General Motors Co. recalled another 1.6 million vehicles Friday, expanding an earlier ignition-switch recall and disclosing other problems with newer cars and recently launched pickup trucks and sport utilities.

GM has now recalled about 4.8 million vehicles world-wide since early February, when it announced the first recall of 2005-2007 Chevrolet Cobalts and several related small cars to fix an ignition-switch defect linked to 13…