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P1637 Diagnostic Trouble Code Discussion for January 2010

Generator 'L' Terminal Circuit Malfunction

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Trouble Ticket Help Requests for DTC P1637
Help Request Posted
1999 Pontiac Firebird Formula 5.7L Excessive Emissions, Poor Fuel Economy VIN: 2G2FV22G0X
P1637: Generator 'L' Terminal Circuit Malfunction. I got a good one here for all the GM gurus. This bird will not go into closed loop. Whether at idle, cruise or anywhere in between. O2s show rich at idle and 2500 RPM, they hover about 800mv front and back both banks. Coolant temperature reaches 192F max at id...
January 25, 2010