P1520moderate severityPowertrain

Stop Lamp Switch Signal Malfunction

on 2002 Toyota 4Runner 3.0L V6 · 4WD

What this code means

The ECM detected a fault in the brake light switch signal circuit.

Symptoms

  • CEL
  • Cruise control inop
  • Brake lights stuck
  • Shift interlock issue

Common causes

  • Faulty stop lamp switch
  • Misadjusted switch
  • Damaged wiring
  • Poor connection

Diagnostic steps

  1. Test switch operation
  2. Adjust switch position
  3. Inspect wiring
  4. Check voltage

Repair notes

Replace or adjust stop lamp switch.

Other Powertrain codes on this vehicle

⚠ STILL BEHIND THE PAYWALL
The 2002 Toyota 4Runner repair data is incomplete because no one has sponsored it yet. For $99, we generate the full step-by-step procedures, then fact-check them with a second AI pass and your expert review. Your name on every procedure, permanently.
The same data would cost $169/mo from Mitchell1 or $30/year from ALLDATAdiy — and you'd be renting access, not freeing it. Sponsor once, free forever.
Sponsor the Toyota 4Runner — $99 →
Building an app?
Free API access to all this data — 50 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included.
Try ShopBase →