(a) List five possible causes of a scan tool failing to interrogate an ECU. * Incorrect software loaded in to scan tools * Fuality multipluge connected or 16 pin connector to scan tools * Incorrect data intered in to scan tools * The ignition switch not switched on * The control unit may be wiped out * The control unit may be in sleeping mode
(b) Discuss the importance of updating scan tools on a regular basis. * The manufacturer requred you to update the scan tools * Using out of date software can wiped out the ecu data * When you contact help line if you don’t have updated software they want talk to you * For safety percaustion reasons

(c) Outline the safety precautions that should be adhered to when carrying out diagnosis on an airbag electrical circuit. * Airbag can developed when you work on ai bag electrical line checking circuit * Working on the streering area checking ciriciut * Proper tools and equipments have to be used working on the circuit * Employee should be follow their duites under safety act
(a) Multiplexing is widely used in modern motor vehicles. List the advantages of this type of wiring compared to conventional methods 1. Less wiring 2. More application can be fiitted possible 3. Lighter wiring diagram for the vehicle 4. Easier faults dagnoisis 5. Cheaper to munfacture 6. 7. . 8. (c) Draw afull wiring diagram of an Electronic Distributorless System (E.D.I.S. used in a four cylinder engine. The diagram should include all the necessary wiring, ignition switch, L.T. and H.T. coils, spark plugs, battery etc. Explain in detail how the system operates. (Label all parts).

b) List any advantages or disadvantages the above system might have over other systems.

(a) Explain the meaning of the term Global Test making