P1312 Ignition Control Module Ignition Coil Secondary Signal Circuit 2
This fault is part of the Honda misfire codes guide. It covers the system and the order to check it.
What does P1312 mean on a Honda?
P1312. Ignition Control Module Ignition Coil Secondary Signal Circuit 2. This Honda-enhanced code applies to Civic, Accord, Prelude with distributor ignition.
Common causes of P1312
- Failing ignition control module dropping the circuit 2 secondary signal
- Open or shorted coil secondary signal wire for circuit 2
- Corroded distributor or ICM connector pins
- Failing ignition coil with a breaking-down secondary winding
- Heat-soaked ICM losing the signal only when hot
How to fix P1312
- Check for spark quality on the affected cylinders with a spark tester
- Inspect the ICM and distributor connectors for corrosion and heat damage
- Test the coil primary and secondary resistance against spec hot and cold
- Scope the ICM secondary signal on circuit 2 and compare to circuit 1
- Replace the ICM or coil per the scope trace, not on suspicion
Sources and review
- Last updated 2026-09-07.