Code 41, Ignition Signal Circuit No Signal
ECM tach signal is 12 volts that will vary as ignition coil is toggled to ground. The ECM uses this signal to pulse fuel injector. This code will set if there is no signal, or is constant voltage on the line.
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- This checks for battery voltage on signal line.
- This checks noise suppressor for open.
- This checks for toggling voltage signal.