- fuel supply;
- amount of fuel injected;
- exhaust gas toxicity reduction system;
- turbocharged;
- cruise control;
- air conditioning compressor.
The CDI control unit checks the input and output signals, checks the probability and history of the occurrence of a malfunction (see figure 5.53, 5.54). If a certain signal is not received from the sensor, its value is used in an emergency manner.
Figure 5.53. Input signals used by the CDI engine control unit:
A2. ABS/ETS control unit,
A4. ETC control unit,
A10. Airbag/ETR control unit,
A15. Glow plugs,
A20. Air conditioning control panel,
A25. DAS control unit,
A53. CDI control unit,
B10. Oil level sensor,
B30. Fuel temperature sensor,
B35. Boost pressure sensor,
B39. Mass air flow meter,
B48. Camshaft position sensor,
B60. Coolant temperature sensor,
B63. Inlet air temperature sensor,
B66. Fuel pressure sensor in the distributor,
B71. Accelerator pedal position sensor,
B73. Crankshaft position sensor,
P15. Instrument cluster,
S105. Clutch pedal position sensor,
S123. Cruise control switch.
Figure 5.54. CDI engine control unit output signals:
A2. ABS/ETS control unit,
A4. ETC control unit,
A15. Glow plugs,
A20. Air conditioning control panel,
A25. DAS control unit,
A53. CDI control unit,
K1. Starter relay,
K6. Power relay,
P11. Diagnostic connector,
P15. Instrument cluster,
Y20. Nozzle 1,
Y21. Nozzle 2,
Y22. Nozzle 3,
Y23. Nozzle 4,
Y73. High pressure fuel pump shut-off valve,
Y74. Distributor pressure control valve,
Y75. Fuel pump fuel cut-off valve,
Y80. Boost pressure vacuum converter,
Y83. Shut-off valve,
Y84. EGR system vacuum converter.
CAN bus
The CDI control unit receives variable information from the ABS/ETS control unit, including information from the wheel speed sensors, brake light switch and ABS/ETS system status.
Article based on data from the website MercedesMan.ru
The ETC control unit transmits data to the CDI control unit such as the P and N positions of the automatic transmission gear selector lever, the engagement of the downshift "kickdown" gear, the engagement of the gears and the lock-up status of the torque converter.
The CDI control unit sends the received information to the instrument cluster and air conditioning control panel, including information on the fuel level in the tank, engine off time, refrigerant pressure and the operating status of the air conditioning compressor.
Removal
1. Disconnect the negative cable from the battery.
2. Remove the lower right instrument panel cover.
3. Remove the right side deflector 1 (see figure 5.55).
Figure 5.55. Control unit of the electronic fuel injection system CDI:
1. Side deflector,
A19. Control unit of closed electrical system,
A4. ETC control unit,
A53. CDI control unit,
A53.1. Wiring connector 1 CDI control unit,
A53.2. Wiring connector 2 CDI control unit,
A53.3. Wiring connector 3 CDI control unit,
A53.4. Wiring connector 4 CDI control unit,
A53.5. Wiring connector 5 of the CDI control unit.
4. Disconnect connectors A53.1, A53.2 and A53.3 from the CDI control unit A53.
5. Disconnect the wiring connector from the ETC A4 control unit.
6. Disconnect the CDI control unit from the bracket. Press the CDI control unit up and remove it from the bracket. The CDI control unit can be installed between the A19 closed system control unit and the ETC A4 control unit.
Installation
1. Installation is carried out in the reverse order of removal.