What causes P1566 on a Toyota?

Failed cruise control main switch assembly Open or short in the cruise main switch circuit Broken clockspring spiral cable at the steering wheel Corroded connector at the cruise main switch ECM input fault at the cruise control module

How do I fix P1566 on a Toyota?

Sweep the cruise main switch and watch the input status Test the switch circuit wiring for opens and shorts Check the clockspring spiral cable through the steering range Inspect and reseat the switch connector Replace the switch or clockspring after the tests confirm the fault Clear the code and retest

P1566 Cruise Control Main Switch Circuit Malfunction

Q: What does P1566 mean on a Toyota?

P1566. Cruise Control Main Switch Circuit Malfunction. Applies to Camry, Corolla, RAV4, Tacoma.

Category: Powertrain - Computer and Auxiliary Controls
Severity: Check Engine Light
Applies to: Camry, Corolla, RAV4, Tacoma

What does P1566 mean on a Toyota?

P1566. Cruise Control Main Switch Circuit Malfunction. This Toyota-enhanced code applies to Camry, Corolla, RAV4, Tacoma.

Common causes of P1566

Failed cruise control main switch assembly
Open or short in the cruise main switch circuit
Broken clockspring spiral cable at the steering wheel
Corroded connector at the cruise main switch
ECM input fault at the cruise control module

How to fix P1566

Sweep the cruise main switch and watch the input status
Test the switch circuit wiring for opens and shorts
Check the clockspring spiral cable through the steering range
Inspect and reseat the switch connector
Replace the switch or clockspring after the tests confirm the fault
Clear the code and retest

Sources and review

Last updated 2026-10-10.