# P04FC on the 2018 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 P04FC

- [10229336](https://open.wenmarpro.com/bulletins/10229336), 2023-01-09: 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: P04FC \- Crankcase Ventilation System 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. P061A \- Level 2 Torque Performance. P0507 \- Idle Speed Performance Higher Than Expected. Customers may also describe the following condition:Excessive fan noise when the A/C is on MAX output. Other enhancements included in this update: Electric vacuum pump \(EVP\) update. Fan noise reduction.
- [10226046](https://open.wenmarpro.com/bulletins/10226046), 2022-11-07: 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: P0335 \- Crankshaft Position Sensor Circuit. P0339 \- Crankshaft Position Sensor Intermittent. P2C90 \- Crankcase Ventilation System \- Hose "A" Disconnected. P04FC \- Crankcase Ventilation System 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. P061A \- Level 2 Torque Performance. P0507 \- Idle Speed Performance Higher Than Expected. Customers may also describe the following condition:Excessive fan noise when the A/C is on MAX output. Other enhancements included in this update: Electric vacuum pump \(EVP\) update. Fan noise reduction.
- [10223588](https://open.wenmarpro.com/bulletins/10223588), 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:P2C90 \- Crankcase Ventilation System \- Hose "A" Disconnected\(APAC, EMEA and LATAM Only\). P04FC \- Crankcase Ventilation System Performance\(APAC, EMEA and LATAM Only\). P2453 \- Particulate Filter Pressure Sensor "A" Circuit Range/Performance\(APAC and EMEA only equipped with Gas Particulate Filter \(GPF\). P245F \- Particulate Filter Pressure Sensor "B" Circuit Range/Performance\(APAC and EMEA only equipped with Gas Particulate Filter \(GPF\). P0456 \- EVAP System Small Leak. If DTC P0456 is present use wiTECH Small Leak Verification Test \(SLVT\) to determine if a leak is present in the system. P0171 \- Fuel System 1/1 Lean\(LATAM Only\). P0172 \- Fuel System 1/1 Rich\(LATAM Only\). P0128 \- Thermostat Rationality\(Sales Codes NA1 with NBQ or NB6 Only \- APAC and EMEA Only\). P050B \- Cold Start Ignition Timing Performance\(Sales Codes NA1 with NBQ or NB6 Only \- APAC and EMEA Only\). Customers may comment on one or more of the following:Excessive fan noise when the A/C is on MAX output. Rough idle at engine start up in colder ambient temperatures. Software enhancements also included in this update:Electric Vacuum Pump \(EVP\) update. Fan noise reduction. Low Speed Pre Ignition \(LSPI\) update.
- [10221766](https://open.wenmarpro.com/bulletins/10221766), 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 ofthe following DTCs: P04FC \- Crankcase Ventilation System 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. P061A \- Level 2 Torque Performance. P0507 \- Idle Speed Performance Higher Than Expected. Customers may also describe the following condition:Excessive fan noise when the A/C is on MAX output. Other enhancements included in this update: Electric vacuum pump \(EVP\) update. Fan noise reduction.
- [10194053](https://open.wenmarpro.com/bulletins/10194053), 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\(APAC, EMEA and LATAM Only\). P2C90 \- Crankcase Ventilation System \- Hose "A" Disconnected\(APAC, EMEA and LATAM Only\). P04FC \- Crankcase Ventilation System Performance\(APAC, EMEA and LATAM Only\). P2453 \- Particulate Filter Pressure Sensor "A" Circuit Range/Performance\(APAC and EMEA only equipped with Gas Particulate Filter\(GPF\)\). P245F \- Particulate Filter Pressure Sensor "B" Circuit Range/Performance\(APAC and EMEA only equipped with Gas Particulate Filter \(GPF\)\). P0456 \- EVAP System Small Leak.If DTC P0456 is present use wiTECH Small Leak Verification Test \(SLVT\) to determine if a leak is present in the system. P0171 \- Fuel System 1/1 Lean\(LATAM Only\). P0172 \- Fuel System 1/1 Rich\(LATAM Only\). P0128 \- Thermostat Rationality\(Sales Codes NA1 with NBQ or NB6 Only \- APAC and EMEA Only\). P050B \- Cold Start Ignition Timing Performance\(Sales Codes NA1 with NBQ or NB6 Only \- APAC and EMEA Only\). Customers may comment on one or more of the following:Excessive fan noise when the A/C is on MAX output. Rough idle at engine start up in colder ambient temperatures. The following software enhancements are also included in this update:Electric Vacuum Pump \(EVP\) update. Fan noise reduction. Low Speed Pre Ignition \(LSPI\) update.
- [10181540](https://open.wenmarpro.com/bulletins/10181540), 2020-10-26: Malfunction Indicator Lamp \(MIL\) Illuminated, Diagnostic Trouble Code \(DTC\) P2C90 \- Crankcase Ventilation System \- Hose "A" Disconnected or P04FC \-Crankcase Ventilation Performance
- [10178693](https://open.wenmarpro.com/bulletins/10178693), 2020-08-24: 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: P04FC \- Crankcase Ventilation System 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. P061A \- Level 2 Torque Performance. P0507 \- Idle Speed Performance Higher Than Expected. Customers may also describe the following condition:Excessive fan noise when the A/C is on MAX output. Other enhancements included in this update: Electric vacuum pump \(EVP\) update. Fan noise reduction.
- [10177533](https://open.wenmarpro.com/bulletins/10177533), 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:P2C90 \- Crankcase Ventilation System \- Hose "A" Disconnected\(APAC, EMEA and LATAM Only\). P04FC \- Crankcase Ventilation System Performance\(APAC, EMEA and LATAM Only\). P2453 \- Particulate Filter Pressure Sensor "A" Circuit Range/Performance\(APAC and EMEA only equipped with Gas Particulate Filter \(GPF\). P245F \- Particulate Filter Pressure Sensor "B" Circuit Range/Performance\(APAC and EMEA only equipped with Gas Particulate Filter \(GPF\). P0456 \- EVAP System Small Leak. If DTC P0456 is present use wiTECH Small Leak Verification Test \(SLVT\) to determine if a leak is present in the system. P0171 \- Fuel System 1/1 Lean\(LATAM Only\). P0172 \- Fuel System 1/1 Rich\(LATAM Only\). P0128 \- Thermostat Rationality\(Sales Codes NA1 with NBQ or NB6 Only \- APAC and EMEA Only\). P050B \- Cold Start Ignition Timing Performance\(Sales Codes NA1 with NBQ or NB6 Only \- APAC and EMEA Only\). Customers may comment on one or more of the following:Excessive fan noise when the A/C is on MAX output. Rough idle at engine start up in colder ambient temperatures. Software enhancements also included in this update:Electric Vacuum Pump \(EVP\) update. Fan noise reduction. Low Speed Pre Ignition \(LSPI\) update.