P0562

P0562 sets when system voltage at the PCM drops below approximately 10.0 to 11.0 volts for longer than the diagnostic window with the engine running, meaning the charging system is not maintaining the battery. Cheapest-first: start with a battery load test and visual inspection of both cable ends. A battery that fails load test (drops below 9.6V under half-CCA load for 15 seconds) will not hold a charge no matter how good the alternator is. If the battery passes, measure charging voltage at the battery posts with engine at 2000 rpm and all accessories on: less than 13.5V means the alternator is undercharging. Check the alternator's B+ output stud directly; if you see 14.2V at the alternator but only 12.8V at the battery, you have voltage drop in the charge wire (corroded fusible link or bad junction). Also verify the engine ground strap; a corroded chassis ground forces charge current through the throttle cable, which can spike P0562. Expensive misdiagnosis: replacing the alternator when the battery cable is the actual offender, especially on GM trucks where corrosion hides under the cable jacket.

Vehicle-specific patterns: 2007-2014 Chevrolet Silverado, GMC Sierra, Tahoe, and Yukon are the textbook case for hidden battery cable corrosion; the negative cable end corrodes inside the molded insulation at the engine-block bolt, sometimes also at the positive terminal under the protective boot. 2005-2010 Ford Mustang and F-150 develop alternator output stud heat damage where the eyelet loosens and arcs. 2004-2009 Dodge Ram 1500 and 2500 with the TIPM lose alternator field control through the TIPM's PCM driver; replacement TIPMs are part of an extensive recall and TSB list. 2003-2008 Toyota Corolla and Matrix wear out alternator brushes around 120K to 160K miles, presenting as P0562 first under accessory load. Estimated repair: $60 to $720.