Code 41, Ignition Signal Circuit, No Signal: Notes

ECM receives ignition signal when ignition switch is turned to ON position. When ignition is in START position, this signal is toggled on and off through ECM. As this signal is toggled on and off, it induces a voltage in secondary coil of ignition coil. This induced voltage is then used to fire spark plugs.

Code 41 will set if the toggled ignition signal is not present at the ECM within 3 seconds of cranking.

1. Checks for power at ignition coil.
2. Checks for poor connection or for a faulty ignition coil.
3. Checks for poor connection or for a faulty ECM.
4. Checks for faulty noise suppressor filter.
5. Checks for an open or short circuit to ground in wires between ignition coil, noise suppressor filter and ECM.