Drivable short-term, but fix now to avoid damage.
This code means the engine control module is receiving no signal at all from the 'A' high-resolution timing reference sensor. It's usually caused by a completely failed sensor, a broken or disconnected wire, or a severely damaged reluctor ring. Because this signal is essential for timing, the car often won't run properly or start, but the repair itself is usually a sensor or wiring fix rather than major engine work.
$150 – $500
Varies by vehicle and root cause.
Not reliably. With no timing pulses, the engine may stall or refuse to start at any time. It's best to have it towed or repaired before relying on the vehicle.
Most repairs land between $150 and $500. A sensor swap is on the lower end, while wiring repairs or reluctor ring damage cost more.
Yes, it's serious. A missing timing signal can leave you with a no-start or a vehicle that stalls without warning, so it should be fixed right away.
The computer needs the high-resolution timing pulse to fire spark and fuel at the right moment. With no pulses, it can't time the engine, so it often won't start or stay running.