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P1638 Diagnostic Trouble Code Discussion for February 2010

TCM Internal - CAN 1 RAM Performance


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Trouble Ticket Help Requests for DTC P1638
Help Request Posted
2001 Chevrolet Express 3500 5.7L Poor Idle Quality, Misfire, MIL Lamp on VIN: 1GBHG31R61
P1638: Generator 'F' Terminal Circuit Malfunction. ... lacks power, and check engine light is on. Scan for trouble codes. P0335, P1637, P1638. I scoped the CKP signal wire at the PCM. Had a square wave signal. Checked power and ground at CKP sensor. Checked out ok. Perform voltage drop test between PCM and CKP...
February 10, 2010
2001 Chevrolet Express 3500 5.7L Poor Idle Quality, Misfire, MIL Lamp on VIN: 1GBHG31R61
P1638: Generator 'F' Terminal Circuit Malfunction. ... lacks power, and check engine light is on. Scan for trouble codes. P0335, P1637, P1638. I scoped the CKP signal wire at the PCM. Had a square wave signal. Checked power and ground at CKP sensor. Checked out ok. Perform voltage drop test between PCM and CKP...
February 10, 2010