What causes P1604 on a Honda?

Engine that cranks long or fails to start Weak battery slowing crank Failed main relay (a Honda classic no-start) Fuel delivery fault Immobilizer blocking the start

How do I fix P1604 on a Honda?

Tap-test the main relay — solder cracks are a known Honda fault Load-test the battery Check fuel pressure during crank Verify the immobilizer light goes out Diagnose the no-start cause; P1604 only records the event

P1604 Startability Malfunction (Honda)

Q: What does P1604 mean on a Honda?

P1604 — Startability Malfunction (Honda). Applies to Civic, Accord, CR-V with extended crank or no-start.

Category: Powertrain - Computer and Auxiliary Controls
Severity: Check Engine Light
Applies to: Civic, Accord, CR-V with extended crank or no-start

What does P1604 mean on a Honda?

P1604 — Startability Malfunction (Honda). This Honda-enhanced code applies to Civic, Accord, CR-V with extended crank or no-start.

Common causes of P1604

Engine that cranks long or fails to start
Weak battery slowing crank
Failed main relay (a Honda classic no-start)
Fuel delivery fault
Immobilizer blocking the start

How to fix P1604

Tap-test the main relay — solder cracks are a known Honda fault
Load-test the battery
Check fuel pressure during crank
Verify the immobilizer light goes out
Diagnose the no-start cause; P1604 only records the event