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Buick
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1987
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Somerset V6-181 3.0L
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Repair and Diagnosis
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Powertrain Management
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Computers and Control Systems
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Testing and Inspection
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Scan Tool Testing and Procedures
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Function Selector Positions
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RPM - Engine Speed
RPM - Engine Speed
Displays engine RPM as transmitted to ECM from reference sensor. Can be used to detect extra reference pulses caused by electrical interference in reference circuit.