The warning message “action required shift to park” shows that there is something wrong with the transmission system. The problem usually stops the vehicle from properly shifting to the park.
When this issue comes up, the transmission shift cable is disengaged. Once that happens, it comes with a lot of disturbing signs. Your shifter lever will move to another gear, but the transmission will not recognize the gear shift.
The vehicle will show signs like periodically turning off; the indicator will not tally with the position of the gear shift and more.
Once this happens, you must check the transmission shift cable immediately. If it is damaged, have it replaced.
What is Action Required Shift To Park?
An “action required shift to park” warning message shows something is wrong with the transmission that hinders it from shifting to park. The cause of the problem may not let the driver shift gear properly even when the shifter is working.
For instance, the driver might shift the transmission to park. However, due to underlying issues, the transmission is not actually in the park as it appears to be and can roll away at any time.
The “action required shift to park” indicates the transmission shift cable is damaged or disconnected.
What is the transmission shift cable? The cable is the link between the shifter lever and the transmission. When the driver changes the vehicle’s gear using the shifter, the cable sends a signal to the transmission, alerting the gear change. The transmission then engages the selected gear.
Once the cable is bad or disconnected, the transmission will not be notified of changes in the gear. In this case, the transmission system will not engage whatever changes in the gear. It will also trigger the warning message “action required shift to park” whenever the shifter level is in the park.
Symptoms of Action Required Shift To Park
A few symptoms come with the “action required shift to park” warning message. By observing these signs, you can better trace the issue to the transmission shift cable.
Some of the symptoms include the following.
- The indicator light will not match the position of the gear.
- Vehicle will not turn off due because the vehicle can not be shifted to park.
- Warning message “action required shift to park” will come on.
- Vehicle will remain in one gear.
- When the vehicle starts, it will begin on another gear.
Causes of Action Required Shift To Park
The primary cause of an “action required shift to park” warning message is issues with the transmission shift cable. Due to the cable’s location and condition, it is prone to stretch out.
When under intense stretching, the cable could eventually break or disconnect. Once this happens, there is a disconnection between the shifter and the transmission system.
Necessary signals will not be sent to the transmission system about the position of the gear. The driver will experience many symptoms, eventually triggering the warning message.
In addition, the shift to park issue became a significant recall for many GMC and Chevy vehicles between 2009 and 2014. The issue is still predominant among many GMC vehicles.
The primary cause of the problem with this vehicle is traced to the transmission shift cable.
However, the “action required shift to park” warning message is not only triggered by the cable; other issues, like TCM malfunction and other internal mechanical transmission issues, can trigger the warning message. You must know that these causes are rare.
Other causes of “action required shift to park” messages include the following.
1. Damaged shifter switch
The shifter switch is also called the sifter microswitch. A small electrical device activates the gear during transmission or gear shift. When the switch gets damaged, the gear will stick and shift incorrectly. It will also trigger the “action required shift to park” warning message.
2. Failing TCM
A failing TCM will activate the “action required shift to park” warning message. The TCM controls all the activities of the transmission system. When signals are sent, it receives them and acts on them based on the signals.
Once the TCM is damaged, it will go through false codes and warning messages. It will also not act on the signals transmitted to it.
How to Fix Action Required Shift To Park
Two significant causes of the shift to the park are required: damaged transmission shift cable and failing TCM.
It is quite easy to diagnose the issue because there are not many causes of the problem. You can use an OBD-II scanner to have the TCM tested for faults. Other potential causes can be physically examined.
Below are ways to fix an “action required shift to park” warning message.
1. Replace the transmission shift cable
The cable is located on the steering column or floor-mounted column. You can use the owner’s manual or seek to profess to find better signal help.
Once the cable is located, remove the front console trim plate to get to the shift cable connector. Connect the new In-line shifter harness jumper to the shift control assembly and the other end to the body harness.
Ensure the jumper is not bent at any angle greater than 90 degrees. If it is, it could increase the rate of wear and tear.
2. Clean the park switch
To clean the park switch, park your vehicle, shift the gear to park, and then turn off the engine. Go ahead to disassemble the shifter knob and boot assembly. Use a toothbrush and electric contact cleaner to brush off dirt from the contact points of the prongs of the switch.
Clean other parts leak the shifter knob and boot assembly properly and reassemble them back.
If the warning message still comes up after cleaning the switch, you may need to have the switch replaced.
3. Replace TCM
It is rare for the TCM to cause this kind of issue; however, if the OBD test shows that the TCM module is faulty then it needs to be replaced. In this case, we advise that you give a professional to have the replacement done for you.
Replacing the TCM may require professional skills. First, you will have to find a suitable TCM for your vehicle, which may require reprogramming and more.
After cleaning the park switch, replacing the TCM, and replacing the transmission shift cable, if the message keeps coming up, it is a more severe problem. It could mean an internal component in the transmission is damaged. In this case, you may need professional help.