Battery & electrical

Remote start doesn't work

A remote start failure is usually caused by a weak fob or remote battery, a safety condition not being met (like the hood being open), or a system fault.

Difficulty
Easy
Time
10–30 minutes
DIY cost
$5–$20
Pro cost
$80–$250

Symptoms

  • Pressing remote start does nothing
  • Remote start works sometimes but not consistently
  • Car starts then immediately shuts off
  • Indicator lights on remote don't respond

Likely causes

  • CommonDead or weak remote/fob batteryRemote start fobs and key fobs both rely on small batteries that wear out.
  • CommonSafety condition not metMost systems won't remote start if the hood is open, a door isn't fully closed, or the brake pedal area isn't clear.
  • PossibleLow car battery voltageWeak 12V battery voltage can prevent remote start from engaging or cause it to shut off.
  • PossibleAftermarket remote start module malfunctionIf installed aftermarket, the module itself can fail or need reprogramming.
  • PossibleOut of range or signal interferenceBeing too far from the vehicle or near interference sources can block the signal.

What to do

  1. Replace the remote start fob's battery and test again.
  2. Make sure the hood is fully closed and latched, since many systems block remote start otherwise.
  3. Check that all doors are fully closed, not just appearing shut.
  4. Try getting closer to the vehicle to rule out range or interference issues.
  5. Have the 12V battery tested if remote start engages but then immediately dies.
  6. For aftermarket systems, check if the module has a reset procedure in its manual.
  7. Note any error blinks or patterns from the remote, which can indicate a specific fault code.
  8. Have the system checked by whoever installed it or a dealer if built-in, especially if it worked before and suddenly stopped.

Tools and parts

  • Small screwdriver
  • Replacement fob battery
Remote start fob batterySearch: “remote start fob battery replacement”

When to call a pro

Aftermarket remote start systems can be complex to diagnose; the original installer or a mobile auto electronics shop is often the fastest path to a fix.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.