P0489 Buick Exhaust Gas Recirculation Throttle Control Circuit A Circuit Low

P0490 Buick Exhaust Gas Recirculation Throttle Control Circuit A Circuit High

Possible causes
– Faulty Exhaust Gas Recirculation (EGR) Solenoid
– Exhaust Gas Recirculation (EGR) Solenoid harness is open or shorted
– Exhaust Gas Recirculation (EGR) Solenoid circuit poor electrical connection
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0490 Buick Description

The Engine Control Module (ECM) does not detect voltage on the Exhaust Gas Recirculation (EGR) Solenoid circuit.

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