Push-to-Start & Keyless Entry System Repair

Push-button start not working? Key not detected? We diagnose and repair PEPS systems on all makes, on-site in South Georgia.

Call Now: (912) 348-4006

30-60 Min Response

The push-to-start system -- formally called Passive Entry Passive Start (PEPS) -- is a sophisticated RF system that allows you to enter and start your vehicle without removing the key fob from your pocket. When it works, it is elegant and seamless. When it fails, the failure modes are often confusing: the car works perfectly sometimes, then randomly refuses to detect the key, or gives a 'Key Not Found' message while the fob is sitting right on the center console.

PEPS system failures are often not the key fob itself -- they frequently involve the vehicle-side antenna system, the BCM's fob-detection logic, or interference from external RF sources. Diagnosing PEPS failures correctly requires understanding the full system: the LF (125 kHz) antenna network that polls for the fob, the UHF receiver that reads the fob's reply, the BCM or SMART ECU that processes the authentication, and the start inhibit relay that gates the starter circuit.

We diagnose and repair PEPS faults on all major makes. Some repairs are straightforward (fob battery, antenna connector), others require BCM or ECU reprogramming, and occasionally a damaged antenna coil or module requires replacement. We assess the full system on-site and give you a clear picture of what is failed and what the repair involves before any work begins.

Common Push-to-Start Failure Modes

The most common cause of intermittent push-to-start failure is a weak or dead fob battery. As the battery voltage drops, the UHF transmitter in the fob loses output power, reducing detectable range before failing entirely. This presents as the system working fine when the fob is held close to the start button but failing when the fob is in a pocket or bag. A fresh battery (CR2032, brand name) resolves this instantly. Antenna faults are the next most common cause. Each PEPS-equipped vehicle has multiple LF antenna coils (typically three to five) embedded in the door handles, door jambs, center console, and dashboard. A single failed antenna creates a dead zone -- the system works when the key is near functioning antennas but fails near the broken one. Diagnosing a specific antenna fault requires a bi-directional scan tool that can interrogate each antenna coil independently, which we carry. RF interference is a frequently overlooked failure mode. Certain wireless chargers, inverters, and electronics operating on or near 125 kHz or 315/433 MHz can interfere with PEPS polling or the fob's UHF reply. Aftermarket remote start systems are a particularly common culprit -- a poorly installed aftermarket remote start can suppress the factory PEPS antenna signal or conflict with the BCM's authentication logic.

Dead or weak fob battery (most common cause, usually resolves with fresh battery)
Faulty LF antenna coil in door handle or center console
Corroded antenna connector or damaged antenna wire
BCM/SMART ECU logic fault (usually logged as a DTC, requires scan tool read)
RF interference from aftermarket accessories (chargers, inverters, remote starts)
Fob internal PCB failure (especially after water damage or physical impact)
Start button switch failure (the actual push-button contact or safety interlock)

The Brake-Start Interlock and Common Misdiagnoses

All PEPS vehicles require the brake pedal to be depressed before the start button will engage the starter. This is a federal safety requirement. A common scenario that is misdiagnosed as a PEPS failure: you press the start button without the brake fully depressed and the car enters accessory mode instead of starting. Pressing the start button again takes it back out of accessory. Pressing a third time with the brake engaged starts the engine. Users sometimes interpret this as an intermittent start failure when it is actually correct behavior. The brake light switch (which the BCM monitors to confirm brake pedal depression) can fail in a way that tells the BCM the brake is not being pressed even when it is. This prevents engine start even with a valid key and brake pedal fully floored. Diagnosing this requires reading BCM input signals with a scan tool and observing whether the brake switch signal changes state when the pedal is pressed. Brake light switch replacement is a straightforward repair and we carry common switches for Ford, GM, and Toyota applications.

When You Need This Service

'Key Not Found' or 'Key Not Detected' message appears when fob is present

Push-button start only works when holding fob directly to the button

System works intermittently with no predictable pattern

Installed an aftermarket remote start and factory PEPS stopped working

Start button illuminates but pressing it does nothing (even with brake depressed)

Door handles stopped sensing the fob for passive unlocking

Frequently Asked Questions

If I press the start button without the brake, why does nothing happen?

This is normal on all PEPS vehicles. The start button performs different functions depending on brake state: without brake pressed, it cycles through OFF, ACC (accessory), and ON (run) power states. With brake pressed, it starts the engine. This is a federal safety interlock, not a malfunction.

Can an aftermarket remote start interfere with my factory PEPS?

Yes, frequently. Aftermarket remote start modules intercept ignition and PEPS signals, and a poorly installed module can suppress the factory antenna polling frequency, prevent proper fob authentication, or conflict with BCM logic. We can diagnose whether an aftermarket module is the cause and either correct its installation or remove it.