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P1815 Diagnostic Trouble Code Discussion for August 2013

TFP Valve Position Switch - Start In Wrong Range


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Trouble Ticket Help Requests for DTC P1815
Help Request Posted
1999 Ford F-150 Lariat 5.4L Poor Idle Quality, MIL Lamp on VIN: 1FTRX18LXX
P1815: 4wd mode select switch short-ground. Check engine light is on for bank 1 only running lean. Bank 2 is not indicated as too lean but LTFT is 19, LTFT on B1 is 25+. No vacuum leaks found. It seems only when vehicle engine cold the problem occurs. At warm idle, the STFT are always 0 +/- 3%. Odometer...
August 15, 2013
1999 Ford F-150 Lariat 5.4L Poor Idle Quality, MIL Lamp on VIN: 1FTRX18LXX
P1815: 4wd mode select switch short-ground. Check engine light is on for bank 1 only running lean. Bank 2 is not indicated as too lean but LTFT is 19, LTFT on B1 is 25+. No vacuum leaks found. It seems only when vehicle engine cold the problem occurs. At warm idle, the STFT are always 0 +/- 3%. Odometer...
August 15, 2013