Systems Repair Worksheet s1

Systems Repair Worksheet Chapter 16 Pages 457-500 Name Electrical Diagnosis & Service 70 Points Due Date: 11-13- 12

1. All Electrical problems can be categorized into one of three categories:

______that occur when a circuit is incomplete.

______that occur when a circuit has an unwanted path for current.

______problems that occur when there is unwanted resistance (corrosion).

2. An ______problem prevents a circuit from operating.

A ______to ground reduces resistance and increases current flow to blow the fuse.

A ______to power or “short-to-hot” energizes an unwanted circuit.

High resistance in a path reduces ______flow. (less intensity in bulbs, less speed in motors)

3. Many sensors are fed a ___-volt reference signal. Bad grounds (those with excessive resistance) can result in higher than normal readings back to the PCM from a voltage reference sensor.

4. Wiring diagrams called ______show how a circuit is constructed or arranged.

5. Common electric ______are used in schematic drawings. Some feature color-coded wiring that indicates the color of the wire insulation, but no length or location is depicted.

6. Besides multi-meters, ______wires, test lights and logic probes are used for diagnosis.

7. Non-powered 12-volt test lights are used to check for voltage ______.

8. A ______- ______test light is used to check for continuity.

9. ______are fast reacting meters that measure & display voltage over time.

10. A good ______can do so much more than just read DTC’s! Be sure to use the serial data stream, check TSB’s, use the pattern failure troubleshooter, and all of the modes.

11. Jumper wires with a ______or a circuit breaker can be used to by-pass wires or switches. Do not use a jumper wire to by-pass a consumer or a load. The circuit amps will skyrocket.

12. A computer ______will preserve power to volatile RAMs when the battery is disconnected for service. Note: The SIR system retains its back-up power with a memory saver!

13. A DMM used on computer circuits should have an input ______of 1 MΩ to 10 MΩ.

14. A DMM used on high voltage hybrid vehicles should be ANSI & SCA ______1000 V rated.

15. The auto ______feature on meters detects the proper range & sets the meter to read it. 16. A DMM set to measure volts is connected in ______to a circuit.

17. Voltage ______tests will find excessive resistance that may not be detected with an ohmmeter.

18. Ammeters are connected either in series or using ______pickups to measure current.

19. Ohmmeters are only used on components disconnected from their ______source. (open = OL)

20. The DMM ______test mode (alert) sounds an audible beep when continuity exists.

21. The DMM _____ / _____ is a record function that is useful in capturing intermittent problems.

22. A DMM may also measure ______which is a percentage of circuit on-time.

______normally measured in milliseconds, and ______in hertz.

23. On a lab scope, voltage is shown on the ______axis.

24. On a lab scope, time is shown on the ______axis.

25. Lab scopes can display momentary electrical noise, disturbances, and signal ______.

26. An ______scope is a real-time scope. A ______is a Digital Storage Oscilloscope.

27. Using a DSO, a technician can “ ______” or capture a signal for closer analysis.

28. A multiple ______DSO can display more than one waveform at a time for comparison.

29. Waveform amplitude is shown as ______& waveform frequency is shown as ______.

30. One complete sine wave is a ______. One cycle per second is 1 hertz.

31. A _____ is a DMM that displays voltage, resistance, current & frequency as a waveform graph.

32. Many DSOs and GMMs allow capture & transfer of screens & data to a PC. True False

33. Measuring ______across a fuse or other circuit protection device tells more about its condition than a continuity test.

34. Some systems, like power seat motors use a PTC ______as circuit protection. When the current is high, the resistance of the thermistor increases to decrease current or even stop flow.

35. Both manual switches & automatic switches (pressure switch) can be ______checked, checked for continuity, voltage drop checked or even by-passed with a jumper wire to verify operation.

36. Testing of ______can be done with jumper wires, a volt meter, ohmmeter, or a test light.

37. The best way to test a stepped resistor is with an ohmmeter. True False 38. An unpowered ______can be “sweep tested” with an ohmmeter, preferably a GMM. 39. The best way to check wiring is to check the ______across it.

40. When troubleshooting, verify the complaint, then use the wiring diagrams & do quick ______checks of source & ground to narrow the problem down. Complaint - Cause - Correction

41. When ______probing, using too large of an adapter can deform & loosen terminals.

42. ______probing is necessary when tests like voltage drop need to be done on a “live” circuit.

43. If you test wiring by ______through the insulation, cover the damage to prevent corrosion.

44. For circuit diagnosis a ______diagram is one of the most important sources of information.

45. Connectors and ______are typically numbered to make location easier. (Cxxx Sxxx Gxxx)

46. When tracing a circuit on a schematic, start at the ______that is not working, find its source, its ground, its switch or control, and the circuit protection. Then get busy with the DMM.

47. Printing out the circuit & using a ______to trace it can help avoid confusion.

48. All circuit issues can be boiled down to 1 of 3 things: _____, ______& high ______.

49. A component with a shorted coil of wire will read ______than specs or even zero resistance.

50. A fuse never blows without a reason, probably blown due to a ______to ground.

51. High resistance problems are typically caused by ______that decreases intensity. (amps)

52. Many electrical problems can be traced to faulty wiring or ______.

53. Re-routing wires can result in unwanted ______voltages from electromagnetic fields.

54. All replacement wires should be the ______size or larger than the original, never smaller.

55. ______wires (the proper way to connect wires) joins them by melting a lead & tin alloy and allowing it to flow into the joint. 60/40 rosin core solder of a .032” diameter works well

56. When soldering near heat-sensitive components, use a heat ______to prevent damage.

57. After crimping & soldering a wire splice, place ______shrink tubing over the splice, and warm it with a heat gun to protect the joint from elements that could cause corrosion & shorts.

58. Wire terminal ______and release tools prevent connector damage when unlocking terminals.