to the injector. i400715-3
- 19. Every pump unit is calibrated after production to compensate for any inaccuracies and differences in production. There is a four-letter calibration code on the housing of the electrical connections. This code is also programmed in the electronic unit so that the unit can optimise controls for fuel injection. If the pump unit is replaced or moved, make sure that the calibration code is programmed (again) into the electronic unit using DAVIE. i400771 M025860 - 23/01/2009 This information applies exclusively to the entered chassis number or the selected vehicle series. Please take into account that this information may change daily. Therefore the provided information is only valid on 26-5-2024. You cannot derive any rights from the information provided with respect to vehicles and/or components of another series, with another chassis number and/or of another date 0209 FMFM 1621297 SN 03030209 00000FMFM
- 20. A 8 9 10 11 B 12 13 14 Injector B421, B422, B423, B424, B425, B426 The pump unit supplies fuel to the injector. The injector consists essentially of two parts. The top part is a metal housing (1), to which the electrical connector (7) is attached. The coil (10) and spring (9) that open and close the valve (11) 7 are also in the housing. The bottom part bears the closest resemblance to a conventional injector. The valve (11) and its guide are in this part, the nozzle holder (4). Below this are the plunger (12) and spring (13) and, finally, the nozzle (6), with the injector needle (14) inside. The washer (5) is under the nozzle holder. The fuel enters the injector via the supply (A), in which the bar filter (8) is pressed. The return fuel leaves the injector via the opening (B) and flows into 1 the cylinder head return duct. 2 3 4 5 6
- 21. A. Fuel supply B. Return opening 1. Injector body 2. O-ring 3. O-ring 4. Nozzle holder 5. Washer 6. Nozzle 7. Electrical connection 8. Bar filter 9. Spring 10. Coil 11. Valve 12. Plunger 13. Plunger spring 14. Injector needle Electrical control The injector is activated with a voltage of approximately 50 V. This voltage is the discharge from a capacitor in the DMCI electronic unit. The current increases rapidly because of this relatively high voltage. As a result, the valve in the injector opens quickly. This is the pull phase. If the current were not limited, it would become too high and damage the coil in the injector. The increase in current is limited by switching to pulsating control of approximately 24 V after discharging the capacitor. This is the hold phase. The current now remains high enough to hold the valve open. The length of the pull phase stays practically the same under all circumstances. The length of the hold phase varies depending on the calculations carried out by the electronic unit. When the injector is deactivated, a negative induction peak is created by switching off the current through the injector coil. U (V) 60 40 20 0
- 22. Operation In the rest position, the valve is pushed down by the spring above the valve. The opening to the return is now closed. Even though fuel is now supplied to the injector, this does not mean that it immediately starts injecting. The same fuel pressure that must lift the injector needle also pushes down the plunger - along with the plunger spring. The injector needle cannot yet be lifted. i400723-2
- 23. When the electronic unit activates the coil, the valve is pulled in against the pressure of the spring and the opening to the return is released. As a result, the pressure above the plunger decreases. The fuel pressure under the injector needle now overcomes the pressure of the spring above the plunger. The injector needle is lifted and fuel is injected. To stop injection, the fuel supply pressure to the injector is decreased by deactivating the pump unit. The injector is only deactivated once the fuel pressure is low enough. This is to allow the plunger spring to close the injector needle quickly. i400724-2 Every injector is calibrated during production to compensate for any inaccuracies and differences in production. There is a six-letter calibration code on the housing of the electrical connections. This code is also programmed in the electronic unit so that the unit can optimise controls for fuel injection. As a result, the electronic unit can make sure that the injection timing and the quantity of fuel injected do not differ. If the injector is replaced or moved, make sure that the calibration code is programmed (again) into the electronic unit using DAVIE. i400772
- 24. An electronically controlled fan clutch is used for accurate control of the fan speed. The electronically controlled fan clutch checks and controls the fan speed to make sure that the flow of cooling air through the cooling system is sufficient to keep the coolant temperature and/or intake air temperature within certain limits. The coil (4) fitted to the drive shaft (5) with bearings generates a magnetic field. Depending on the variables stated above the duty cycle to the coil (4) is modified. This causes changes in the magnetic field and the valve (2) is attracted either more or less. Control of the fan clutch depends on various factors: coolant temperature intake air temperature vehicle speed engine speed fan speed intarder activation internal slip of the fan clutch (slip heat protection) The fan clutch consists of a stator (1) and rotor (3), which is fixed to the drive shaft (5). It also includes the supply chamber (6) for the silicone fluid. The working area is located between the stator (1) and the rotor (3). The fan is fitted to the stator (1) and rotates freely around the drive shaft (5). The speed of the fan is sensed by an internal Hall sensor and a pulse disc. This sensor sends a signal to the DMCI electronic unit. The electronic unit uses this signal to check the internal slip of the fan and the response to controls. 1 Stator 2 Valve 3 Rotor 4 Coil 5 Drive shaft 6 Supply chamber 7 Working area 1 2 3 4 5 6 7 i401012
- 25. The valve (2) is now in the original position. The filler opening is now released and the return opening is closed. The quantity of silicon fluid through the working area (7) between the stator (1) and the rotor (3) increases because of this. The friction in the working area between the stator (1) and the rotor (3) increases. The difference in rotating speed (slip) between the stator (1) and the rotor (3) decreases. The fan speed is increased because of this. The fan speed approaches or exceeds the engine speed depending on the transmission between the crankshaft and the fan drive. This therefore means that in the event of failed actuation of the fan clutch the fan turns at maximum speed. Not actuated Fan clutch actuated 1 2 3 4 5 6 7 i401012
- 26. If a duty cycle activates the coil (4), the valve (2) is attracted by the resulting magnetism. The valve (2) closes the filler opening and at the same time the return opening opens. The silicon fluid now flows from the working area (7) between the stator (1) and the rotor (3) to the supply chamber (6). Less silicon fluid in the working area means more slip between the stator (1) and the rotor (3). The fan speed decreases. Actuated Duty cycle high means decreasing fan speed. Duty cycle low means increasing fan speed. M025862 - 23/01/2009 1 2 3 4 5 6 7 i401013
- 27. XLRTT85MC0G018829 26-5-2024 This information applies exclusively to the entered chassis number or the selected vehicle series. Please take into account that this information may change daily. Therefore the provided information is only valid on 26-5-2024. You cannot derive any rights from the information provided with respect to vehicles and/or components of another series, with another chassis number and/or of another date Oil level sensor (F673) The operation of the engine oil level sensor (F673) is based on resistance measurement. When the contact is activated, a current is sent through the sensor from the DMCI unit for a specific period of time. Applying this current briefly in this way, makes sure that the sensor is properly warmed up. The quantity of oil in the sump influences the resistance value when the oil level is measured. M025864 - 23/01/2009 E501146
- 28. XLRTT85MC0G018829 26-5-2024 Sensor, boost pressure (F802) This sensor measures the air pressure in the inlet manifold and the temperature of this air. The electronic unit uses this data to calculate the quantity of air drawn in. The quantity of intake air must be known to calculate the quantity of injected fuel to prevent smoke. The charge pressure is also directly related to the turbocharger pressure control. The wastegate valve is actuated depending on this signal. Effect of pressure signal on the system: calculation for smoke limitation; calculation of wastegate control; protection of turbocharger; CAN message to VIC for the charge boost pressure display on the main display of the DIP. M025823 - 08/07/2009 1 3 2 4 A
- 29. XLRTT85MC0G018829 26-5-2024 This information applies exclusively to the entered chassis number or the selected vehicle series. Please take into account that this information may change daily. Therefore the provided information is only valid on 26-5-2024. You cannot derive any rights from the information provided with respect to vehicles and/or components of another series, with another chassis number and/or of another date Boost temperature sensor (F804) The boost temperature sensor (F804) measures the air temperature in the inlet manifold. The boost temperature sensor used is of the NTC (Negative Temperature Coefficient) type. The higher the temperature, the lower the resistance of the sensor. Effect of temperature signal on the system: calculation of glowing time; correction of wastegate control; correction of the smoke limiting system; exhaust gas temperature limitation by limiting the maximum quantity of fuel to be injected. M025824 - 26/08/2013
- 30. XLRTT85MC0G018829 26-5-2024 Fuel pressure sensor (F801) This sensor measures the fuel pressure in the fuel gallery. The sensor is located in the middle of the fuel gallery between the cylinder 3 pump unit and the cylinder 4 pump unit. In this way, the measured values for fuel pressure represent the whole fuel gallery best. The fuel pressure sensor is a piezo-capacitive sensor. The higher the pressure, the higher the voltage signal. Effect of pressure signal on the system: limitation of the maximum engine speed when the pressure is too high or too low. M025825 - 23/01/2009 1 3 2 4 A
- 31. XLRTT85MC0G018829 26-5-2024 Fuel temperature sensor (F803) The fuel temperature sensor measures the fuel temperature in the fuel gallery. The sensor is located in the middle of the fuel gallery between the cylinder 3 pump unit and the cylinder 4 pump unit. In this way, the measured values for fuel temperature represent the whole fuel gallery best. The fuel temperature sensor is of the NTC (Negative Temperature Coefficient) type. The higher the temperature, the lower the resistance. Effect of temperature signal on the system: correction of quantity of fuel to be injected; calculation of glowing time; limitation of the maximum engine speed when the temperature is too high or too low. M025826 - 26/08/2013 2 3 1 4
- 32. XLRTT85MC0G018829 26-5-2024 This information applies exclusively to the entered chassis number or the selected vehicle series. Please take into account that this information may change daily. Therefore the provided information is only valid on 26-5-2024. You cannot derive any rights from the information provided with respect to vehicles and/or components of another series, with another chassis number and/or of another date Oil temperature sensor (F808) The engine oil temperature sensor used is of the NTC (Negative Temperature Coefficient) type. The higher the temperature, the lower the resistance of the sensor. Effect of temperature signal on the system: a CAN message to VIC to actuate oil temperature warning on the DIP main display when the engine oil temperature is too high. M025817 - 26/08/2013 i 400440
- 33. XLRTT85MC0G018829 26-5-2024 This information applies exclusively to the entered chassis number or the selected vehicle series. Please take into account that this information may change daily. Therefore the provided information is only valid on 26-5-2024. You cannot derive any rights from the information provided with respect to vehicles and/or components of another series, with another chassis number and/or of another date Oil pressure sensor (F810) The engine oil pressure sensor is a piezo-capacitive sensor. The higher the pressure, the higher the voltage signal. The engine oil pressure is measured via an opening in the sensor. The higher the pressure, the higher the voltage signal. Effect of pressure signal on the system: a CAN message to VIC to actuate oil pressure indicator light and warning on the DIP main display when the engine oil pressure is too low. M025827 - 23/01/2009 1 4 2 3 A i401505