67
TAMD73, TAMD74
Electronic Diesel Control (EDC) system
(TAMD73P and TAMD74)
The injection pump on the TAMD73P and TAMD74
engines has an electronic governor. The governor
contains an electro-magnet which effects the injection
pump control rod and so the amount of fuel injected
(engine output).
The EDC system measures boost pressure and
charge air temperature and calculates the available air
mass. This determines the amount of fuel injected
(smoke limiter function). To achieve minimal emis-
sions at start the system measures the engine cool-
ant temperature and adapts the amount of fuel re-
quired.
The system also determines the maximum torque
available at the engine speed registered without
risking damaging the engine. To protect the engine at
high engine coolant temperatures, high charge air
temperatures or excessive charge air pressure the
EDC temporarily reduces the amount of fuel (reduced
engine output) until the current values normalize.
The EDC control module also has a diagnostics
system (On-board diagnostics OBD) which assists
users/service technicians to quickly determine the
cause of any malfunctions on the system using the
diagnostic lamp or a diagnostic scan tool (“Diagnostic
Key”).
TAMD73, TAMD74
Note. The components in the figures are numbered
the same as in the engine’s wiring diagram on pages
79, 81, 83, 85 and 87.
3. Generator
4. Starter motor
5. Starter relay
6. Main relay
7. Electronic Diesel Control (EDC) control module
box* (incl. fuel temperature sender, EDC and
turbo pressure sender, EDC)
8. Stop relay
9. Semi-automatic fuses
10. Oil pressure sender, reverse gear
11. Boost pressure sender, (instrument)
12. Oil pressure switch, engine
13. Oil pressure sender, engine
14. Engine coolant temperature (ECT) sender, instrument
19. Charge air temperature sender*
20. Engine coolant temperature (ECT) sender (EDC)*
21. Position sensor, control rod*
22. Engine speed (RPM) sender*
23. Electro-magnetic actuator, EDC*
24. 2-pin connector, data link connector (DLC)*
25. Fuse for EDC system (TAMD74)
* Note. Apply to TAMD73P and TAMD74 engines.
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Summary of Contents for TAMD63L
Page 1: ...INSTRUCTION BOOK TAMD63L P TAMD71B TAMD73P WJ TAMD74C L P ...
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Page 120: ...118 Notes 7740156 Downloaded from www volvopenta com 22 07 2009 00 44 08 ...
Page 121: ...119 Notes 7740156 Downloaded from www volvopenta com 22 07 2009 00 44 08 ...
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Page 124: ...7740156 0 English 6 2000 AB Volvo Penta SE 405 08 Göteborg Sweden www volvopenta com ...