What I have researched from this...
When that happens - a lot of times the DCS didn't "set PARK" gear properly.
So if may need a little help from you --- you may have a low-charge remaining battery condition that once the engine is shut off - the Brake Solenoid that is supposed to allow the Shift lever to release - you need to keep the KEY ON - even use a battery charger - to supply enough power to allow the solenoid to disengage the parking "PAWL" the parking gear is - to bring the lever into neutral to allow you to start the engine - to finish clearing the condition caused by low-voltage.
That is if the ABOVE Post - after everything is done - can't release the transmission from PARK.
Use the Emergency brake as needed to "HOLD" the vehicle while you attempt to release the pressure on the parking PAWL - it may even need the vehicle have to be rocked gently back and forth to help reduce the locking torque - which is helped by keeping the KEY to ON - to let you use the Brake pedal in conjunction with the Emergency Brake Handle - press and hold the BRAKE Pedal not all the way to the floor - just enough so you see the rear brake lights are on - then try to adjust the shift lever from Park to Neutral - then apply the Emergency Brake (that handle) to keep the vehicle from rolling away you should be able to now get it to start.
This condition can be repeated over and over again...
- Why?
- - because of loss of vacuum in the brake booster and the Brake Light Switch is set improperly - too close to the Pushrod for the brake pedal.
- - which is keeping the Brake pedal from engaging the Brake Light which is needed to force the Body Control Module to work the Shift Lever Release solenoid
- - if you can't press down the brake pedal to get the brake lights on, it means the switch or it's housing needs to be adjusted. It's not able to "sense" the brake lights are even working as an override feature of the Module - this prevents you from even the START ability to obtain enough power from the charging system when the engine is started - to disengage the park gear from the Solenoid not being able to retract the catch - forcing / keeping the park gear engaged.
- The Brake light switch is mounted to a flange the Brake Pedal rests upon when you release the brake - the pedal rises up off the floor and rests against the flange which houses this switch.
- If the Flange is too far towards the brake housing located on the other side of the firewall in the engine compartment - the brake and the booster are going to try and apply brakes all the time - this is a clearance problem. The Brake booster is not releasing all the way to "seal" the boosters' vacuum chamber - you don't notice this because the running engine is constantly pulling vacuum all the time to keep the booster chamber in a negative vacuum condition.
- It becomes a problem when you let the vehicle sit overnight or longer - a booster with it's pushrod set to apply pressure all the time - will let air leak in and you will lose pressure. Prevents the ability to let the Brake pedal travel further down so you can then engage the Brake switch to light the brake lights.. But if the flange and switch housing are set too close to the plunger - the booster loses vacuum.
- This is due to the amount of constant pressure (spring tension and throw clearance) of the pushrod too close to the plunger itself applying pressure all the time
- You won't be able to set the Brake light on because you can't apply enough pressure to light the brake light, to overcome the lost distance the plunger will otherwise have when it's fully seated and full vacuum from the running engine can apply to fully extend the booster pushrod to "Seal" it's vacuum assist chamber..
- You have to either get it to a dealer or somehow bend/lift away the flange - away from the brake pedal - but not set the brake lights - not hard to do just tedious. Let a dealer do it. You have to get the flange - set to a distance from the brake pedal - so you're not applying pressure from the Flange and it's plunger towards the Brake Pedal all the time - causing the small leak in the vacuum which will not set a condition but will make the brake pedal harder to press down to set the Brake light.
- Part of this problem is to reset and reseat the plungers' THROW Distance to the Brakes lights. So they can come on properly as the pedal is pushed.
- Too long of a throw before the lights engage can cause a braking condition by an accident due to failure to properly warn vehicles of your stop.
- Too short, the Brake lights will be on thru every bump and even on all the time annoying drivers and potentials for causing accidents due to riding the brakes condition you didn't do - the plunger did - because it was not set properly - it provides no comfort if this was the only reason the other drivers ignored you or worse - a burnt out brake light the police didn't catch you with before this all occurred - brake lights constantly on is annoying to other drivers and is dangerous for safety's sake.
- Even a soft apply of the plunger (too close of clearance) to the pedals' flange can apply a pressure on the pushrod to cause a vacuum leak - only slightly loses vacuum over time which then makes the brake pedal act like it's hard as a rock after it is set for a while. This type of problem can also keep you being able to tell the vehicle to START - This can prevent the start condition because you can't press the brake pedal down to engage the brake lights - to clear the condition because the plunger was not seating properly.
Just some stories that were shared over coffee...
