P0351 code and how it controls your ignition
This P0351 code stands for ignition problem in the primary circuit which can cause a misfire accompanied by the flashing of the mil (malfunction indicator in the dash) light. This ICM is used by your engine computer to gather the speed signal in calculating the timing of the spark. If that signal is interrupted or out of range, a code will be set up by the ecm. When dealing with ignition control module, we are talking about 2 basic ignition system such as the one with distributor and without distributor. On the distributor system, the speed signal comes from the rotating distributor shaft monitored by the pick up coil. On system without distributor, the speed signal is gathered by the crank sensor which monitors the crankshaft rotation.
The primary circuit of the ignition coil operates on battery voltage whereas as the secondary circuit the carries the high voltage such as the one that fires your cylinder. The primary circuit includes the crank sensor or equivalent pick up coil, part of the distributor and all circuits that collects the speed signal for the engine computer. In severe cases, if the ignition module completely fails, it can cause no spark. To test, check the ICM for power supply and do the same for ignition coil. Using a test light, probe the negative terminal of the ignition coil while cranking. It should blink while the engine is being crank. If the engine has no distributor, replacing the crank sensor should fix this code.
There are many types of ignition system being used in different engines and to be able to fix this code, one has to get the symptoms of the ignition problem so we can identify the fix. Example: an ignition control module failure means replacing the distributor on one type of engine but it could be a defective crank sensor on the engine without the distributor. Also, with the correct engine designation, the correct ignition wiring could be used to troubleshoot the ignition problem.
Thanks,
