Modern start buttons often send a low-current request to modules rather than powering the starter directly.
Why this matters
A failed push button is possible, but loss of brake-pedal input, key authorization, or module communication can produce the same no-crank symptom.
Older mechanical ignition switches can develop worn contacts that fail only in the START position.
First checks
• Confirm the vehicle recognizes the key or fob.
• Observe whether accessories and ignition mode change normally.
• Look for a start-request parameter with a capable scan tool.
• Check relevant fuses and module power supplies.
A practical test path
Begin with the easiest observation that can divide the problem into two paths. In a ignition switch and start button requests complaint, do not change several things at once. Record the initial condition, perform one test, and then decide what the result proves. If the test shows normal power, move downstream. If it shows a loss, stay with that part of the circuit until the source of the loss is found. Whenever possible, test the circuit while it is carrying its normal load rather than relying only on resistance or continuity checks with everything switched off.
For a cranking-system fault, the battery, cables, start request, interlocks, relay, solenoid, starter motor, engine mechanical freedom, and return ground form one chain. A missing result at any link prevents cranking. Measuring at strategic points is faster than removing parts.
Common mistakes to avoid • Replacing a push button because nothing happens without checking brake-switch and key-recognition data.
Stop and get help when… • Avoid disassembling steering-column lock or security components without service information.
What to record
Write down whether the symptom was present during the test, the battery voltage or scan values you observed, and exactly what changed. For ignition switch and start button requests, include temperature, key used, whether the engine cranked, and any warning or security indicators that were different from normal. Good notes prevent repeated testing and make professional diagnosis faster if you need it.