Ignition Switch Problems? Common Symptoms to Watch For

The ignition switch is mission critical kit, it’s tasked with initating the engine starting process and taking care of some security checks. Over the years, automotive technology has evolved, resulting in different types of ignition systems tailored to enhance convenience and security.

In the old days, ignition systems directly supplied power to the ignition system and starter motor, which made them easy to steal. Today’s cars, the ignition system sends a signal or a request, if you like, to start the car, the actual power is delivered to the ignition system and starter motor by the ECU (Engine Control Unit), which acts as the vehicle’s gate keeper.

Types of Ignition Switches:

1. Traditional Mechanical Key with Mechanical Steering Lock: This system requires inserting a physical key into the ignition cylinder to start the engine. It includes a mechanical steering lock to secure the vehicle when the key is removed.
2. Electronic Key with Ignition Module: Before the widespread adoption of push-button keyless entry systems, vehicles used a keyless electronic key fob that inserts into an ignition switch module. This system electronically releases the steering lock and initiates the engine start process by signalling the ECU.
3. Keyless Entry and Push-Button Start: Many modern vehicles feature keyless entry systems where a key fob communicates wirelessly with the vehicle. A push-button start initiates the engine start sequence, offering convenience and often integrating with remote start and vehicle access features.

Immobilizer Function:

All ignition systems incorporate an immobilizer function. This security feature prevents unauthorized starting of the vehicle by requiring a specific electronic code or signal from the key fob.

In this guide, we’ll explore common symptoms indicating a faulty ignition switch, provide steps for diagnosis and replacement, and address frequently asked questions to help you keep your vehicle running reliably.

Signs of a Faulty Ignition Switch

Diagnosing Ignition Switch Issues

How to Replace Ignition

Signs of a Faulty Ignition Switch

Identifying the signs of a failing ignition switch, these symptoms vary depending on the ignition switch problem and the type of ignition switch fitted. Here are the key symptoms that may indicate an issue:

• Key Stuck in Ignition: Difficulty removing the key after turning off the engine is another common symptom. This can occur due to mechanical issues within the ignition switch or problems with the steering lock mechanism.
• Key Won’t Turn: A worn out ignition cylinder or key may not allow the key to turn.
• Intermittent Starting Issues: You may experience difficulty starting your vehicle, requiring multiple attempts to turn the key or press the start button. This can be accompanied by a noticeable hesitation or no response when trying to start the engine.
• Engine Stalling: Your engine might unexpectedly stall while driving. This sudden loss of power can be alarming and indicates a potential interruption in the ignition circuit.
• Electrical Problems: A malfunctioning ignition switch can lead to erratic behavior in electrical components. You may notice lights flickering, the radio cutting out, or power windows operating intermittently. These issues often occur without a clear pattern, making them challenging to diagnose.
• Dashboard Light Malfunctions: Watch out for unusual behavior from dashboard warning lights or gauges. A faulty ignition switch can cause these indicators to behave erratically or not illuminate properly, which may signal underlying electrical disruptions.

Diagnosing Ignition Switch Issues

The complexity and variability of ignition systems mean we have a wide range of possible failures. Mechanical systems may suffer from wear that hinders key insertion or turning, while electronic systems might encounter challenges like faulty key recognition, steering lock solenoid failure or malfunctioning electronic modules. Understanding the specific type of ignition system in your vehicle is helpful when attempting to diagnose the root cause of the issue.

In this section, we look into the basic diagnosis of ignition switch issues. We explore different types of ignition systems, their primary functions, common signs of failure, and effective diagnostic methods. Here’s an overview of the kinds of issues each system can present:

Mechanical Key and Barrel Systems:

• Key insertion or turning becomes difficult or impossible due to key/barrel wear/damage or mechanical binding.
• Wear or damage to ignition electrical contact points causing intermittent or complete failure to start.
• Failure of the key to release the steering lock, preventing the vehicle from starting.
• The ignition key code reader fault, preventing the immobilizer from turning off.

Electronic Key Fob with Ignition Module:

• Failure of the electronic module to recognize the key, leading to issues with steering lock release and engine start.
• Malfunction of the key fob itself, such as a dead battery or damaged chip, preventing authorization and ignition.
• Steering lock release failure due to a failed solenoid.

Keyless Push-Button Start Systems:

• Malfunction of the key fob itself, such as a dead battery or damaged chip, preventing authorization and ignition.
• Faulty proximity sensors that fail to detect the key fob’s presence or authorize engine start, causing issues with ignition initiation.
• Malfunction of the push-button start mechanism, leading to failure to activate the ignition and start the vehicle.
• Steering lock release failure due to a failed solenoid.

I’ve discovered the hard way that certain vehicles’ immobilizer systems can be susceptible to interference. For instance, accessories like crystal rings placed around the ignition switch or push button can cause immobilizer issues. Additionally, some vehicles may experience difficulties when parked near telecommunication towers or similar structures. It’s worth considering these factors before diving deep into diagnosis.

Before blaming the ignition switch for a no-start or no-crank issue, check for a weak battery, loose or corroded battery terminals, faulty ground connections, bad starter motor, or bad brake light switch. These common issues can often be mistaken for an ignition switch failure.

Additionally, a faulty neutral safety switch can prevent starting in automatic cars. Try shifting to “N”—if the car starts, the switch may need attention (see Symptoms of a Bad Neutral Safety Switch (And How to Fix It) for more details). Likewise, a failing clutch lockout switch in manual transmission vehicles can prevent the engine from cranking.

I’ve covered other possible causes of no crank here – No Crank No Start? Check these first!

General Diagnosis Flow:

1. Check Key Fob Battery: If your car won’t unlock, it’s a clear sign that your fob battery is flat. If you’re locked out, find the hidden blade key in the fob and use it to unlock the door handle manually. Afterward, press the start button using the fob or locate the car’s key hotspot, typically located in the center console. Alternately, replace the battery to restore functionality.
2. Visual Inspection: Visually examine the ignition switch and surrounding components for physical damage, loose connections, wear, or crystal accessories, as previously mentioned.
3. Key Insertion and Removal Test: Evaluate the ease and smoothness of inserting and removing the key. Difficulty or resistance may indicate internal mechanical wear.
4. Imobilizer Light Check: Ensure the immobilizer light goes out when the ignition is turned on (if applicable). A lit light indicates issues with the key fob, chip, or ignition code reader.
5. Diagnostic Trouble Codes (DTCs): Use an OBD scanner to retrieve relevant DTCs associated with the ignition system:
   • P1610 (NATS Malfunction): Indicates a problem with the vehicle’s immobilizer system, often linked to the ignition switch or key fob.
   • P1620 (Low Voltage to Ignition Switch): Signals insufficient voltage reaching the ignition switch, potentially due to electrical issues or a failing switch.
   • P1632 (Smart Alternator Faults): Although primarily related to alternator issues, this code can also point to underlying electrical faults affecting the ignition system.
   • B1601 (Unprogrammed Ignition Key): Indicates that the ignition key has not been properly programmed or recognized by the vehicle’s security system.
6. Check Ignition Fuses and Relays: If you have a lack of power when the ignition is turned on, inspect and test the ignition fuses and relays to ensure they function correctly.
7. Electrical Connections: If you have intermittent electrical issues, verify that all electrical connections to the ignition switch are secure and corrosion-free.
8. Functional Tests: Test the output at the starter motor when ignition switch activated (helper needed), intermittent or no activation may indicate a failing ignition switch.
9. Voltage Test: Measure voltage output across switch positions using a multimeter to identify inconsistencies.

How to Replace: Fitting a Mechanical Type Ignition Barrel

Replacing a mechanical type ignition is the most challenging type to replace and it’s the one we’ll cover here. The barrel is typically secured to the steering column using shear bolts, which must be removed and replaced. After installation, programming is required to sync the new ignition/ keys with your vehicle’s electronic systems.

It’s important to note that other ignitions, like electronic or keyless systems, are generally more straightforward, often resembling plug-and-play installations. However, regardless of the type, all replacements will require programming to ensure proper functionality with your vehicle.

And so unless you have access to programming equipment, a DIY replacement is impossible.

Follow the steps below to replace your mechanical type ignition barrel:

1. Prepare for Replacement:
   • Gather the necessary tools and replacement parts, including new shear bolts.
   • Ensure the vehicle is parked on a flat surface, the ignition is in the off position, and the battery ground cable is disconnected.
2. Remove Steering Column Covers:
   • Use a screwdriver or trim tool to remove the steering column covers to access the ignition assembly.
3. Cut and Remove Shear Bolts:
   • Disconnect electrical connectors.
   • Locate the shear bolts securing the ignition barrel to the steering column.
   • Use a drill with a metal-cutting bit or a grinder to carefully cut off the shear bolts. Take care not to damage the steering column.
4. Remove Old Ignition Barrel:
   • Once the shear bolts are removed, carefully extract the old ignition barrel from the steering column.
5. Prepare New Ignition Barrel:
   • If using a new ignition barrel, ensure it is compatible with your vehicle’s make and model.
   • Align the new ignition barrel with the steering column and secure it in place.
6. Install New Shear Bolts:
   • Insert and tighten new shear bolts to secure the new ignition barrel to the steering column. Make sure they are tightened securely.
   • Fit the ignition electrical connectors securely.
7. Reinstall Steering Column Covers:
   • Place the steering column covers back into position and secure them using screws or clips.
8. Programming and Final Checks:
   • Reconnect battery cable.
   • After replacing the ignition barrel, programming is essential to synchronize it with your vehicle’s electronic systems.
   • Follow manufacturer instructions or use a diagnostic tool to program.
   • Test the new ignition to ensure it operates smoothly, including starting the engine and verifying the steering lock functions correctly.
9. Key Management:
   • If using a used ignition barrel and key, consider the implications for door locks. You may need to purchase the matching locks or manage keys separately.
   • If managing keys separately, ensure the old key (chip) is kept away from the ignition to prevent interference with the ignition reader.
10. Final Checks:
    • Double-check all connections, bolts, and covers to ensure everything is securely in place.
    • Test the functionality of the ignition system thoroughly before driving the vehicle.

That’s it, you have successfully mastered ignition switch replacement. Nice work you!

You may find the following pages helpful:

Maintenance

Troubleshooting

OBD Fault Codes