P1635 BUICK -

Question

The engine idles at 2000. Where is this 5 volt thing located ?

Answer 1

There are 3 circuit connected together: The Air Condition (A/C) Pressure sensor, the Manifold Absolute Pressure (MAP) sensor and the Engine Gas Recirculation (EGR) valve. If one of the sensor circuit is internally damage or the circuit is shorted you will get the P1635 code. Start by checking the connectors for the previously mention components.

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P1635 BUICK - 5 Volt Reference 1 Circuit

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