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Home >> Hummer >> 2008 >> H3 Alpha >> Repair and Diagnosis >> External Pages >> Different car >> Section 191 (Battery, Charging System And Starting System) >> Diagnostic Information and Procedures >> DTC P0621 >> Circuit/System Verification

Circuit/System Verification

WARNING: This page is about a different car, the 2008 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.

Observe the scan tool ECM Generator-L Terminal Circuit Status parameter. The reading should display OK.