2015 ram 1500 active grille shutters problems

I was called to the shop to address a CEL lamp on a 2017 Dodge Ram Pickup that was recently involved in an accident (Figure 1). The body shop was all done with the vehicle but wanted to perform a POST SCAN and address the issue of the check engine light. If there were any further issues with the vehicle then a supplement would be needed to do further repairs in order to complete the insurance claim for guarantee of customer satisfaction. The last thing you need is to let a vehicle go with underlining or unforeseen issues only to have the customer come back with complaints associated with the accident. You want to prevent comebacks and bad reviews that could end up on social media putting your reputation at risk.

When I arrived at the shop, I performed a full vehicle post scan and the only codes that were in memory were stored in the Powertrain Control Module (Figure 2). The first code P1D73 dealt with a performance issue with the radiator shutters that were in front of the radiator that controlled air flow going through the radiator. These shutters are normally closed during low ambient or engine temperatures. This helps to prevent a drag coefficient across the front of the vehicle when the vehicle is in motion down the road. If additional cooling is required due to increasing engine temperatures, the Powertrain Control Module will command the grill shutter vanes to open. In colder climates, the active grille shutters may be used to improve engine coolant warm-up times rather than resulting to the old school tactic of putting a piece of cardboard in front of the radiator.

The active grille shutters are controlled by an actuator and each time the vehicle is started the PCM will initialize the shutters to fully open and then cycle back to the closed position. This helps the PCM to learn the hard stops for the shutter assembly but in it is a great diagnostic visual inspection to perform on most cars because you can at least confirm that if the vanes move then it’s guaranteed that the actuator and wiring are okay and there is no mechanical binding. If there are any issues, then the Performance code will set after a vehicle start up. If the vehicle is in a cold climate below 40 degrees Fahrenheit the PCM May assume that the shutters are frozen from ice so it may not set a code so a mechanical issue would not be detected until a warmer period start up. In this particular case I did go outside and check the operation of the shutters and they did fully open and then close on start up so I knew at this point it was safe to say that the new shutter assembly installed was operating correctly.

The second code stored in the PCM was code U11E9 that dealt with a communication issue. This shutter actor has a built-in smart module that gives it the ability to communicate with the PCM through a LIN network line. There are only 3 wires feeding the shutter actuator (Figure 3). One being a power supply, another being a ground feed and the last circuit being a LIN feed back to the PCM. The LIN circuit is used as a feedback circuit to give the PCM. Information on the position of the shutter and it will accept commands from the PCM to the position it should be in. If this “U” Code was a hard failure, then you could almost guarantee that the actuator either had a loss of power/ground feed or an open/shorted LIN circuit.

The shop did replace the entire shutter and actuator assembly (Figure 4) because it was damaged from the front-end collision. It was quite easy to just clear the codes and call it a day because everything was in working order. The LIN circuit was operational because the PCM had the ability to command the shutters to cycle on vehicle start up and the power/ground feeds were okay because the actuator was operating. The one thing that a lot of shops would never know is that there is a specific procedure you must perform on this vehicle that other manufacturers do not require. Every time those shutters are operated the PCM will start its counter and keep in memory how many times the shutter has been cycled from closed to open. This can be seen in scanner data (Figure 5). Notice that the vehicle from day one had about 13,806 commanded shutter cycles. That is some miles on that component and I’m guessing that the manufacturer is allowing the PCM to keep track of the aging factor of the actuator from a maintenance point of view.

If you put a new actuator and shutter assembly in, then this counter must be set back to zero because it is no longer the original part from 3 plus years ago. There is a functional procedure in the scan tool to reset the counter back to zero when a new one is installed. It’s basically a feature like resetting the oil life index after an oil change. This setting will stay in memory because it is in a volatile memory section of the PCM where even a low battery condition will not jar it out of the history log. It’s part of a post procedure that should be down during a front-end repair on this vehicle when the shutter assembly is replaced. I can almost guarantee you that there are plenty of these vehicles running around without this procedure ever being done and you can’t blame it on the repair technician. The manufacture should put a warning sticker on the new shutter assembly to warn the repair tech that this procedure should be done but they don’t because I’m guessing that stickers these days are expensive.

You can see the end results of the shutter reset at 0.0 Actuations (Figure 6). It was well worth for the shop to call me in to perform the Post Scan on the vehicle. When I perform vehicle scans it is not just about resetting a vehicle but it’s also gathering all the information you find and make sure anything that is associated with the codes have been corrected. There are also many Post Procedures that must be followed with each manufacture and in this case, it involved resetting the counts on the grille activations. There may also be requirements to calibrate SRS Passenger Occupant Seats for child weight or even calibrating the ABS Yaw & Steering Angle sensors. If these post procedures are not done, then the onboard systems may not function properly as designed.

My only hopes are that this article has opened your mind to realize as these vehicles get more complex it is vitally important to keep up with technology. There are always new designed systems being added on these vehicles in a never ending pace and if you are unfamiliar with the strategy of these systems you may be doing an injustice to your repair techniques if you don’t keep in the loop. I can only say that if you are reading this article along with many other trade articles in our industry then you are the true trailblazer that is keeping your head above the “Vehicles Technology Wave” and you will endure as the successor.