Repair Boost: Flash Reprogramming
As computer technology continues its adaptation in the modern automobile, the number of electronic control modules (ECU) also increases. The powertrain control module (PCM) was the first module, controlling all aspects of engine operation. If we take a look at the 2017 models, most of the system functions are computer-controlled, from the navigation system to sliding passenger doors on the minivans (in fact, the all-new Chrysler Pacifica is equipped with 35 ECUs)!
In the pre-computer days, when a problem occurred on a car, it was usually a mechanical problem. The only electrical problems were related to the simple ignition or the basic accessory system (lights and radio).
Today, that is no longer the case. A transmission problem is not necessarily a mechanical problem, it could be the result of the control system (as vacuum-controlled automatic transmissions disappeared a while ago). Additionally, problems with the closing of the sliding door on the 2012 minivan, which will be examined later, is not a mechanical problem; rather, it is related to the power sliding door module (PSDM).
Fortunately, ECU problems can be corrected, by utilizing flash reprogramming.
Flash Reprogramming Basics
Flash reprogramming is simple as it is just updating the ECU software instead of replacing the entire module that has the current software. This procedure involves downloading the new software from FCA US LLC, via a WiFi connection, into the specific module that has the problem. There is one system available for this task, wiTECH 2 (WiFi-based).
The updated software is downloaded to the ECU via a secure connection between a Micropod II VCI device and the laptop, tablet or smartphone running the wiTECH 2.0 application. The Micropod II (see Figure 1) connection device is plugged into the OBD port under the dashboard as shown in Figure 2.
As seen in Figure 1, this Micropod II has been marked 2.0 ONLY by the tech. This is common practice. If the device is not marked, the tech doesn’t know how it is configured. If it is configured for wiTECH 1, it will not work, as wiTECH 1 is no longer supported.
Flash Reprogramming a Module
To perform the flash programming procedure, install the Micropod II in the OBD port, then make the WiFi connection using a tablet (this is the preferred device). Install a battery charger to ensure that battery voltage does not drop below 13.2 volts. Do not allow the charging voltage to climb above 13.5 during the flash process. If the flash process is interrupted via a physical Micropod II device disconnect from the vehicle, the flash process must be re-started if it was not previously completed successfully. If the flash process is interrupted but the Micropod II device was not disconnected, the flash process will continue in the background (Micropod II LED will blink a red light) until completed successfully. Upon completion, a reconnect to the wiTECH application will be possible.
On the tablet, the Vehicle Selection screen will be displayed. It will show the year, make, model, engine, and VIN of the vehicle being repaired. At the top of screen, the number of DTCs (Diagnostic Trouble Codes) and available fl ashes will be displayed. Using the tabs at the top of the screen (Topology/All DTCs/All Flashes/Recalls/RRTs), select the desired action item. For example, if Topology is selected, an organizational chart is displayed that shows all the control modules and how each module is connected to each other.
In Figure 3, a section of the Topology page is shown. A small lightning bolt in a green circle is next to the square labeled PCM. This indicates that a flash is available, but non-essential from the powertrain control module (PCM). If the lightning bolt circle were blue, the flash would be essential (required).
When the All Flashes action item is selected, the screen will display all the flashes that are available for all the control modules on the vehicle. Click on the applicable fl ash and follow the prompts to perform the flash procedure.
When the PCM is replaced, it is necessary to flash the module to enter the vehicle information. In order to perform this task, a secret key code, associated with the new module, is required. To program the new PCM, connect the battery charger and the scan tool. The ignition key should be in the RUN position. On the scan tool screen, select the following in this order: ECU View, WIN Wireless Control, Miscellaneous Functions, PCM Replaced. Enter the key code, then verify the correct vehicle information. Cycle the ignition key after the successful routine completion.
Flashing in the Aftermarket
The information required to flash program comes directly from FCA US LLC. If you operate an independent repair facility, you must obtain a subscription to FCA US LLC’s TechAuthority to access this information.
Also, PCM flash reprogramming and Diagnostic Routine failures have been known to be caused by aftermarket equipment that’s been installed on the vehicle being repaired. If the flash reprogramming session fails repeatedly, check the vehicle for aftermarket equipment. This would include radios, remote start systems, alarm systems, lights and tuners. If aftermarket equipment is found on the vehicle, check for an inline fuse or module that can be disconnected easily, then restart the flash reprogramming session.
Flash Reprogramming Example
Service Bulletin 08-059-12 describes re-fl ashing the power sliding door module (PSDM) with updated software. This is required due to a problem with the power sliding door (the door does not close). As mentioned earlier, this is an example of a mechanical problem that is caused by a software issue, not a mechanical one. This bulletin applies to Town & Country/Caravan models built between 2011-2013 (prior to October 13, 2012).
Vehicle owners might experience that the power sliding door is stuck in the open position and the motor is making a clicking noise. There are no stored Diagnostic Trouble Codes (DTCs) in the PSDM. This happens when the PSDM loses the position counts. The sliding door can still be closed using the inside or outside door handle. Flashing the PSDM will correct this condition.
Using wiTECH 2.0 and the appropriate diagnostic procedures available at www.techauthority.com, verify that no DTCs are set. Check the part number of the PSDM. If the part number is 68079909AA, fl ash program the PSDM. If not, the bulletin doesn’t apply and normal diagnostic procedures should be performed to correct the problem.
After the PSDM has been updated, perform the power sliding door relearn procedure at www.techauthority.com.