Service bulletin 18-023-20

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
Type	Service bulletin
NHTSA id	10175155
Published by NHTSA	2020-05-18
Manufacturer's number	18-023-20
Manufacturer's date	2020-03-19
NHTSA component	ELECTRICAL SYSTEM:SOFTWARE; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ENGINE AND ENGINE COOLING

NHTSA's summary

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 the one or more of the following Diagnostic Trouble Codes (DTCs) have been set:P0780 - Gear Shift Malfunction. P050B - Cold Start Ignition Timing Performance. P06EF - Engine Restart 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. Customers may also comment on one or more of the following:Extended engine crank times or possibly a no start condition(South Korea with Sales Code EDD only). The engine fails to restart while in Engine Stop/Start (ESS) mode. This is usually accompanied withDTC P06EF.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Electrical system, Engine, Transmission and driveline, Automatic transmission, Software, Transmission control module

Trouble codes named

P0456, P050B, P06EF, P0780

Vehicles listed
JEEP CHEROKEE	2019

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
18V739000	2018-10-19. POWER TRAIN:AUTOMATIC TRANSMISSION
18V492000	2018-07-26. POWER TRAIN:AUTOMATIC TRANSMISSION

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
BulletinA	2023-07-31. Service bulletin. Customer Satisfaction Notification ZD7 - Radio Software Update
1806523	2023-07-31. Service bulletin. Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the PCM with the latest available software.
08-229-22	2023-01-17. Service bulletin. Radio Over The Air Software Version Update to 22.66 This bulletin provides information regarding the latest Firmware Over The Air (FOTA) update and provides the service technician an overview of the steps a customer will need to take to complete the update. The radio software will be updated from IR22.64 and IR22.65 to IR22.66. The national launch for the FOTA is expected to begin on January 09, 2023. ? Wi-Fi hotspot connection not working. ? No internet connection message on the phone when trying to connect to a device
1805220	2022-09-26. Service bulletin. Flash: Powertrain Control Module (PCM) Updates 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 have been set:P04FC - Crankcase Ventilation System Performance. P152F - Engine Hood Switch 2 / Engine Hood Switch 1 Correlation(EMEA only equipped with Gas Particulate Filter (GPF))(DTC will set when driving above 72 kph (45 mph). 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. P050B - Cold Start Ignition Timing Performance. P258B - Electric Vacuum Pump Performance. C1252-92 - Vacuum Pump Control Circuit - Performance Or Incorrect Operation. P2B95 - Cold Start Injection Pulse Performance. P062A - Fuel Pump Control Performance. P058C - Battery Monitor Module Temperature Monitoring Performance. P0607 - ECU Internal Performance. Injector performance faults for cylinders 2 - 4 map to DTC for incorrect cylinders. In addition the following software enhancement are included:Software corrects an issue with the wrong cylinder identification if an injector circuit performance fault is set in the PCM:If any of the series of injector control circuit faults are set, please refer to the bullet-pointed list below to determine which injector to address.For reference, the correct injector circuit performance faults are listed below:P02EE - Cylinder 1 Injector Circuit Performance. P02EF - Cylinder 2 Injector Circuit Performance. P02F0 - Cylinder 3 Injector Circuit Performance. P02F1 - Cylinder 4 Injector Circuit Performance. Customers may also experience the following condition:Audible noise from the Low Temperature Radiator (LTR) coolant pump, at low speeds. Abnormal noise from the radiator cooling fan. LTR runs too long after the engine is turned off.
0809921	2022-05-31. Service bulletin. UAQ and UCQ Radio Enhancements This bulletin involves inspecting and if required, updating the radio software level to 39.5 Customers may experience one or more of the following: Intermittent, black radio display screen. Intermittent, radio freezes. Bluetooth® pairing and/or connection issues. Lost radio presets. Radio channels change by itself. SXM icon inoperative. In addition, the following enhancement are included in this update:Enables map updates.
W20 Combo	2021-03-01. Service bulletin. Customer Satisfaction Notification W20 Reprogram Powertrain Control Module
18-063-20 REV. B	2020-12-28. Service bulletin. 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 Diagnostic Trouble Codes (DTCs): P20EE-00 - SCR NOx Catalyst Efficiency Below Threshold Bank 1 Catalyst 1. P24B2-00 - Particulate Matter Sensor Circuit Intermittent. Customers may also describe the following condition: Engine Start/Stop inoperative. Remote start inoperative (South Korea vehicles only). Incorrect vehicle speed reported by the cluster when the driver changes the speed units. Undesirable pedal response in 4-LO mode. Selective Catalytic Reduction (SCR) system fault codes logged at higher vehicle speeds. Alternator load protection at idle. Check Engine Lamp or low battery indicator
18-001-20 REV. B	2020-12-28. Service bulletin. Flash: Powertrain Control Module (PCM) Updates - AN-K4MCA-18-20201001 Refer to China Joint Venture (JV) released document AN-K4MCA-18-20201001, for details on this service action.
S2018000012	2020-12-28. Service bulletin. Check engine lamp on. Fault code P0244- TURBOCHARGER/SUPERCHARGER WASTEGATE SOLENOID "A" RANGE/PERFORMANCE is set in the Powertrain Control Module (PCM a.k.a. ECM) after the turbocharger assembly has been replaced.
18-063-20 REV. B	2020-12-21. Service bulletin. 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 Diagnostic Trouble Codes (DTCs):P20EE-00 - SCR NOx Catalyst Efficiency Below Threshold Bank 1 Catalyst 1. P24B2-00 - Particulate Matter Sensor Circuit Intermittent. Customers may also describe the following condition:Engine Start/Stop inoperative. Remote start inoperative(South Korea vehicles only). Incorrect vehicle speed reported by the cluster when the driver changes the speed units. Undesirable pedal response in 4-LO mode. Selective Catalytic Reduction (SCR) system fault codes logged at higher vehicle speeds. Alternator load protection at idle. Check Engine Lamp or low battery indicator