P0128 on the 2017 Ram Promaster City
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.
Nobody has written a description of this code yet.
| 1806417 | 2022-10-24. Service bulletin. Flash: Powertrain Diagnostic and System Improvements This bulletin involves reprogramming the Powertrain Control Module (PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that the following DTCs has been set:U1424 - Implausible Engine Torque Signal Received. U0402 - Implausible Data Received From TCM. P1DD2-00 - Torque Request Signal From TCM Denied. P0128 - Thermostat Rationality. Enhancement also included:Improved calibrations for catalyst overtemp protection. |
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| 18-121-16 | 2017-11-03. Service bulletin. Flash: Powertrain Diagnostic And System Improvements This bulletin involves reprogramming the Powertrain Control Module (PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that the following Diagnostic Trouble Code (DTC) has been set. P0128 - Thermostat Rationality. |
2 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.