1IndexSafety Precautions ... 2Vehicle Service Information ... 3Visual Inspection ...
10working on printed circuit boards.• Cut wire if there is no other pos-sible way to open electrical circuit.4. Connect RED test lead to one sideof di
11Fig. 137. Switch RED and BLACK test leadsand repeat Step 6.8. Test ResultsIf the display showed:• A voltage drop of 0 volts in bothdirections, then
12connect RED test lead to negativeside of primary ignition coil. (referto vehicle service manual for loca-tion of ignition coil)4. Connect BLACK test
13Section 2. Automotive TestingThe digital multimeter is a very usefultool for trouble-shooting automotive elec-trical systems. This section describe
14• If you hear tone - The switch isclosed.• If you don’t hear tone - The switchis open.8. Repeat Step 7 to verify switch op-eration.Good Switch: Ton
15Starting/Charging System TestingThe starting system “turns over” the engine. It consists of the battery, starter motor,starter solenoid and/or relay
164. Disconnect positive (+) batterycable.5. Connect RED test lead to positive(+) battery terminal.6. Connect BLACK test lead to posi-tive (+) battery
17If multimeter overranges, turn multim-eter rotary switch to the 2V DC range.(See Setting the Range on page 6)6. Crank engine until steady readingis
188. Open throttle and Hold enginespeed (RPM) between 1800 and2800 RPM.Hold this speed through Step 11 -Have an assistance help hold speed.9. View rea
19Ignition System TestingThe ignition system is responsible for providing the spark that ignites the fuel in the cylinder.Ignition system components t
2SAFETY GUIDELINESTO PREVENT ACCIDENTS THAT COULD RESULT IN SERIOUS INJURYAND/OR DAMAGE TO YOUR VEHICLE OR TEST EQUIPMENT,CAREFULLY FOLLOW THESE SAFET
2012.Move RED test lead to secondaryignition coil terminal.• Refer to vehicle service manual forlocation of secondary ignition coilterminal.• Verify B
21Ignition System WiresThis test measures the resistanceof spark plug and coil tower wireswhile they are being flexed. Thistest can be used for distri
229VHall Effect sensors are used wheneverthe vehicle computer needs to knowspeed and position of a rotating object.Hall Effect sensors are commonly us
23Magnetic Pick-Up Coils – Reluctance SensorsReluctance sensors are used wheneverthe vehicle computer needs to knowspeed and position of a rotating ob
24Ignition Coil Switching ActionThis test checks to see if the negativeterminal of the primary ignition coil isgetting switched ON and OFF via theigni
25Fuel System TestingThe requirements for lower vehicle emissionshas increased the need for more precise enginefuel control. Auto manufacturers began
26Measuring Fuel Injector ResistanceFuel injectors are similar to solenoids.They contain a coil that is switched ONand OFF by the vehicle computer. Th
27Testing Engine SensorsIn the early 1980’s, computer controls were installed in vehicles to meet FederalGovernment regulations for lower emissions an
28• Connect BLACK test lead to re-maining heater pin.• Turn multimeter rotary switch to200Ω range.• View reading on display.• Compare reading to manuf
291. If engine is HOT let it COOL downbefore proceeding.Make sure all engine and transmis-sion fluids are at outside air tem-perature before proceedin
3Vehicle Service Manual – Sources For ServiceInformationThe following is a list of sources to obtain vehicle service information for your specificvehi
30Position Type SensorsPosition sensors are potentiometers ora type of variable resistor. They areused by the computer to determine po-sition and dire
31• To test intake air tempera-ture sensor see TemperatureType Sensors on page 29.EGR Valve Position• Remove vacuum hose fromEGR valve.• Connect hand
3212.View reading on display.DC Volts Type Sensor:• Verify hand held vacuum pump isat 0 in. of vacuum.• Display reading should be approxi-mately 3V or
338. Operate Sensor.• Start engine and let idle.• Display reading should...- increase in voltage fromKey On Engine OFF for DCtype MAF sensors.- increa
34Electrical SpecificationsDC VoltsRange: 200mV, 2V, 20V, 200VAccuracy : ±(0.5% rdg + 5 dgts)Range: 1000VAccuracy: ±(0.8% rdg + 5 dgts)AC VoltsRange
411Alligator Clip AdaptersSome multimeter tests and measurements are more easily done usingalligator clips instead of test prods. For these tests, pus
5Functions and Display Definitions1. ROTARY SWITCHSwitch is rotated to select a function.2. DC VOLTSThis function is used for measuring DC(Direct Curr
6Setting the RangeTwo of the most commonly asked ques-tions about digital multimeters are Whatdoes Range mean? and How do I knowwhat Range the multime
7Fig. 4Fig. 5value of3.87KΩ. Theactual value ofresistance is3.87KΩ and not4KΩ that wasmeasured inthe 200KΩrange. This isvery importantbecause if thema
8Measuring DC VoltageThis multimeter can be used to measureDC voltages in the range from 0 to 1000V.You can use this multimeter to do any DCvoltage me
9Fig. 9ments, polarity is not important. Thetest leads just have to be connectedacross the component.6. Turn multimeter rotary switch todesired OHM ra
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