# P0128 on the 2019 Jeep Wrangler

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.

## Bulletins for this model year that name P0128

- [10224078](https://open.wenmarpro.com/bulletins/10224078), 2022-10-17: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. The customer may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more ofthe following DTCs:P012A \- Turbocharger/Supercharger Inlet Pressure Sensor 1. P012C \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit Low. P012D \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit High. P0607 \- ECU Internal Performance. P06EF \- Engine Restart Performance. P050B \- Cold Start Ignition Timing Performance. P0456 \- EVAP System Small Leak.If DTC P0456 is present use the wiTECH Small Leak Verification Test \(SLVT\) to determine if a leak is present in the system. P0128 \- Thermostat Rationality. P0507 \- Idle Speed Performance Higher Than Expected. Customers may also describe the following condition:Excessive radiator fan noise when the A/C is on MAX output. In addition, the following software enhancements are available:Electric Vacuum Pump \(EVP\) update. Fan noise reduction.
- [10223592](https://open.wenmarpro.com/bulletins/10223592), 2022-10-17: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or more of the following DTCs have been set:P012A \- Turbocharger/Supercharger Inlet Pressure Sensor 1\(APAC, EMEA and LATAM Only\). P012C \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit Low\(APAC, EMEA and LATAM Only\). P012D \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit High\(APAC, EMEA and LATAM Only\). P2C90 \- Crankcase Ventilation System \- Hose "A" Disconnected\(APAC, EMEA and LATAM Only\). P06EF \- Engine Restart Performance. P04FC \- Crankcase Ventilation System Performance. P050B \- Cold Start Ignition Timing Performance. P0128 \- Thermostat Rationality. P0456 \- EVAP System Small Leak. If DTC P0456 is present, use the wiTECH Small Leak Verification Test \(SLVT\) to determine if there is a leak in the system. The following software enhancement is also available in this update:Enable soot retention for vehicles equipped with Gasoline Particulate Filter \(GPF\). Technicians may also experience the following:Unable to read data information from the OBD II connector when using a generic scan tool\(APAC Only\).
- [10221486](https://open.wenmarpro.com/bulletins/10221486), 2022-09-26: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. The customer may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more of the following DTCs: P0335 \- Crankshaft Position Sensor Circuit. P0339 \- Crankshaft Position Sensor Intermittent. P2C90 \- Crankcase Ventilation System \- Hose "A" Disconnected. P061A \- Level 2 Torque Performance. P0607\-00 \- ECU Internal Performance. P2172 \- High Airflow/Vacuum Leak Detected \(Instantaneous Accumulation\). P02EE \- Cylinder 1 Injector Circuit Performance. P02EF \- Cylinder 2 Injector Circuit Performance. P02F0 \- Cylinder 3 Injector Circuit Performance. P02F1 \- Cylinder 4 Injector Circuit Performance. P012A \- Turbocharger/Supercharger Inlet Pressure Sensor 1. P012C \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit Low. P012D \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit High. P0607 \- ECU Internal Performance. P06EF \- Engine Restart Performance. P050B \- Cold Start Ignition Timing Performance. P0456 \- EVAP System Small Leak. If DTC P0456 is present use the wiTECH Small Leak Verification Test \(SLVT\) to determine if a leak is present in the system. P0128 \- Thermostat Rationality. P0507 \- Idle Speed Performance Higher Than Expected. Customers may also describe the following condition:Excessive radiator fan noise when the A/C is on MAX output. In addition, the following software enhancements are available: Electric Vacuum Pump \(EVP\) update. Fan noise reduction.
- [10221194](https://open.wenmarpro.com/bulletins/10221194), 2022-09-26: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or more of the following DTCs have been set:P02EE \- Cylinder 1 Injector Circuit Performance\(APAC, EMEA and LATAM Only\). P02EF \- Cylinder 2 Injector Circuit Performance\(APAC, EMEA and LATAM Only\). P02F0 \- Cylinder 3 Injector Circuit Performance\(APAC, EMEA and LATAM Only\). P02F1 \- Cylinder 4 Injector Circuit Performance\(APAC, EMEA and LATAM Only\). P012A \- Turbocharger/Supercharger Inlet Pressure Sensor 1\(APAC, EMEA and LATAM Only\). P012C \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit Low\(APAC, EMEA and LATAM Only\). P012D \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit High\(APAC, EMEA and LATAM Only\). P2C90 \- Crankcase Ventilation System \- Hose "A" Disconnected\(APAC, EMEA and LATAM Only\). P06EF \- Engine Restart Performance. P04FC \- Crankcase Ventilation System Performance. P050B \- Cold Start Ignition Timing Performance. P0128 \- Thermostat Rationality. P0456 \- EVAP System Small Leak. If DTC P0456 is present, use the wiTECH Small Leak Verification Test \(SLVT\) to determine if there is a leak in the system. The following software enhancement is also available in this update:Enable soot retention for vehicles equipped with Gasoline Particulate Filter \(GPF\). Technicians may also experience the following:Unable to read data information from the OBD II connector when using a generic scan tool\(APAC Only\).
- [10194047](https://open.wenmarpro.com/bulletins/10194047), 2021-05-24: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or more of the following DTCs have been set:P02EE \- Cylinder 1 Injector Circuit Performance\(APAC, EMEA and LATAM Only\). P02EF \- Cylinder 2 Injector Circuit Performance\(APAC, EMEA and LATAM Only\). P02F0 \- Cylinder 3 Injector Circuit Performance\(APAC, EMEA and LATAM Only\). P02F1 \- Cylinder 4 Injector Circuit Performance\(APAC, EMEA and LATAM Only\). P012A \- Turbocharger/Supercharger Inlet Pressure Sensor 1\(APAC, EMEA and LATAM Only\). P012C \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit Low\(APAC, EMEA and LATAM Only\). P012D \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit High\(APAC, EMEA and LATAM Only\). P2C90 \- Crankcase Ventilation System \- Hose "A" Disconnected\(APAC, EMEA and LATAM Only\). P06EF \- Engine Restart Performance. P04FC \- Crankcase Ventilation System Performance. P050B \- Cold Start Ignition Timing Performance. P0128 \- Thermostat Rationality. P0456 \- EVAP System Small Leak. If DTC P0456 is present, use the wiTECH Small Leak Verification Test \(SLVT\) to determine if there is a leak in the system. The following software enhancement is also available in this update:Enable soot retention for vehicles equipped with Gasoline Particulate Filter \(GPF\). Technicians may also experience the following:Unable to read data information from the OBD II connector when using a generic scan tool\(APAC Only\).
- [10184756](https://open.wenmarpro.com/bulletins/10184756), 2020-12-28: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. The customer may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more ofthe following DTCs:P012A \- Turbocharger/Supercharger Inlet Pressure Sensor 1. P012C \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit Low. P012D \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit High. P0607 \- ECU Internal Performance. P06EF \- Engine Restart Performance. P050B \- Cold Start Ignition Timing Performance. P0456 \- EVAP System Small Leak.If DTC P0456 is present use the wiTECH Small Leak Verification Test \(SLVT\) to determine if a leak is present in the system. P0128 \- Thermostat Rationality. P0507 \- Idle Speed Performance Higher Than Expected. Customers may also describe the following condition:Excessive radiator fan noise when the A/C is on MAX output. In addition, the following software enhancements are available:Electric Vacuum Pump \(EVP\) update. Fan noise reduction.
- [10184456](https://open.wenmarpro.com/bulletins/10184456), 2020-12-21: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. The customer may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more ofthe following DTCs:P012A \- Turbocharger/Supercharger Inlet Pressure Sensor 1. P012C \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit Low. P012D \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit High. P0607 \- ECU Internal Performance. P06EF \- Engine Restart Performance. P050B \- Cold Start Ignition Timing Performance. P0456 \- EVAP System Small Leak.If DTC P0456 is present use the wiTECH Small Leak Verification Test \(SLVT\) to determine if a leak is present in the system. P0128 \- Thermostat Rationality. P0507 \- Idle Speed Performance Higher Than Expected. Customers may also describe the following condition:Excessive radiator fan noise when the A/C is on MAX output. In addition, the following software enhancements are available:Electric Vacuum Pump \(EVP\) update. Fan noise reduction.
- [10177537](https://open.wenmarpro.com/bulletins/10177537), 2020-07-27: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or more of the following DTCs have been set:P012A \- Turbocharger/Supercharger Inlet Pressure Sensor 1\(APAC, EMEA and LATAM Only\). P012C \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit Low\(APAC, EMEA and LATAM Only\). P012D \- Turbocharger/Supercharger Inlet Air Pressure Sensor 1 Circuit High\(APAC, EMEA and LATAM Only\). P2C90 \- Crankcase Ventilation System \- Hose "A" Disconnected\(APAC, EMEA and LATAM Only\). P06EF \- Engine Restart Performance. P04FC \- Crankcase Ventilation System Performance. P050B \- Cold Start Ignition Timing Performance. P0128 \- Thermostat Rationality. P0456 \- EVAP System Small Leak. If DTC P0456 is present, use the wiTECH Small Leak Verification Test \(SLVT\) to determine if there is a leak in the system. The following software enhancement is also available in this update:Enable soot retention for vehicles equipped with Gasoline Particulate Filter \(GPF\). Technicians may also experience the following:Unable to read data information from the OBD II connector when using a generic scan tool\(APAC Only\).
- [10175567](https://open.wenmarpro.com/bulletins/10175567), 2020-05-26: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or more of the following DTCs have been set:P06EF \- Engine Restart Performance. P04FC \- Crankcase Ventilation System Performance. P050B \- Cold Start Ignition Timing Performance. P0456 \- EVAP System Small Leak.If DTC P0456 is present use the wiTECH Small Leak Verification Test \(SLVT\) to determine if a leak is present in the system. P0128 \- Thermostat Rationality. The following software enhancement is included:Enable Soot Retention for vehicles equipped with Gasoline Particulate Filter \(GPF\). Customer or technician may also experience the following:Unable to read data information from the OBD II connector when using a generic scan tool\(APAC Only\).
- [10175566](https://open.wenmarpro.com/bulletins/10175566), 2020-05-26: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. The customer may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more of the following DTCs:P06EF \- Engine Restart Performance. P050B \- Cold Start Ignition Timing Performance. P0456 \- EVAP System Small Leak.If DTC P0456 is present use the wiTECH Small Leak Verification Test \(SLVT\) to determine if a leak is present in the system. P0128 \- Thermostat Rationality. P0507 \- Idle Speed Performance Higher Than Expected. Customers may also describe the following condition:Excessive radiator fan noise when the A/C is on MAX output. In addition, the following software enhancements are available:Electric Vacuum Pump \(EVP\) update. Fan noise reduction.