The Key won't turn all the way. It only turns half-way and will not turn the full rotation to ignite the starter in order to start the vehicle. Please help me!!!

Do you know how complex the electronics are on that vehicle ? What happens when you turn the key to start position ?
Circuit Description
Moving the ignition switch to the start position applies ignition voltage to the switch side of the STARTER relay. The powertrain control module (PCM) receives a serial data message that crank has been requested from the body control module (BCM). The PCM then verifies that the transmission is in the Park or Neutral position and that theft is not active and grounds the control circuit of the STARTER relay. Battery voltage will then flow through the switch side of the STARTER relay to the S terminal of the starter solenoid, cranking the engine. Ground for the starter is supplied through the engine block.


Hook up a scan tool an check for codes . All system scan ,all control modules on the vehicle .

Passlock™ System
The theft deterrent system has been incorporated into the body control module (BCM). The theft deterrent system is provided in order to prevent the vehicle operation if the correct key is not used in order to start the vehicle. The ignition key allows the lock cylinder to rotate. The cylinder rotation produces an analog voltage code in the Passlock™ sensor. This voltage code is received by the BCM. The BCM compares the voltage code to the previously learned voltage code. If the codes match, a serial data message is sent from the BCM to the powertrain control module (PCM). The message enables the fuel injector operation.
The design of the Passlock™ system is to prevent vehicle theft by disabling the engine unless the ignition lock cylinder rotates properly by engaging the correct ignition key. The system is similar in concept to the Passkey system. However, the Passlock™ system eliminates the need for any key mounted components. The components of the Passlock™ system are as follows:
• The ignition lock cylinder
• The ignition switch
• The Passlock™ sensor
• The BCM
• The security indicator
• The PCM


Passlock system does not keep the starter from working . Try putting the vehicle gear selector in neutral an see if the starter works then.

That is because of the vehicle theft deterrent system ! Do you have a security light lit on the instrument cluster ?
The Passlock?"¢ System is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate or the ignition switch is operated while separated from the ignition lock cylinder case. If starting is attempted without authorization from the Passlock?"¢ System, the powertrain control module (PCM) will disable engine starting. Start disable may be in the form of fuel disable or starter disable, depending on engine application.
The components of the Passlock?"¢ System are as follows:
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The ignition lock cylinder and key

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The ignition lock cylinder case, including the Passlock?"¢ sensor

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The ignition switch

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The body control module (BCM)

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The security indicator on the instrument cluster

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The powertrain control module (PCM)

Ignition Lock Cylinder Case, Including the Passlock?"¢ Sensor
The ignition lock cylinder fits inside the ignition lock cylinder case and operates the ignition switch when turned by a key with the proper mechanical cut. When the ignition key is used to turn the ignition lock cylinder to crank, start, a magnet on the lock cylinder passes close to the Passlock?"¢ sensor within the ignition lock cylinder case. The magnet activates the security hall effect sensor in the Passlock?"¢ sensor which completes a circuit from the security sensor signal circuit through a resistor to the security sensor low reference circuit. The resistance value will vary from vehicle to vehicle.
If a magnet from outside of the ignition lock cylinder case is used to attempt to steal the vehicle, the tamper hall effect sensor will be activated. This completes a circuit from the security sensor signal circuit through a tamper resistor to the security sensor low reference circuit bypassing the security resistor. If the ignition switch is forced to rotate without the correct key, or if the ignition lock cylinder is removed by force, the Passlock?"¢ sensor will be damaged and will not operate.

Do you know how to test a starter electrical circuit ?
How to voltage drop test starter motor circuit
Starter Voltage Drop
The anti- theft system has nothing to do with the cranking of the starter . Disables fuel injectors so the engine doesn't run .
The theft deterrent system has been incorporated into the body control module (BCM). The theft deterrent is provided in order to prevent the vehicle operation if the correct key is not used in order to start the vehicle. The ignition key turns the lock cylinder. The cylinder rotation produces an analog voltage code in the Passlock™ sensor. This voltage code is received by the BCM. The BCM compares the voltage code to the previously learned voltage code. If the codes match, a class 2 message is sent from the BCM to the powertrain control module (PCM)/vehicle control module (VCM). The message enables the fuel injectors.

Is there a computer related code which I must enter via the radio ??? You don't enter anything through the radio !!!!! Having factory service repair info so you can read how the anti-theft system works an a scan tool to pull DTC'S - diagnostic trouble codes is the proper way to diagnose .
The theft deterrent system has been incorporated into the body control module (BCM). The theft deterrent is provided in order to prevent the vehicle operation if the correct key is not used in order to start the vehicle. The ignition key turns the lock cylinder. The cylinder rotation produces an analog voltage code in the Passlock™ sensor. This voltage code is received by the BCM. The BCM compares the voltage code to the previously learned voltage code. If the codes match, a class 2 message is sent from the BCM to the powertrain control module (PCM)/vehicle control module (VCM). The message enables the fuel injectors.
The design of the Passlock™ system is to prevent vehicle theft by disabling the engine unless the ignition lock cylinder rotates properly by engaging the correct ignition key. The system is similar in concept to the PASS-Key® system. However, the Passlock™ system eliminates the need for a key mounted resistor pellet. The components of the Passlock™ system are as follows:
• The ignition lock cylinder
• The ignition switch
• The Passlock™ sensor
• The Body control module (BCM)
• The security telltale
• The vehicle/powertrain control module (VCM/PCM)

Your best bet , take it to a qualified repair shop.

Do you notice anything unusual with the dash lights when you turn the key on. All the warning lights should illuminate. If they do not but then come on as you start to rotate the key into the start position than you probably have a bad ignition switch.

If you turn the key to the start position and hold it there (only do this for a few seconds) will the car stay running until you let go of the key? Another clue that the ignition switch may be bad.

if you turn the key to the start position and the vehicle starts slowly let the key rotate back to the run position until the starter disengages. If the vehicle continues to run let go of the key. If the vehicle stalls than the ignition switch is definitely bad.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Sounds like your ignition (mechanical) key assembly is bad. Key should turn freely through the full cycle. Off, on, run and start. Your vehicle should have 2 ignition switches, I.e., mechanical and electronic. Sounds like you either have a bad mechanical switch or perhaps even a problem with the steering column itself.

Hello, What you are saying is the starter will turn if you jump the starter Relay. If you want to try this a second time, make sure the Ignition switch is in the RUN position. It should start.

Be sure to have the vehicle in Park. There are some Interlocks in the gearshift and Brake pedal that prevent when certain things happen. When your vehicle is in Park or Neutral, the power wire from the Ignition switch can make a connection to the wire that controls the starter Relay.

But first this wire has to get the okay from the Interlock switch, that the gearshift IS either in Park or Neutral. If this switch is bad or misaligned, the connection will not reach the starter Relay. You need to take off the small wire at the starter Relay and hook up a test light or meter. Then turn your Ignition key to START. The small wire should have power when the key is held in the start position.

If the small wire does not have power, then everything connected to that wire needs to be traced back to the Keyswitch. The cables or rods that move in the gearshift or steering column may be out of adjustment. Not too expensive to correct.

I hope my solution is very helpful to you.

Hi, if the car engine fails to crank, there is a fault in one of the components in the battery/ignition/starter circuit. Low battery (Check battery voltage, recharge if low, or jump start with another vehicle or battery charger). Bad starter relay/solenoid (Check for voltage at relay, if relay has voltage but there is no "click" when key is turned to start, replace relay). Bad ignition switch (Check to see if voltage reaches starter relay/solenoid when turn to start. If not, check for open P/N switch and brake or clutch pedal switch. Replace ignition switch if defective).

the wires to the plugs should not keep the motor from cranking over. If the battery is fully charged the ignition switch should engage the starter. If you think the firing order is wrong you need to determine 1 where is top dead center (the position the motor is in when #1 cylinder is at the top of the compression stroke). 2 what direction does the rotor turn 3 what is the firing order One way to make it easy to rotate the motor is to remove the spark plugs. no compression means no resistance to the starter so the motor should turn over with the key in the start position. If it won't crank over with the plugs out then something is wrong with the starter, battery, starter relay, or ignition switch. I always start with the basics. the battery should have at least 12.5 volts. if it does check the battery terminals. even if the starter is weak you should hear a click when the key is turned to the start position. Once you get the starter to turn over the motor you can tell when the number one cylinder is at top dead center by putting a finger over the spark hole as you crank over. You will feel the compression as the cylinder comes up on the compression stroke. I have used a large socket to slowly turn the motor over and when you are near top dead center you should be able to see the degrees of advance on the timing mark. Set the motor at top dead center then see where the rotor lines up with the wires on the distributor cap. that is where number one cylinder should fire. You then follow around in the direction that the rotor turns and the wires will corispond with the firing order. I always make a mark on the number one spot on the cap with a felt pen. That way you have a fixed reference point. Take care to verify that all the wires are to the proper plugs before trying to start. Take extra care at this point and make sure your firing order and rotor rotation are correct. I would triple check this. The firing order and rotor direction are usually somewhere on the autozone repair web site

It sounds like your telling us the key won't turn in the ignition anymore for some reason. If that is the case the problem is one or more of the tumblers in the ignition have fallen, if this is the case you will have to replace the ignition itself or at least the ignition core. If you mean the key turn but the vehicle doesn't start I would start by disabling the alarm system you installed to eliminate the starter kill switch as the source of the problem. Also, if this is the case try jumping the vehicle. If it turns over and starts with a jump your problem is the battery having a dead cell in it. It can have all the world but if you have a dead cell it doesn't have the amperage to turn the starter over.