# P0456 on the 2016 Ram 4500

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 P0456

- [10236933](https://open.wenmarpro.com/bulletins/10236933), 2023-05-30: wiTECH Small Leak Verification Test \(SLVT\) \- P0456\-EVAP SYSTEM SMALL LEAK
- [10220071](https://open.wenmarpro.com/bulletins/10220071), 2022-09-15: wiTECH Small Leak Verification Test \(SLVT\) \- P0456\-EVAP SYSTEM SMALL LEAK
- [10169219](https://open.wenmarpro.com/bulletins/10169219), 2019-12-16: wiTECH Small Leak Verification Test \(SLVT\) \- P0456\-EVAP SYSTEM SMALL LEAK
- [10160012](https://open.wenmarpro.com/bulletins/10160012), 2019-05-20: Flash: 6.4L Powertrain Diagnostic And System Enhancements This bulletin involves reprogramming the Powertrain Control Module \(PCM\) with the latest available software. NOTE: This bulletin fixes all vehicles listed and also contains an optional software path for situations where the customer is specifically complaining of a Drone Noise, Shudder, Pulsation, or Vibration under light throttle applications while vehicle is operating in MDS/ECO mode \(optional software available for D2 \& DJ vehicles\). There will be two separate software options displayed on the wiTECH flash tab. The software file released for this condition contains the verbiage OPTIONAL. The other file is the standard software that does not contain improvements for the Drone/Shudder concern. If for some reason the customer finds this shudder improvement objectionable, the PCM software may be returned/reflashed to the standard version. Both software versions will address the remaining conditions noted in the bulletin. A small number of customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find the following Diagnostic Trouble Code \(DTC\): ? P0456 \- Evap System Small Leak. ? P3402 \- Cylinder 1 Deactivation Control Performance. ? P3426 \- Cylinder 4 Deactivation Control Performance. ? P3442 \- Cylinder 6 Deactivation Control Performance. ? P3450 \- Cylinder 7 Deactivation Control Performance. ? P2610 \- PCM Internal Engine Off Timer Performance set in the PCM memory. In addition to the DTC listed above, the software update will improve: Improved Cruise Control Acceleration mode. ? Improved Multi Displacement System operation. 6\-Speed Automatic 66RFE transmission \(Sales Code DFP\). ? Multi Displacement System function improved while in PTO stationary mode. 6\-Speed Auto Aisin AS66RC transmission \(Sales Code DF3\). ? Potential small improvement in fuel economy at higher altitudes. ? Potential improvement in high altitude eng
- [10121651](https://open.wenmarpro.com/bulletins/10121651), 2017-11-03: Flash: 6.4L Powertrain Diagnostic And System Enhancements This bulletin involves reprogramming the Powertrain Control Module \(PCM\) with the latest available software. A small number of customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find the following DTCs: · \*\*P0335 \- Crankshaft Position Sensor Circuit. · P2610 \- PCM Internal Engine Off Timer Performance.\*\* · P0456 \- EVAP System Small Leak. · P3402 \- Cylinder 1 Deactivation Control Performance. · P3426 \- Cylinder 4 Deactivation Control Performance. · P3442 \- Cylinder 6 Deactivation Control Performance. · P3450 \- Cylinder 7 Deactivation Control Performance. · P2610 \- PCM Internal Engine Off Timer Performance set in the PCM memory. In addition to the DTCs listed above, the software update will improve: · \*\*Correct an issue related to rounding of the cruise control set speed displayed in the cluster. · Brake Throttle Override calibration has changed to be less sensitive. · Throttle Body supplier change has caused a widening of the minimum and maximum voltage limits · Correct a software issue with oil pressure light function at key\-up. · Correct a software issue related to idle timer. · Correct a software issue with inconsistent engine RPM increments/decrements with operator idle speed.\(DD/DF/DP ONLY\).\*\* · Improved Cruise Control Acceleration mode. · Improved Multi Displacement System operation 6\-Speed Automatic 66RFE transmission \(Sales Code DFP\). · Multi Displacement System function improved while in PTO stationary mode. 6\-Speed Auto Aisin AS66RC transmission \(Sales Code DF3\). · Potential small improvement in fuel economy at higher altitudes. · Potential improvement in high altitude engine idle RPM stability. · EGR monitor status function.