Many newer vehicles have replaced the traditional key-style ignition switch with a push button start.
As technology advances, our lives become more convenient, but are we also putting ourselves at risk?
Will the push button start ever be perfect? It’s unlikely, but it is the way the industry is heading.
A smart key fob sends a coded security signal to the powertrain control module (PCM) via the vehicle’s keyless entry system when the fob is inside the vehicle.
This tells the powertrain control module (PCM) that the engine can be started at any time.
Before the engine will start, the transmission must be in park or neutral, and the driver must depress and hold the brake pedal.
Pressing the push button start sends a command to the powertrain control module (PCM). The powertrain control module (PCM) then checks the status of the park/neutral safety switch and the brake pedal switch. If the transmission is in park or neutral, and the brake is on, the powertrain control module (PCM) then sends a start command to the starter motor to crank the engine.
Push Button Start – Keyless Entry System – Engine Does Not Crank
If the engine does not crank when you press the push button start, any of the following may be preventing the engine from starting:
Dead Battery In Smart Key Fob
- Hold the dead key fob against the push button start button, then use the fob to press the push button start button down. This should allow the button to inductively read the security code in the fob and pass the start command to the powertrain control module (PCM). Your engine should start. Replace the dead battery inside the Smart Fob with a new battery as soon as possible.
Wrong Or Defective Key Fob
- If you accidentally picked up the wrong key fob for your vehicle, or the fob itself is defective, your engine will not start. As a result, Have your vehicle towed to your car dealer to have a new fob programmed for your vehicle.
Defective Push Button Start Button
- You have the correct key fob and the battery inside the fob is good, but nothing happens when you press the start engine button or use the fob to press the start button. You may have to replace the defective start engine button with a new one.
Dead Car Battery
- A dead or discharged car battery can prevent your engine from cranking or starting. Open the hood and check battery voltage with a voltmeter. A battery that has more than about 12.4 volts should have enough voltage to start your engine. If the battery is low or dead, try jump starting the battery from another vehicle, or hook up a battery charger to recharge or boost the battery. Also, check the battery cable connections to make sure they are clean and tight. Have your battery tested to determine its condition.
Powertrain Control Module (PCM) Problem
- If the powertrain control module (PCM) has an internal fault, or there is a problem with the anti-theft system (such as not reading the fob correctly or the security codes have gotten out of sync), further diagnosis will be necessary to determine the problem. There may be a programming issue, or a fault in the keyless entry system or keyless entry module that routes the security signal to the powertrain control module (PCM). Consequently, You will need a professional grade scan tool with bi-directional and reprogramming capability.
Faulty Starter Motor
- If the starter motor, or the relay, module or solenoid that energizes the starter is bad, the starter will not crank the engine. Try jumping the starter directly to see if it cranks the engine. This will tell you if the starter is working. The starter can also be removed and taken to an auto parts store that has a starter tester. If the starter tests bad, you need a new starter. If it tests good, the problem is not the start but likely a bad starter module, relay or solenoid. Be sure to inspect all the cables and wires that connects to the starter. Loose, corroded or damaged wire connections can prevent a good starter from cranking.
Actually this should be one of the first things to check. Locate the power center under the hood and check for blown fuses in the starter circuit. Replace as needed (always replace with same amp capacity fuse).
So, The only real difference between a push button start system and a conventional keyed ignition is that you don’t need a key to close the circuit on the ignition. The button does that. Also, Pushing the button does the same thing that turning the key does. Finally, The fob is really the beauty behind the system, which ensures that only you can start the car.
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