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P1870 on the 1992 Chevrolet Lumina

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

This code is specific to a manufacturer and is not described here. Its meaning is in the manufacturer's service information.

Bulletins for this model year that name P1870
018802004-07-01. Service bulletin. NO TCC APPLY, MALFUNCTION INDICATOR LAMP (MIL) ON, TCC SURGE, POSSIBLE P0740, P1870, OR 39 AFTER INSTALLATION OF A REMAN (SRTA) 4T60/4T60E. *TT

1 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.