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International Automotive Technicians Network
Re: 2003 Tahoe TAC Reference Voltage Pulsing
Posted to Technical Discussion Forum on 5/31/2017

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The internal PCM diagnostics watches for shorts between APP 1 and 2 by shorting the APP 2 signal to ground every 156ms for 7.8ms each time. It then watches the APP 1 signal voltage to see if it is be... Login to read more.