Function check with diagnosis button Component description General information The EDC system has a diagnosis function which indi- cates whether the system is functioning normally, via a combined button and indication lamp marked DIAGNO- SIS. TWD740VE The EDC system control unit constantly checks sys- tem functions. If a technical problem occurs with the EDC system, or if the system gives unreasonable sig- nals, the indication lamp will start to flash. Reading fault codes If a fault code occurs, the lamp will start to flash. To read the codes, press the DIAGNOSIS button and keep it depressed for at lesst 1 second. A two digit fault code will now be given.
First a number of flashes to indicate the first figure, then a short pause, and then a number of flashes which indicate the second figure. Example: 2 flashes – pause – 4 flashes = fault code 2.4, i.e. a fault in the engine speed sensor or starter relay. Please refer to “EDC fault codes“ on the pages below. DIAGNOSTIC BUTTON When the fault code has stopped flashing, the lamp will go out. Next time the button is pressed, the next fault code will be flashed out. The first fault code will be flashed out again once all fault codes have been read off. NOTE! If the diagnosis has triggered any action (e.g. stopped the engine), the fault code must be erased be- fore the engine can be started again.
Please refer to “Erasing fault codes“ below. Erasing stored fault codes 1. Turn off the system voltage with the ignition switch. 2. Press the DIAGNOSIS button and keep it de- pressed at the same time as you switch the sys- tem voltage on again with the ignition key. Then keep the switch depressed for a further 3 seconds. The fault codes are now erased. Component list* (Only EDC system) 1. 2. Starter motor 3. Alternator 4. Pre-heating relay 5. Starter relay 6. Main relay 7. Stop relay 8. 9. 10. 11. 12. 13. Circuit breaker 14. 2 pcs. 16 pin connectors 15. Test connector 16. Control unit 17. Control solenoid (located inside actuator) 18. Engine speed sensor (located inside actuator) 19.
Control rod position sensor (located inside actuator) 20. Coolant temperature sensor (EDC) 21. Charge air temperature sensor 22. 23. 24. Fuel temperature sensor, located in control unit 25. Charge air temperature sensor, located in control unit * The positions in the illustration of the EDC system are the same as the positions in the wiring diagram and show where on the engine each component is located. 38 15