When a Powertrain Control Module (PCM) for a gasoline engine, or an Engine Control Module (ECM) for a diesel engine and the Sentry Key REmote Entry Module (SKREEM) (also known as the Wireless Control Module/WCM) on vehicles equipped with the Sentry Key Immobilizer System (SKIS) are replaced at the same time, perform the following steps in order:Program the new PCM/ECM.Program the new SKREEM/WCM.Replace all ignition keys and program them into the new SKREEM/WCM.The SKIS Secret Key is an ID code that is unique to each SKREEM/WCM. This code is programmed and stored in the SKREEM/WCM, the PCM/ECM, and each ignition key transponder chip. When the PCM/ECM or SKREEM/WCM is replaced, it is necessary to program the Secret Key into the new module using a diagnostic scan tool. Follow the programming steps outlined in the diagnostic scan tool for PCM REPLACED, ECM REPLACED, WCM REPLACED under MISCELLANEOUS FUNCTIONS for the WIRELESS CONTROL MODULE/WCM menu item as appropriate.Be certain to enter the correct country code for the SKREEM/WCM. If the incorrect country code is programmed into the SKREEM, it cannot be changed and the SKREEM must be replaced.In addition, the SKREEM/WCM must be configured for certain optional equipment in the vehicle, including Tire Pressure Monitor (TPM), Remote Keyless Entry (RKE) and Remote Start. Follow the programming steps outlined in the diagnostic scan tool under MISCELLANEOUS FUNCTIONS for the WCM/WIRELESS CONTROL MODULE menu item as appropriate.A replacement SKREEM/WCM is supplied with TPM enabled by default; therefore, if the vehicle is not equipped with TPM, the ElectroMechanical Instrument Cluster (EMIC) will incorrectly learn that the vehicle has TPM after the replacement SKREEM is installed. The TPM indicator in the EMIC will illuminate to show a TPM fault condition after TPM has been disabled in the SKREEM. The EMIC must unlearn TPM to correct this false TPM indication. Follow the programming steps outlined in the diagnostic scan tool for CLEAR LEARNED FEATURES under MISCELLANEOUS FUNCTIONS for the INSTRUMENT CLUSTER menu item as appropriate.On vehicles equipped with a Tire Pressure Monitoring (TPM) system and a full-sized matching spare tire and wheel assembly, when the SKREEM or the spare tire pressure sensor is replaced with a new unit, a diagnostic scan tool MUST be used to run a routine that allows the SKREEM to be programmed with the ID number and location of the spare tire pressure sensor mounted in the wheel of the spare tire. This may be done using a TPM-RKE Analyzer special tool by following the programming steps outlined in the diagnostic scan tool for Program Tire Sensor ID w/TPM Tool under Miscellaneous Functions for the WCM/Wireless Control Module menu item. If a TPM-RKE Analyzer special tool is not available, the spare tire must be dismounted from its wheel to access and note the ID number on the spare tire pressure sensor so that the ID code for that sensor can be programmed into the new SKREEM. Follow the programming steps outlined in the diagnostic scan tool for Learn Spare Tire Sensor ID also found under Miscellaneous Functions for the WCM/Wireless Control Module menu item. (Refer to 22 - TIRES/WHEELS/TIRE PRESSURE MONITORING/SENSOR - INSTALLATION).If the PCM/ECM and the SKREEM/WCM are replaced at the same time, all vehicle ignition keys will need to be replaced and new keys programmed into the new SKREEM/WCM.Programming the PCM/ECM or SKREEM is done using a diagnostic scan tool and a PIN to enter secure access mode. If three attempts are made to enter secure access mode using an incorrect PIN, secure access mode will be locked out for one hour. To exit this lockout mode, turn the ignition to the RUN position for one hour then enter the correct PIN. Be certain that all accessories are turned OFF. Also monitor the battery state and connect a battery charger if necessary.Each ignition key transponder also has a unique ID code that is assigned at the time the key is manufactured. When a key is programmed into the SKREEM/WCM, the transponder ID code is learned by the module and the transponder acquires the unique Secret Key ID code from the SKREEM/WCM. To program ignition keys into the SKREEM/WCM, follow the programming steps outlined in the diagnostic scan tool for PROGRAM IGNITION KEYS OR KEY FOBS under MISCELLANEOUS FUNCTIONS for the WIRELESS CONTROL MODULE/WCM menu item.A maximum of eight keys can be learned to each SKREEM. Once a key is learned to a SKREEM, that key has acquired the Secret Key for that SKREEM and cannot be transferred to any other SKREEM or vehicle.If ignition key programming is unsuccessful, the scan tool will display one of the following error messages:PROGRAMMING NOT ATTEMPTED - The scan tool attempts to read the programmed key status and there are no keys programmed into SKREEM memory.PROGRAMMING KEY FAILED (POSSIBLE USED KEY FROM WRONG VEHICLE) - SKREEM is unable to program an ignition key transponder due to one of the following:The ignition key transponder is ineffective.The ignition key transponder is or has been already programmed to another vehicle.8 KEYS ALREADY LEARNED, PROGRAMMING NOT DONE - The SKREEM transponder ID memory is full.LEARNED KEY IN IGNITION - The ID for the ignition key transponder currently in the ignition lock cylinder is already programmed into SKREEM memory.